United States Army Japan
Assistant Chief Of Staff, G3
Foreign Histories Division
This monograph is one of a series prepared under
instruction from the Supreme Commander for the Allied Powers to the Japanese
Government (SCAPIN No. 126, 12 Oct 1945). The series covers not only the
operations of the Japanese armed forces during World War II but also their
operations in China and Manchuria, which preceded the world conflict. The
original studies were written by former officers of the Japanese Army and Navy
under the supervision of the Historical Records Section of the First (Army) and
Second (Navy) Demobilization Bureaus of the Japanese Government. The
manuscripts were translated by the Military Intelligence Service Group, G2,
Headquarters, Far East Command.
The writers were handicapped in the preparation of the
basic manuscript by the fact that many records normally used as source material
for a study of this type, were not available. Most of the important orders,
however, have been reconstructed from memory (in many cases by the officers who
wrote the original orders) and while not textually identical with the originals
are believed to be accurate and reliable. The first Japanese manuscript was
written hurriedly, much of it from memory. It was completed in November 1946.
Since then Col. Takushiro Hattori and his colleagues at the Historical Research
Institute have collected many valuable documents pertaining to the Greater East
Asia War. These have been made available to the Foreign Histories Division and
have proved most helpful in checking and correcting information in this
monograph. In addition, Lt. Gen. Monjiro Akiyama, Vice Chief, Air General
Staff; Lt. Gen. Ichiji Sugita, Commanding General, 3d Army District; Col. Shiro
Hara, Self Defense Forces; Col. Kengoro Tanaka, Self Defense Forces; Mr.
(former Colonel) Susumu Nishiura, Chief, History Section, Self Defense Forces
and Mr. (former Navy Captain) Toshikazu Ohmae, Chief, Military Operational
Analysts, Foreign Histories Division have made available many documents from
their personal libraries.
This monograph is one of a series prepared under instruction from the Supreme Commander for the Allied Powers to the Japanese Government (SCAPIN No. 126, 12 Oct 1945). The series covers not only the operations of the Japanese armed forces during World War II but also their operations in China and Manchuria, which preceded the world conflict. The original studies were written by former officers of the Japanese Army and Navy under the supervision of the Historical Records Section of the First (Army) and Second (Navy) Demobilization Bureaus of the Japanese Government. The manuscripts were translated by the Military Intelligence Service Group, G2, Headquarters, Far East Command.
The writers were handicapped in the preparation of the basic manuscript by the fact that many records normally used as source material for a study of this type, were not available. Most of the important orders, however, have been reconstructed from memory (in many cases by the officers who wrote the original orders) and while not textually identical with the originals are believed to be accurate and reliable. The first Japanese manuscript was written hurriedly, much of it from memory. It was completed in November 1946. Since then Col. Takushiro Hattori and his colleagues at the Historical Research Institute have collected many valuable documents pertaining to the Greater East Asia War. These have been made available to the Foreign Histories Division and have proved most helpful in checking and correcting information in this monograph. In addition, Lt. Gen. Monjiro Akiyama, Vice Chief, Air General Staff; Lt. Gen. Ichiji Sugita, Commanding General, 3d Army District; Col. Shiro Hara, Self Defense Forces; Col. Kengoro Tanaka, Self Defense Forces; Mr. (former Colonel) Susumu Nishiura, Chief, History Section, Self Defense Forces and Mr. (former Navy Captain) Toshikazu Ohmae, Chief, Military Operational Analysts, Foreign Histories Division have made available many documents from their personal libraries.
Japanese Monograph No. 45 tells of the establishment of Imperial General Headquarters and the many problems the Army Section of the Headquarters was faced with during the Greater East Asia War. Political and diplomatic aspects of the situation have been dealt with briefly in order to show Imperial General Headquarters relation to other branches of the Japanese Government. Navy political and military strategy prior to the outbreak of the Pacific War are described in Japanese Monographs Nos. 144, 146, 147, 150 and 152, while details of the Navy's armament plans for and during the Pacific war will be found in Japanese Monographs Nos. 145, 149, 160, 169, 172 and 174.
The first edition of this monograph was published in August 1952 but, in the light of the tremendous amount of additional information Foreign Histories Division has developed in the intervening years, it has now been completely revised and rewritten. Inaccuracies have been corrected and much pertinent data added.
The editor received valuable assistance in research from Mr. Toshikazu Ohmae and Mr. Tadao Shudo, Military Operational Analysts with the Foreign Histories Division.
11 May 1959
Contributors to Original Japanese Manuscript
The original Japanese manuscript which was used as a basis for this monograph was, in the main, written by the following former officers of the Imperial Japanese Army:
Col. Takushiro Hattori, former Chief of the 2d Section (Operations) Army General Staff, Imperial General Headquarters
Col. Keiji Takase, former staff member of the 2d Section (Operations), Army General Staff, Imperial General Headquarters
Maj. Hyuhei Nakamura, former staff member of 2d Section (Operations), Army General Staff, Imperial General Headquarters
Other former officers of the Imperial Japanese Army contributed certain specific sections of the manuscript. These were:
Lt. Col. Heizo Ishiwari, former Chief of Japanese Army History Compilation Section, Army General Staff
Lt. Col. Koji Tanaka, former staff member of 2d Section (Operations), Army General Staff, Imperial General Headquarters
Maj. Toshimitsu Fukaya, former staff member in the Department of Inspectorate General (Army Training)
Ma J. Gen. Kikusaburo Okada, former Chief of the War Material Section, War Ministry
Col. Susumu Nishiura, former Chief of Army Affairs Section, War Ministry
Col. Shinobu Takayama, former Chief of Sub-Section (Logistics) of 2d Section (Operations), Army General Staff, Imperial General Headquarters
Lt. Col. Mtchinori Ureshino, former staff member of 10th Section (Shipping), Army General Staff, Imperial General Headquarters
Lt. Col. Fumitada Shirai, former staff member of Sub-Section (Logistics), 2d Section (Operations), Army General Staff, Imperial General Headquarters
TABLE OF CONTENTS
Page CHAPTER 1 Japanese Military Command Organization 1 Imperial General Headquarters and Government Liaison Conferences 7 Conference (Council) in the Imperial Presence 9 CHAPTER 2 General Situation Before the Pacific War 12 Military Preparations 12 Training Programs 17 Expansion of National Defense Industries 24 Army Reserve Supplies 27 CHAPTER 3 Preparations for the Pacific War 30 Preparations Against a Russian Invasion of Manchuria 31 Preparations Against the Economic Blockade by the United States, Britain and the Netherlands 33 Estimate of the Enemy Situation Prior to the Outbreak of War 34 Outline of Plan for War 39 Development of the Southern Operations Plan 42 Orders of Battle for the Southern Operations 43 Missions and Objectives Assigned 45 Overall Operations Plan of the Imperial Japanese Army 49 Plans for the Capture of Hong Kong, Guam and the Bismarck Archipelago 52
Page Air Force Operational Assignments 53 Lines of Communications (Logistical Support) 53 China Expeditionary Army Operational Assignments 54 Proposed Southern Operation Military Administration 55 CHAPTER 4 First Phase of the War 57 Part 1 (Dec 1941 - Jun 1942) 57 Decision to Go to War 57 Orders to the Commander in Chief of the Southern Army 59 Orders to the Commander in Chief of the China Expeditionary Army 60 Orders to the CinC, China Expeditionary Army and the Commander, Kwantung Army in Regard to the China Incident 61 Summary of Operational Progress During 1st Phase 61 Plans for Java Operation 65 Burma Operation 68 Navy Operations in the Indian Ocean 70 Coral Sea Battle 72 Situation Review and Tentative Plans 73 Preliminary Planning for the Chungking Operation 77 Aleutians, Midway and the Southeast Area Operations Plans 82
Page Progress of the Midway and Aleutian Operations 86 Defensive Adjustments of the Southern Army in Jun 1942 87 Army-Navy Central Agreement Specifying Responsibilities in the Southern Area 89 Establishment of Air Bases in Important Southern Zones 91 Logistical Support 92 Chekiang-Kiangsi Operation 93 Part 2 (Jul.- Dec 1942) 96 Guadalcanal Operation 98 Counterattack by the 8th Fleet 99 17th Army Reinforcements 99 Surprise Enemy Landing on Makin Atoll 100 17th Army on Guadalcanal 101 Situation Review and Plans (Oct 1942) 107 Southeast Area Operations (Nov - Dec 1942) 108 Changes in Other Areas 112 Miscellaneous Actions During the Second Stage 113 Line of Communications (Logistical Support) During First Phase 115
Page CHAPTER 5 Second Phase of the War (Jan - Aug 1943) 117 Estimate of Enemy Offensive Potential 117 Orders and Operational Plans for the Southeast Area 119 General Operational Progress 123 Situation in the Central Pacific Area 130 Orders and Operational Plans for the Southwest Area 131 Troop Activities in Southwest Area Operations 135 Troop Movements in Other Areas 136 Logistical Support During the Second Phase 138 CHAPTER 6 Third Phase of the War (Sep 1943 - Jun 1944) 140 Part 1, First Stage (Sep 1943 - Feb 1944) 140 Situation Review and Estimate of Enemy Plans 140 Army General Staff Operational Plan Changes 145 Further Survey of the Situation 147 Southeast, North of Australia and Central Pacific Areas Operational Strategy 149 Army-Navy Central Agreement on Central Pacific Operations 153 Operational Preparations in the North of Australia Area 155 Efforts to Strengthen Shipping and Transportation 157 Strengthening Sea Bases 159
Page Approval to Undertake the Imphal Operation ("U-GO" Operation) 160 Directives for "ICHI-GO" Operation 162 Directives for Various Areas 167 Additional Construction and Maintenance Plans for Air Bases 169 Part 2, Second Stage (Mar - Jun 1944) 170 Situation Review and Estimate of Enemy Plans 170 North of Australia Area Directives 175 First and Second Modifications of the Second Area Army's Front Line 177 Northeastern Area Directives 178 Formosa and the Nansei Islands Directives 179 Unification of Southern Area Command System 182 Change of Mission of Southern Army 183 Central Pacific Area Directives 188 "A-GO" Operation in the Marianas Area 190 Plans to Strengthen Homeland Defenses 195 Logistical Support During the Third Phase 197 CHAPTER 7 Fourth Phase of the War (Jul - Dec 1944) 198 Summary of Operations During Fourth Phase 198 Preparations for and Development of "SHO-GO" Operations 200 Preliminary Actions Leading to "SHO-GO" Operation, No. 1 211
Page Conduct of "SHO-GO" Operation, No. 1 215 Operations in Other Areas 221 Army-Navy Discussions Regarding a Unified Air Force Command 230 Measures to Facilitate Railway Transportation on the Continent 232 CHAPTER 8 Fifth Phase of the War (Jan - Aug 1945) 234 Part 1, Situation Prior to "KETSU-GO" Operation (Jan - Mar 1945) 234 Situation Review and Conclusions Regarding United States Strategy 234 The Threat from the Soviet Union and China Increases 238 Review of Japan's Manpower and Matériel 239 Imperial General Headquarters' Operational Plans (Jan 1945) 241 Establishment of a Civil Defense Plan 245 Operational Army Mobilization Schedule 247 Southern Army Operations 250 Operations in the Central Pacific, Formosa and the Nansei Islands 256 Preparations and Disposition of Forces in Korea, China and Manchuria 261 Lines of Communications (Logistical Support) During this Period 265 Homeland Operations and Strategy 266 Air Operations and Enemy Bombing of the Homeland 273
Page Part 2, Preparations for "KETSU-GO" Operation (Apr - Aug 1945) 283 Operational Preparations Resulting from Situation Estimate 283 Lines of Communications (Logistical Support) Preparations 288 Transportation 289 Communication System Preparations 291 Troop Employment 292 Army-Navy Strategic Collaboration 294 General Military Preparations and Disposition of Fighting Forces 295 Situation in Korea 298 Direction of Operations Against Enemy Invasion of Okinawa 299 Plans for Operations and Reorganisation of Forces in the China Theater 306 Operational Preparations Against the Soviet Union 310 Preparations for the Defense of the Homeland from Jun 1945 316 Air Operations 318 Situation After the Fall of Okinawa 327 Continental Organization Revisions and Operations 329 Operations Following the Soviet Entry into the War 333 Lines of Communications (Logistical Support) During Fifth Phase 336 Termination of Hostilities 337
Page No. 1 Regular Members of the Liaison Conference, Jul 1941 to Aug 1945 11 No. 2 Number of Divisions, 1937 to 1941 15 No. 3 Army Air Forces, 1937 to 1941, Army Conscription, 1936 to 1941 16 No. 4 Disposition of the Army Ground Units, Dec 1941 18-19 No. 5 Army Operational Supplies, Dec 1941 20 No. 6 Disposition of the Army Air Units, Dec 1941 21 No. 7 Estimated Army Strength of the Enemy in the South, Sep 1941 35-36 No. 8 Estimated Enemy Air Strength in the South, Sep 1941 37 No. 9 Estimated Enemy Naval Forces Operating to the South, Sep 1941 38 No. 10 Estimate of the Enemy Strength, May 1942 78-79 No. 11 Estimate of Possible Increases in U.S.-British Plane and Tank Production, May 1942 80 No. 12a SHO-GO Operations Air Strength; Army Air Strength Employment Outline 206 No. 12b SHO-GO Operations Air Strength; Navy Air Strength Employment Outline 207 No. 13 Plan for Reimporting War Matériel from Manchuria to Japan and Korea 267 No. 14 Estimated Army Air Strength, End of Mar 1945 277 No. 15 Estimated Naval Air Strength, End of Apr 1945 278
Page No. 16 Revised System of High Command 286 No. 17 Plan of the Army General Staff for Movement of Land Forces During KETSU-GO Operations 293 No. 18 Strength of Army Air Force, End of May 1945 305 No. 19a Disposition and Utilization Plan of the Air General Army 324 No. 19b Disposition and Utilization Plan of the Navy Air Forces 325
No. 1 Army Department Directives and Orders 344 No. 2 Chronology of Major Events During War 364 No. 3 Chronology of Major liaison Conferences During Greater East Asia War 369 No. 4 Chronology of Major Actions and Decisions by the Army General Staff 371 No. 5 Guide to Designation of Units, Their Missions and Normal Size 381 Index 385
Japanese Military Command Organization
On 11 February 1889 Emperor Meiji announced the promulgation of the new Constitution. It spoke first of the Emperor. He was declared to be sacred and inviolable, in a line which had been "unbroken from ages eternal." He was the source of all authority and combined in himself all sovereignty. His was the supreme command of the army and navy. With him rested the declaration of war and the making of peace. He was to sanction all laws and to order them promulgated and executed. He was to convoke and prorogue the Diet and, when that body was not in session, he could issue ordinances which had the force of law. In practise these various functions were performed by his ministers, who were responsible directly to the Emperor and not to the Diet, although that body could embarrass them and impede their program. Government was in the name of the Emperor but he did not openly make decisions and his ministers assumed responsibility for his acts.
Army and Navy General Staff regulations developed to implement Clause 11 of the Constitution provided for the execution of and responsibility for operational requirements necessary to support and protect the Emperor as Supreme Commander.1 In 1893 the positions
of Chief of the Army General Staff and Chief of Navy General Staff were created to provide the necessary assistants to advise the Emperor as Supreme Commander, with the General Staff Regulations of 1893 specifically setting forth their duties and responsibilities.
Gradually, institutions and practises outside the Constitution, but not in violation of it, arose, which had a tremendous impact on the destiny of Japan. One of these was that by which the Army and Navy could exert important influence upon the formation of cabinets. At the turn of the century it was decreed by an ordinance published by the Privy Council that the Minister of the Navy must be a high ranking naval officer and the Minister of the War a high ranking army officer on the active list (Admiral or Vice Admiral for the Minister of the Navy and General or Lt. General for the Minister of War). In addition, it stated that the Ministers of War and Navy would have direct access to the Emperor. As this meant that no one could serve in these positions without the consent of the inner circle of the respective services, the Army and Navy, if so minded, could prevent the formation of a cabinet and could see that the holders of the other portfolios, at least in part, conformed to their policies. This made the Army and Navy largely independent of civilian control. Indeed, by their privilege of being able to go directly to the Emperor, the Ministers of War and Navy and, therefore, the armed services, could obtain Imperial sanction for actions
without the concurrence or even the previous knowledge of their colleagues in the Cabinet, The Diet, however, with its partial control of the budget could restrain the Army and Navy to some degree.
Even in wartime, separate responsibility to the Throne was still held by the respective Chiefs of Staff for their specific branch of service. Although the Ministers of War and the Navy, the Chiefs of the Army and Navy General Staffs, and the Inspectorate General for Army Training separately and collectively advised the Emperor directly on matters of national defense, strategy and tactics and assumed responsibility for the outcome of actions taken, this did not break the basic responsibility of the Chiefs of the Army and Navy General Staffs.2 When required, the Board of Marshals and Fleet Admirals and the Supreme Military Council were called in to give advice in regard to their respective services, but this was only at the request of the Emperor.
Where joint command action was required in the progress of war, Central Agreements were arrived at by the two Chiefs of the General Staffs through joint staff studies. It is important to emphasize, however, that by far the greater number of orders and directives issued by the Central Authorities were independent Army or Navy actions
covering their individual responsibility to the Throne. Army field commanders, though directly responsible to the Emperor, could not report directly to the Throne but presented their recommendations through the Chief of the Army General Staff. It was customary for the War and the Navy Ministers and the Chiefs of the General Staffs to notify each other of matters taken directly to the Emperor and Cabinet regulations made it mandatory that such matters would be reported to the Premier through the Ministers. If the Emperor considered the subject of sufficient importance, he would then call in the Premier for consultation.
The joint responsibility held by the government (appropriations) and the military (planning) was designated "Concurrent Affairs." This principally affected the Army and Navy in their organization and standing troop strength but also included the authority needed to construct and maintain military establishments, establish military standards, publish regulations and make disposition of units and supplies. Concurrent Affairs for the Army were handled by the War Minister, Chief of the General Staff, Inspectorate General for Army Training, and sometimes the Inspectorate General for Army Aviation, according to their authority and department requirements. The respective chief was responsible either independently or jointly with the other chiefs, with the War Minister finally responsible for the execution of all matters. Regulations specifically set
forth the authority of each chief in handling Concurrent Affairs. In addition to the regulations, there was mutual agreement establishing the areas of responsibility of the War Minister, the Chief of the General Staff and the Inspectorate General for Army Training.
The War Minister handled such matters as the standards and design of weapons, finance, sanitation, veterinary and judicial affairs. In peace time he was responsible for national defense, military training and special inspections of military training and installations.
Matters handled by the Chief of the General Staff included the use of troops for maintaining local public order; the dispatch, duty and relief of overseas expeditionary forces; wartime organizations; mobilization plans and grand maneuvers.
The Inspectorate General for Army Training was responsible for establishing military training regulations as well as drill regulations and manuals for the various branches of the service.
Orders were issued on Concurrent Affairs in accordance with Military Order No. 1 of 1907. These orders were in the form of army or navy pronouncements over the signature of the War or Navy Minister and were treated as military orders. The War or Navy Minister was held responsible for their execution. This system was developed to cover matters of mutual interest to the military and civil authorities when the outcome affected the armed forces.
Military Order No. 1 of 1907 contained the following clauses:
Clause 1: Regulations concerning the supreme command of the Army and Navy will be in the form of military orders sanctioned by the Emperor. Clause 2: Military orders must be publicly announced over the signature of the responsible War or Navy Minister. They will be accompanied by an Imperial edict bearing the Imperial signature and seal. Clause 3: Military orders will be published in the official gazette. Clause 4: Unless a specific date is stated, military orders will become effective immediately upon publication.
The War Minister, in his capacity as a member of the Cabinet, carried out government policy and advised the Emperor on important matters concerning military administrative affairs. He was responsible for the consolidation of civil and military affairs of state and acted as a liaison in achieving cooperation between the military supreme command and other government departments. As stated earlier, it was the custom for the Army and Navy to recommend candidates to the Premier for the positions of War and Navy Ministers. Usually within the Army, the "Big Three" - the Chiefs of the Ministry, General Staff and Inspectorate General - met and decided who should be offered the post. In theory it was then left up to the Premier to decide whether such a nomination was acceptable. In fact, however, he had to accept the nomination in order to form his cabinet.
Imperial General Headquarters and Government Liaison Conferences
Prior to the China Incident, the Chiefs of the Army and Navy General Staffs had advised the Emperor directly on matters of national defense, war planning and command. On 17 November 1937, with the spread of the Incident, Imperial General Headquarters was established to control the armed forces likely to be involved. The ordinance creating it termed the agency the "highest body of the Supreme Command." It was placed under Imperial supervision and required the Chiefs of the Army and Navy General Staffs to assist the Emperor. Members of the Headquarters (in addition to the Chiefs of Staff) were the Ministers of War and the Navy and other specially appointed officers. At one time some thought was given to including the Premier as a member of Imperial General Headquarters but, after due consideration, this was considered unwise. Shortly afterwards, the Ministers for War and the Navy and the two Chiefs were grouped as a Liaison Committee between the Cabinet and Imperial General Headquarters. The Liaison Conference system was developed to coordinate matters of joint importance to Imperial General Headquarters and domestic or foreign affairs without legislation. Although at various times the name of the Liaison Conference was changed, to include the "Liaison Conference between Imperial General Headquarters and the Government," and "Supreme War Direction Conference," and there was some modification of its form and methods, the basic conference
principle was maintained until the termination of hostilities in 1945, with no changes in the funda
After the formation of the second Konoye Cabinet on 22 July 1940 national and foreign policy decisions became increasingly important. The liaison Conference was called upon to act as the Supreme War Council and governmentally was of immense importance. Additional references to the liaison conference system in the text are referred to as the "Conference."
Whereas the Conference was established by mutual agreement between the Government and the Supreme Command, a Cabinet Council was provided for legislatively in the Constitution. Members of the Conference were jointly and individually responsible to see its decisions were executed properly by the Government and/or the Supreme Command, according to the respective function. In contrast, Cabinet
Council decisions were authorized by regulations providing for cabinet organization.3
Although the Conference had no legislative authority and its decisions were subject to mutual agreement, it received the full support of both the Supreme Command and the Government and had the authority to decide upon and conduct war.
The Conference in no way changed the alignment of responsibilities. State Ministers still assumed full responsibility for state affairs and acted as advisers to the Throne on all state matters, and the two Chiefs of Staff assumed full responsibility for and had direct access to the Emperor on all matters concerning the military command. This was entirely separate from the State Ministers joint responsibility on Concurrent Affairs decided upon at Cabinet meetings.
In making formal reports to the Throne for approval, the Conference made the reports over the signatures of the Premier and the two Chiefs of Staff, or all three reported in person. The execution, after approval, however, remained as before with state affairs being handled by the Premier and military command matters being handled by the two Chiefs of Staff. The idea of joint signatures was developed for liaison purposes in reporting to the Throne.
Conference (Council) in the Imperial Presence
This type of conference was held in the presence of the Emperor but was not presided over by the Emperor. Imperial Conferences were held to discuss important national policies in the presence of the
Emperor so that he might be fully informed. Decisions made at such conferences, however, still had to be confirmed by legislative procedure.
The decision to end World War II was reached at an Imperial Conference. Here, however, departing from accepted practice the Emperor was reported to have made a personal decision at the Conference. Actually, he merely expressed a desire and the decision became effective, as always, through Council and Cabinet action.
A typical Conference agenda called for the discussion of important national policies, such as a fundamental plan for the conduct of war; important diplomatic measures; regulations in regard to military operations and national power; the administration of occupied territories and the disposition of such territories. Those present representing the government were the Premier, the Foreign Minister, the War Minister and Navy Minister. The supreme command was represented by the Chiefs of the Army and Navy General Staffs, (it was customary for their vice chiefs to attend to assist the Chiefs of Staff). In addition, State Ministers could attend to discuss certain specific subjects and Cabinet Ministers could be called in when required. If the Emperor were present, the President of the Privy Council always attended the meetings.
Chart No. 1
Regular Members of the Liaison Conference
July 1941 - August 1945
Period/Position Premier Foreign Minister War Minister Navy Minister Chief of Army General Staff Chief of Navy General Staff 18 Jul 41 - 18 Oct 41 (Third Konoye Cabinet) Prince Ayamaro Konoye Admiral Teijiro Toyoda General Hideki Tojo Admiral Koshiro Oikawa General Gen Sugiyama
--22 Feb 44--
General Hideki Tojo
Admiral Osami Nagano
--22 Feb 44--
--2 Aug 44--
Admiral Koshiro Oikawa
--29 May 45--
Admiral Soemu Toyoda
18 Oct 41 - 22 Jul 44 (Tojo Cabinet) General Hideki Tojo Shigenori Togo
--2 Sep 42--
--20 Apr 43--
General Hideki Tojo Admiral Shigetaro Shimada 22 Jul 44 - 7 Apr 45 (Koiso Cabinet) General Kuniaki Koiso General Gen Sugiyama Admiral Mitsumasa Yonai General Yoshijiro Umezu 7 Apr 45 - 17 Aug 45 (Suzuki Cabinet) Admiral Baron Kantaro Suzuki Shigenori Togo General Korechika Anami
Remarks: a. During the Tojo Cabinet, the Finance Minister (Okinobu Kaya and, after 19 Feb 44, Sotaro Ishiwata) and the President of the Planning Board (Lt. Gen. Teiichi Suzuki) were designated regular members of the Liaison Conference.
b. When the Emperor was present, the Conference was named a Council in the Imperial Presence and the President of the Privy Council attended. The Presidents were Yoshimichi Hara until 10 Aug 44, Adm Kantaro Suzuki from 10 Aug 44 until 7 Apr 45 and Baron Kiichiro Hiranuma from 7 Apr 45 until the end of war.
General Situation Before the Pacific War
Immediately after World War I the Imperial Japanese Army was small in size and poorly equipped in comparison with the armies of other world powers. The outbreak of the China Incident, following the Manchurian Incident, however, compelled Japan to build up its army in size and quality, both as a means to quickly terminate the China Incident and also as a defense against the ever-present threat of a war with the Soviet Union.
In April 1941, Japan signed a non-aggression pact with the U.S.S.R. and, in June, Germany invaded Russia. Japan, being a member of the Tripartite Alliance, was gravely concerned and called a conference to determine how best to protect her interests in north China and Manchuria. Japan wished to avoid war with the U.S.S.R. if at all possible, but felt it wise to increase its military strength to be prepared should the Soviets decide to move down from the north.
At the end of July 1941, the United States, Britain and the Netherlands broke off economic relations with Japan. At first, it was hoped the situation could be solved by diplomacy, and it was not until September that Japan felt forced to prepare for war against these countries should diplomatic negotiations fail. Even
then, there was no massive mobilization of forces but rather it was agreed that, should war in the south prove inevitable, the necessary forces would at first be drawn from the China theater and the standing army in Japan. The main preparations before the final decision to go to war was reached were confined to the requisitioning and fitting of ships, the shifting of operational personnel, the establishment of air and sea transportation bases and base depots, the stockpiling of munitions and the strengthening of Homeland defenses. The activation of operational forces and their concentration and deployment in the Southern Area was undertaken only after war was declared.
Earlier, success in the Sino-Japanese and Russo-Japanese wars had reduced the menace from China and Russia and had given Japan some holdings in China. Furthermore, Japan had increased her rights on the Continent by economic and political agreements. Before the Manchurian Incident, Japan's military peace time strength was only about 17 divisions which could have been increased to 30 divisions in case of war. In 1931, the Manchurian Incident broke out. With Russia's obvious expansion of military force in the north and its pressure against Manchuria, Japan was compelled to increase her military strength for national defense. The Army General Staff estimated that Japan would require 60 divisions in peace time and 90 to 100 divisions in war time to defend her rights but the economy of
the country could not support this increase. The government approved an army-sponsored bill to increase the army by six divisions in 1936, and between 1937 and 1938 approved a plan to add a further 14 divisions by the end of 1943. It, however, was unable to grant the appropriations for this continuing project immediately, so that each year it was necessary for the Army to request an appropriation to cover the financial needs for the following year.
From 1938 to 1941, the combat zone in China was gradually expanded while, at the same time, the necessity for defense against Russia increased. To cope with this situation, a gradual build-up in forces was undertaken each year. In this way it was hoped that the China Incident could be concluded and security developed against the U.S.S.R.
The increase in strength of Army and Army Air Force and the mobilization of officers and enlisted men between 1937 and 1942 are shown in Chart Nos. 2 and 3.
Although the gradual build-up of the Army enabled Japan to enter the Pacific War with an augmented force, the increase in strength had not been planned with this objective. The primary aims of this increase in strength were the successful conclusion of the China Incident and the protecting of Japanese interests in Manchuria against Soviet aggression. Proof that the Army was not enlarged for the purpose of waging large-scale war is provided by the fact that increases
Chart No. 2
Number of Divisions
(1937 to 1941)
Disposition \ Year 1937 1938 1939 1940 1941 Homeland and Korea 3 2 7 11 11 Manchuria 5 8 9 12 13 China 16 24 25 27 27 Total 24 41 50 51 Remarks: 1. From 1937 to 1940, the number of divisions is shown as of the end of each year, while in 1941, the total as of early November is shown.
2. In addition one cavalry group was deployed in North China from 1937 through 1941. The strength of this group was less than a division but larger than a brigade.
Chart No. 3
Army Air Forces
(1937 to 1941)
Classification \ Year March 1937 March 1938 March 1939 March 1940 Nov. 1941 Fighters 21 24 28 36 56 Light Bombers 12 16 26 28 36 Heavy Bombers 9 17 19 22 27 Reconnaissance Planes 12 13 18 20 32 Total 70 91 106 151 Remarks: The figures show number of squadrons as of March of each year. About a year was required after the activation of a squadron before the newly organized unit could reach actual combat strength.
(1936 to 1941)
Year 1936 1937 1938 1939 1940 1941 Personnel 170,000 170,000 320,000 340,000 320,000 330,000
were always far less than required. The four-year build-up never achieved sufficient strength to strike a decisive blow in China and Japanese forces in Manchuria never exceeded one-third of the strength of the Soviet forces deployed along the Manchurian border.
In December 1941, the Army's total strength consisted of 51 divisions, one cavalry group, 59 brigade-size units of various types, and approximately 40 air regiments.
The disposition of forces and the type, quantity and location of supplies, at this time, are shown on Charts Nos. 4, 5 and 6.
An additional report showed that prior to July 1941 the stockpiles of ammunition and aviation fuel were located approximately as follows:
Homeland Manchuria China Southern Area Ammunition 52% 19% 29% -- Aviation Fuel 80% 16% 4% --
In July, 27% of the entire stock of ammunition and 14% of the aviation fuel were transferred from the Homeland to Manchuria. A further transfer was made immediately before the outbreak of hostilities in the Pacific with 13% of the ammunition and 12% of the aviation fuel being transferred from the Homeland to the Southern Area.
Such manuals and regulations as the "Military Training Regulations," and the "Field Operations Service Regulations" used by the
Chart No. 4a
Disposition of the Army Ground Units
Area \ Classification Name of Hq Location Divisions No of
Homeland Korea Formosa Gen Defense Cmd Tokyo 0 (a) Eastern Army Cmd Tokyo 52d 4 Central Army Cmd Osaka 53d, 54th 3 Western Army Cmd Fukuoka 3 Northern Army Cmd Sapporo 7th 1 Korea Army Hq Seoul 19th, 20th Formosa Army Hq Taihoku Manchuria Kwantung Army Hq Changchun 10th, 28th, 29th 1 3d Army Hq Mutanchiang 9th, 12th 4 4th Army Hq Peian 1st, 14th, 57th 5 5th Army Hq Tungan 11th, 24th 4 6th Army Hq Hulun 23d 1 20th Army Hq Chihsi 8th, 25th 4 Kwantung Defense Cmd Changchun 5
Chart No. 4b
Disposition of the Army Ground Units (Cont'd)
Area \ Classification Name of Hq Location Divisions No of
China China Exped Army Gen Hq Nanching North China Area Army Hq Peiping 27th, 35th, 110th 5 1st Army Hq Yangchu 36th, 37th, 41st 3 12th Army Hq Licheng (Chinen) 17th, 32d 3 Mongolia Garrison Army Hq Wanchuan 26th, Cav Gp 1 11th Army Hq Hankou 3d, 6th, 13th, 34th, 39th, 40th 2 13th Army Hq Shanghai 4th (b), 15th, 22d, 116th 5 23d Army Hq Canton 38th, 51st, 104th 1 The South Southern Army Hq (Gen) Saigon 21st (c) 1 14th Army Hq Takao 16th, 48th 1 15th Army Hq French Indo-China 33d (c), 55th 16th Army Hq Takao 2d 1 25th Army Hq Sanya Guard, 5th, 18th, 56th (c) South Seas Det Ogasawara Is 1 Remarks: a. In addition, 12 depot divisions were located in Japan.
b. The 4th Division at Shanghai was placed under the direct command of IGHQ at the outbreak of the Pacific War.
c. Actual dates for transfer of command were departure dates from previous stations: 21st from Chingtao (20 Jan 42); 33d from Nanching (13 Dec 41); and 56th from Japan (16 Feb 42).
Chart No. 5
Army Operational Supplies
Location of Depots Homeland South Manchuria China Ammunition One Division in a standard campaign 105
30 Motor Car Fuel 1,000 cars for one month 357
140 50 125 42 Aviation Fuel & Ammunition One Air Brigade for one month Ammo 77
Rations One Division for one month 370
103 83 Remarks: The figures shown in parenthesis represent supplies produced during December, and are included in the figures without the parenthesis.
Chart No. 6
Disposition ofthe Army Air Units
Area \ Classification Unit Location of Hq Number of Air Regt (Indep Squadrons) Total Fighter Lt Bmr Hv Bmr Reconnaissance Direct Support No of Regt (Indep Sq) No of Sq Homeland 1st Air Gp Kagamigahara 2 1 3 9 Manchuria Air Corps 2d Air Gp Mutanchiang 5 4 1 (2) (3) 10 (5) 17 (5) 56 Directly Attached Unit Changchun 3 1 3 7 China 1st Air Brig Nanching 1 (1) 1 (3) 1 (2) 3 (6) 16 The South 3d Air Gp Phnom Penh 5 4 4 1 (5) (1) 14 (6) 19 (12) 70 5th Air Gp Heito 2 2 1 (3) (1) 5 (4) 21st Indep Air Unit Hanoi (1) (1) (2) Grand Total 18 (2) 12 9 2 (14) 1 (7) 42 (23) 151 Remarks: a. The figures in parentheses represent the number of independent air squadrons.
b. There were some air regiments, such as the 3d and 4th Air Regiments, in the Homeland. These units were charged with air training and were not suitable for operational strength.
various branches of the Army as training standards had not been changed since World War I. These manuals emphasized the importance of mobile combat tactics; the adoption of an encircling attack; importance of close combat; encouragement of night attacks; the training of officers and men to be self-reliant, and the necessity to develop a fully qualified soldier within the two years of his enlistment.
Prior to the Manchurian Incident training had been strictly according to the manuals with no idea of training against any one particular enemy. With the outbreak of the Manchurian Incident, training emphasized possible tactics for use in Manchuria against Russia. Even after the China Incident began in July 1937, there was little cha
nge in these training methods.
As in both incidents the Japanese Imperial Army had engaged a poorly equipped, inferior enemy, success had caused a definite relaxation in training standards. Following the hard-fought battles against the Soviets at Changkufeng in 1938 and Nomonhan in 1939, however, training was stepped up and emphasized systematic, scientific fighting techniques and realistic combat training. Unfortunately, the standard of training was still not high as there were not sufficient qualified officers to instruct the large numbers rapidly being mobilized to cope with the China Incident.
In consequence, the Army's training for the Pacific War was inadequate. In early 1941, the Army General Staff developed traini
ngschedules to include countermeasures against United States and British, as well as Soviet, tactics. Data was collected and fighting methods studied, but time prevented gaining the desired results in training. In June 1941, an enlarged tactical training program was initiated for specific units in Formosa, south China and French Indochina and some reference books, to include "Characteristics of Operations in the Torrid Zones," "Conventional Tactics of the United States and British Forces," and "Simplified Southern Operations," were published to assist the training program. The material gathered, however, was very poor and of little use. In addition, as the China Incident continued, it became more and more difficult to provide additional training for the troops stationed there.
Subsequent to the outbreak of the China Incident, such field exercises as the Special Grand Maneuver, General Officers' Maneuver and the Staff Officers' Maneuver were suspended and the study and training in strategy and tactics was generally regarded as completely inadequate to wage war against the United States and Britain. In fact, although most of the operations in the Pacific would have to commence with amphibious landings, very few of the troops had any training whatsoever in this type of warfare.
For several years investigations of air tactics were conducted.
In 1939 and 1940 it was agreed that the most satisfactory method of attack was the concentrated use of air power against major targets, and that concentrated air power was also the best means of directly supporting land forces. Intensive training in these tactics was therefore conducted. This led to outstanding results in the initial operations of the Pacific War.
Expansion of National Defense Industries
Prior to the Manchurian Incident, as with her training program, Japan's armament was many years behind that of other world powers. In 1936, methods to modernize Japan's military strength were carefully studied. Years of neglect in developing new weapons and armament, however, greatly hampered this project. The basic national defense production capacity was small. There were not sufficient munitions factories and the few that existed operated on very low budgets.
In the spring of 1937, the Army prepared a budget and submitted a five-year plan for the munitions industry, stressing the need for the expansion of basic industrial facilities to support the munitions increase. The legislature, however, refused to consider the plan. The Army then drafted a five-year plan for bolstering such basic industries as the processing of iron ore, development of hydroelectric plants, development of synthetic oil and the manufacture of machine tools. This need was emphasized by the demands of the
China Incident in July and August 1937, which brought to light many weaknesses in Japan's national defense industries and the necessity to nationalize munitions industries, Russia's threat in the north further highlighted the need to modernize Japan's war industries. On 5 September 1937, the Diet approved these industries being placed under military control and, in March the following year, the National Mobilization Law was passed incorporating most of the Army's demands. From then on, production was accelerated. Originally the plan to expand the munitions industries had been limited to six months, but as the China Incident dragged on, the budget was renewed each fiscal year. With the enactment of the National Mobilization Law the necessary economic control regulations were gradually developed to provide authority to execute the necessary actions to fulfil the objectives of the Army's five-year plan.
In Manchuria, the basic industries plan got under way immediately but in Japan the first year was taken up by planning as Japan, because of the China Incident, was cut off from many of the sources of natural resources, particularly iron ore. This led to many of the quotas having to be reduced.
Under the plan aviation, munitions and parts manufacturing industries were greatly expanded. Steel and machine tool industries were remarkably successful and the light metal industry made rapid progress. The manufacture of synthetic oil and the development of
hydro-electric power, however, were very disappointing, due to the lack of essential materials. An attempt was made through a trade agreement with Germany to obtain the necessary synthetic oil production equipment and generators for hydro-electric plants, but the war in Europe intervened and made this impossible.
Efforts were made to stockpile oil through a trade agreement with the Netherlands but this also failed. During both the second Konoye and Tojo governments many efforts were made to solve this problem of lack of oil but without success. Lack of oil not only affected the manufacture of munitions and all other war preparations but also seriously affected the economy of the entire country.
In spite of this, little by little, the munitions industry was built up, until by the end of 1940, it was capable of not only fulfilling mobilization requirements but replacing battle losses. Just before the Pacific War a report was submitted estimating the industrial production capacity as follows:
Yearly Production Capacity Schedule Classification 1941 Fiscal Year 1942 Fiscal Year 1943 Fiscal Year Army Planes approx 3,500 approx 5,300 approx 10,000 Tanks approx 1,200 approx 1,500 approx 1,800 Ground Ammunition (required by one division for a standard campaign) 43 battles 50 battles 50 battles Bombs (required by one air brigade by months) 22 months 80 months 80 months
Army Reserve Supplies
Raw materials to be made into weapons, ammunition and clothing had been satisfactorily accumulated but no attempt had been made to stockpile petroleum products prior to the China Incident. In 1936, when the military armament build-up was planned, only 200,000 koku (less than 40,000 kiloliters) of aviation fuel was allocated for reserves during the next few years. In the fall of 1937, however, anticipating complications in foreign trade relations because of the China Incident, the necessary crude oil for manufacturing approximately 150,000 kiloliters of aviation fuel was imported from the United States. This was judged sufficient to carry out operations in China for one year. This procedure was repeated several times;
the last shipment being in the spring of 1941. Similar measures were taken to replenish tool machines and important supply reserves, such as tungsten and nickel, stocks of which had become seriously depleted, faced with threatening world conditions in 1940, the Army demanded that government departments each import and maintain a reserve of the stocks for which it was responsible. It specified a three-year supply as desirable and a two-year supply as a minimum. The oil stockpile (including Army and Navy) at the end of March 1941 was:
Aviation gasoline approx 1,170,000 kiloliters Ordinary gasoline " 830,000 " Kerosene " 320,000 " light oil " 320,000 " Heavy (crude) oil " 4,430,000 " Machine oil " 360,000 "
The Army and Navy oil requirements for the fiscal year of 1941, (mainly for the China Incident) were:
Aviation gasoline approx 150,000 kiloliters Ordinary gasoline " 80,000 " Kerosene " 10,000 " Light oil " 4,000 " Crude oil " 1,030,000 " Machine oil " 150,000 "
In July 1941, when the United States, Britain and the Netherlands placed an embargo on oil, it was estimated that approximately 850,000 kiloliters of aviation gasoline and approximately 2,350,000 kiloliters of crude oil were available, in addition to the estimated requirements for conducting operations in China for another two years. This meant that the Army and Navy Air Forces had sufficient oil to operate at full strength for approximately one year and that the Navy surface forces, if called upon to conduct a delaying operation, could continue to function for approximately one year but, in the case of continuous warfare, could operate for less than six months.
Preparations for the Pacific War
In spite of all efforts to localize the China Incident, it continued to expand. More and more forces became involved.
In 1939, 25 Japanese divisions were being used in China for combat, occupation of major cities and protection of supply lines. That year the Soviet Army had about 20 sniper divisions and approximately 1,000 planes in east Russia along the outer border or Manchuria, while the Japanese Kwantung Army had only six to eight divisions, 300 to 400 planes and 300 tanks stationed in Manchuria to defend that area.
Under these circumstances, and with the limited arms and materials available, it was not considered feasible for Japan to sustain an engagement with any third power. Constantly changing world conditions from 1940 onward, however, forced Japan to face the fact that there was a great possibility that she would be compelled to fight the United States and Britain if she were to maintain her independence as a nation. To protect her entity, therefore, while the plans being studied in the summer of 1941 were concerned mainly with the affect of the Soviet-German war on Soviet-Japanese relations, plans also were being studied to break the economic blockade set up by the United States, Great Britain and the Netherlands against Japan.
Preparations Against a Russian Invasion of Manchuria
The outbreak of war between Germany and the Soviet Union on 22 June 1941 was a matter of grave concern to Japan. Japan had signed a non-aggression pact with the Soviet Union and, since Germany had not consulted Japan prior to attacking the Soviet Union, it was not felt that Japan was morally bound to support Germany through the Tripartite Pact. Fears, however, were entertained that the Soviets might now invade Manchuria. In order to guard against such an eventuality, it was planned to reinforce the Japanese forces in that area immediately.
In June 1941, the Kwantung Army had 12 divisions, plus the 1st and 2d Tank Brigades and the 2d and 5th Air Groups disposed in Manchuria.4 The ground units were incorporated into the 3d through 6th Armies with the exception of the 10th, 28th and 29th Divisions, which were assigned directly to the command of the Kwantung Army commander. In July, the Army General Staff planned to increase the strength of the Kwantung Army by fall. The 51st and 57th Divisions, therefore, were organized in Japan and dispatched to the Kwantung Army. In addition, in order to strengthen the internal defense of Manchuria, the Kwantung Defense Army, composed of five independent garrison units, was organized. Further, such units as field heavy
artillery, antiaircraft, independent antitank, antiaircraft machine gun, independent engineer, signal and railway units were to be strengthened and logistic units such as motor transport, draught and pack horse, service, medical and veterinary units were to be reinforced.
So as to make this reinforcement of forces (which was the largest ever attempted by the Imperial Japanese Army) appear to be merely a large-scale exercise, the Army General Staff referred to it as the "100th Preparation" and the Kwantung Army as the "Special Maneuver of the Kwantung Army."
Through this mobilization, the strength of the Kwantung Army was increased to approximately 700,000 men, 140,000 horses and 600 airplanes. The strength of the Far Eastern Soviet Army at the time of the outbreak of the German-Soviet war was estimated to be in the vicinity of 30 divisions, 2,300 tanks and 1,700 airplanes, and even after the outbreak of war, this strength remained along the eastern front.
In Korea, additional personnel were assigned to the 19th Division and further local recruitment was planned. Some combat and signal units of the Northern Army were strengthened.
Preparations Against the Economic Blockade by the United States, Britain and the Netherlands
The outbreak of the German-Soviet war placed the United States in a very strong position both politically and strategically and caused that country to take a firmer stand against Japan's proposed advance into southern French Indo-China. On 26 July, the United States and Britain, and on the 28th, the Netherlands froze all Japanese funds in their countries in retaliation for the Japanese invasion of French Indo-China. (Actually, Japanese troops did not begin their occupation of southern French Indo-China until 28 July.) This put a stop to all trade between these countries and seriously affected Japan's very existence.
On 5 August, the Japanese Government instructed its Ambassador to the United States to submit a plan for local settlement of the French Indo-China situation and, on the 8th, to attempt to arrange a direct meeting between the President of the United States and the Premier of Japan. The United States flatly rejected both proposals. Attempts to reach a solution through diplomatic channels continued but without success. Japan had not only lost the means of obtaining liquid fuel indispensable to her existence, but the ABCD powers continued to tighten their encirclement of Japan in eastern Asia.
At the beginning of September, therefore, members of the Government and Imperial General Headquarters met at a liaison Conference to discuss national policy. The conference agreed that, should diplomatic negotiations then being conducted in Washington fail, the
only alternative was to go to war. To meet such an eventuality, preparations for war were to be completed by the end of October.
Defensive preparations made immediately after the outbreak of the Soviet-German war had centered in Manchuria but now emphasis was gradually shifted southward, although diplomatic negotiations continued. Should the negotiations succeed, the military preparations were to be called a maneuver.
Estimate of the Enemy Situation Prior to the Outbreak of War
Imperial General Headquarters' estimate of the strength and location of United States, British and Netherlands forces in the southern territories, made in September 1941, are shown on Charts Nos. 7, 8 and 9. The total enemy army strength in the Southern Area was judged to be in the vicinity of 380,000 troops and 700 planes, but it had rapidly increased by the end of the year.
As many of the islands in the Pacific were governed as colonies by the Allies, Imperial General Headquarters did not believe that a coordinated defense effort by the people of the governing countries and the natives of the islands was possible.
Although the air forces in Thailand and Burma were small, Japanese landings could be attacked with bombers and torpedo bombers from Malaya, under cover of the newly arrived Spitfires. In addition, the Netherlands Air Force would probably support the British Air Force from bases in Sumatra and Borneo. The United States Air
Chart No. 7a
Estimated Army Strength of the Enemy in the South
Territories \ Classification Unit Composition Number of Units Strength Total Strength Malaya Regular Army British Troops British 7 inf bns as the nucleus 11,000 61,000 to 71,000 Indian Troops British officers, Indian troops 30,000 to 35,000 Australian Troops Australians One div as the nucleus 20,000 to 25,000 Malayan Troops British officers, Malayan troops Unknown Volunteers Insufficiently trained and equipped 20,000 20,000 Burma British Troops British 2,000 35,000 plus Chinese troops Indian Troops British officers, Indian troops 1 inf brig as the nucleus 7,000 Burma Native Troops Poor quality 26 inf bns as the nucleus 26,000 Chinese Troops Unknown British-Borneo Regular Army Mainly Indian troops 1,000 3,500 Volunteers 2,500 Hong Kong Regular Army 13,500 19,000 Volunteers 5,500
Chart No. 7b
Estimated Army Strength of the Enemy in the South (Cont'd)
Territories \ Classification Unit Composition Number of Units Strength Total Strength Philippines Regular Army Half Americans
42,000 162,900 U. S. Marines Americans 900 National Defense Army Filipinos 120,000 Guam U. S. Marines Americans 300 1,800 Native Troops 1,500 Netherland Indies Inner Territory Troops Partly European 2 divs as the nucleus 50,000 70,000 Outer Territory Troops Partly European 15 inf bns 20,000 Total Regular Army 223,700 to 233,700 Total Strength 373,200 to 383,200 Remarks: a. In addition, there were approximately 500,000 troops in India, 350,000 in Australia, and 100,000 in New Zealand.
b. The Thailand Army was believed to total about 30,000.
c. Regular Armies were stationed in Malaya, British Borneo, Hong Kong and the Philippines; all of the troops in Burma and the Netherland-Indies were regulars as were the Marines in Guam and the Philippines.
Chart No. 8
Estimated Enemy Air Strength In the South
Area Airplanes Number of Squadrons Number of Planes Total Planes Malaya Bombers 4 48 186 Fighters 4 48 Reconnaissance Planes 4 48 Seaplanes 3 18 Torpedo Bombers 2 24 Burma Bombers 1 approx 60 Fighters and Bombers 1 Pursuit Planes 2 Volunteer Army 1 Hong Kong Training Planes approx 10 Philippines Bombers 1 13 166 Pursuit Planes 3 75 Reconnaissance Planes 1 18 Sea Planes Patrol Bombers 2 30 Carrier Planes 30 Netherland Indies Array Planes Bombers 6 30 316 Fighters 7 130 Reconnaissance Planes 6 36 Sea Planes 120 Total approx 738 Remark In addition, there were believed to be approx 200 planes in India, 250 in Australia, and 100 in New Zealand, 180 in Thailand. Most of the planes in Thailand were training or transport planes.
Chart No. 9
Estimated Enemy Naval Forces Operating to the South
Country Location Battle Ships Aircraft Carriers Cruisers Destroyers Submarines Others Britain China & Philippines area 1 2 Hong Kong 3 53 Singapore 2 4 56 24 Colombo area 9 2 13 Bombay area 2 9 Eastern Africa 1 1 5 Aden & Red Sea area 2 3 1 Australian area 5 19 New Zealand area 11 East of Hawaii 1 1 Mediterranean Sea 5 4 15 55 20 2 America China & Philippines area 4 2 14 17 26 Hawaii area 7 7 18 46 28 43 Netherland Netherland Indies 5 8 19 56 Total 16 16 67 189 84 259
Corps in the Philippines was known to have only a few bombers and to be composed mostly of obsolete type planes.
The strength of the Far Eastern Soviet Army was estimated to be approximately 20 divisions, 1,300 tanks and 1,500 planes but, with the Germans attacking the Soviet Union on the western front, it was felt that much of this strength would be transferred to that front. If the Southern Operations were undertaken, however, it was recognized Japan must be prepared to withstand the united actions of the United States, Britain and the Soviet Union. The Soviet Union might begin an offensive action against Japan or the United States might advance a force (especially an air force) to the Far Eastern Soviet territory.
Outline of Plan for War
Immediately after the Tojo Cabinet came into power, on 23 October a Liaison Conference initiated studies of international conditions, in particular in regard to objectives, methods and possibilities of success in waging war against the United States, Great Britain, the Netherlands and China simultaneously.
After many conferences, finally on 5 November an Imperial Conference proclaimed "Japan, at this juncture, is resolved to wage war against the United States, Great Britain and the Netherlands in order to insure self-preservation and to establish a new order in Greater East Asia." Prime Minister Tojo then ordered a study
to be made of plane which would bring a possible war to a successful conclusion. A draft plan was submitted and agreed upon at the 15 November liaison Conference. It was known as "Outline of War Guidance Against the United States, Great Britain and the Netherlands." Its main points were:
By carrying out a speedy armed offensive, Japan will capture United States, British and Dutch strongholds in east Asia and the southwest Pacific and establish a strategically superior position.
By firmly securing the southern vital resources areas and the main lines of communications, Japan will establish a structure that will make her self-sufficient for an extended period of time.
Every effort will be made to draw out the main strength of the United States Navy at an appropriate time and destroy it in a decisive battle.
First, Japan will cooperate with Germany and Italy to force Great Britain to surrender. To do this Japan will sever the lines of communication between Great Britain, Australia and India and, by political maneuvers and destruction of trade, endeavor to incite discord between these countries. At the same time, Japan will instigate independence movements in Burma and India. Germany and Italy will be required to conduct operations in the Near East, North Africa and Suez, to strengthen the blockade against Great Britain and, if circumstances permit, to conduct landing operations against Great Britain.
Japan, Germany and Italy will strive to maintain contact and cooperate with one another through the Indian Ocean and will intensify surface operations.
Japan will further intensify her military and political strategy to subjugate Chiang Kai-shek's regime in China by exploiting the results of operations against the United States, Great Britain and the Netherlands, thus halting the flow of aid to Chiang and destroying China's fighting power; by seizing foreign concessions in China; by befriending and guiding the Chinese residents in the South Seas area and intensifying operations against China.
Every effort will be made to prevent the outbreak of war with the Soviet Union during the operations in the Southern Area.
An agreement will be made with Germany and Italy not to initiate a separate peace with the United States and Britain. Peace will not be made with Great Britain immediately after her surrender but rather Great Britain will be used to force the United States to sue for peace, thus ending the war.
At all times studies will be made of changes in battle trends, the international situation and public sentiment of enemy nations. In this way, efforts will be made to end the war at the following times:
- Termination of main operations in the Southern Area.
- Termination of main operations in China, particularly the submission of Chiang Kai-shek's regime.
- Favorable changes in the war situation in Europe, particularly the downfall of Great Britain; termination of the German-Soviet war or the success of Japan's policy for India.
Development of the Southern Operations Plan
A troop movement plan was now established to prepare for war to the south. Units were to be transferred gradually to central and southern China, Formosa and French Indo-China from Manchuria, Korea and from forces organized in Japan.
The units to be sent to southern China were to include the 51st Division from Manchuria; air service units, mainly from Manchuria; one tank regiment and six independent antitank gun companies from Japan and some signal and line of communications units from Japan and Manchuria.
Units for Formosa were to include the 3d Tank Brigade (which would include two tank regiments - one from Manchuria and the other, plus headquarters personnel, from Japan); four independent antitank gun companies from Japan; air units, mainly from Manchuria and some artillery, signal and line of communications units from Japan and Manchuria.
Units to be sent to northern French Indo-China were to include the 4th Independent Mixed Regiment from Japan; air service units, mainly from Manchuria and some line of communications units from Japan and Manchuria.
Air and sea navigation installations were to be established in Formosa, Palau, French Indo-China and southern China.
The completion of bases for line of communications units and the stockpiling of operational supplies and munitions in southern
China, Formosa and French Indo-China were to be speeded up. Fittings and armament for requisitioned ships were to be stockpiled. Homeland land defense areas and the national air defense were to be strengthened.
These measures had all been initiated prior to the end of October and Imperial General Headquarters now instructed the Army and Navy to complete them by the beginning of December. Accordingly the Army prepared and issued the orders of battle and preliminary orders for those units it planned to use in the Southern Operations.
Orders of Battle for the Southern Operations
As mentioned previously, in accordance with the decision of the Imperial Conference of 6 September 1941, the Army had begun to move troops, materials and munitions to be used in the Southern Operations to French Indo-China, Hainan Island, south China, Formosa, Amami Oshima, Palau and Bonin Islands. Then, on 6 November, Imperial General Headquarters issued the orders of battle for those units which were to participate in the Southern Operations. They were:
Southern Army Commander in Chief: General Count Juichi Terauchi
Southern Army General Headquarters
14th Army (16th Division, 48th Division, 65th Brigade)
15th Army (33d Division, 55th Division)
16th Army (2d Division, 56th Mixed Infantry Brigade)
25th Army (Imperial Guard Division, 5th Division, 18th Division)
3d Air Group (4 Fighter Regiments, 3 Light Bomber Regiments, 3 Heavy Bomber Regiments and 1 Reconnaissance Regiment)
5th Air Group (2 Fighter Regiments, 3 Light Bomber Regiments, 2 Heavy Bomber Regiments)
21st Independent Air Unit
21st Independent Mixed Brigade
4th Independent Mixed Regiment
2d Independent Engineer Company
3d Rail Transportation Department
2d Field Military Police Headquarters
South Seas Detachment:
South Seas Detachment and 55th Infantry Group
Commander: Maj. Gen. Tomitaro Horii
55th Infantry Group Headquarters
44th Infantry Regiment
One battalion, 55th Mountain Artillery Regiment
One company, 15th Engineer Regiment
In addition, the necessary number of shipping units, commanded by the Central Shipping Transport Headquarters under the Chief of the Army General Staff, were assigned to the Southern Army and the South Seas Detachment.
The 38th Division, commanded by the 23d Army commander, was assigned to the China Expeditionary Army, with the mission of capturing Hong Kong.
On 27 November, the 56th Division was transferred from the Western Army Command to the 25th Army. After the completion of the Hong Kong and Philippines Operations, the 38th Division of the 23d Army and the 48th Division of the 14th Army were to be transferred to the 16th Army to be used in operations against the Dutch East Indies.
Missions and Objectives Assigned
On 5 November, the Imperial General Headquarters Navy Section issued Navy Order No. 1 to the Combined Fleet, concerning the execution of operational preparations against the United States, Great Britain and the Netherlands. The order read:
In view of the great possibility of being compelled to go to war against the United States, Great Britain and the Netherlands in the cause of self existence and self defense, Japan has decided to complete various operational preparations within the first ten days of December.
The Commander in Chief of the Combined Fleet will make the necessary operational preparations.
Details of the operation will be indicated by the Chief of the Naval General Staff.
On the same day, the Chief of the Naval General Staff published directives supplementing this order. Accordingly, the Combined Fleet commander ordered the "First war Preparations" and in conformity with a prearranged task organization, all units to be committed to the operation took their positions in readiness for action. Their assigned sea areas were generally within the confines of the Homeland waters, Inner South Seas, Formosa and Hainan Island.
Earlier, the task force that was to make the surprise attack on Hawaii left for Hitokappu Bay and the submarine force headed for the Hawaiian Sea area, either directly or by way of the Marshall Islands.
Simultaneously with the issuance of the orders of battle, on 6 November 1941, Imperial General Headquarters dispatched orders to the Southern Army, South Seas Detachment and the China Expeditionary Army defining their missions should the negotiations between Japan and the United States fail.
Imperial General Headquarters Army Order No. 556 read:
Imperial General Headquarters shall prepare for the seizure of important areas to the south.
The Commander in Chief of the Southern Array, in conjunction with the Navy, shall assemble his main force in Indo-China, south China, Formosa, the Southwest Islands and the South Seas Islands and prepare to seize important areas to the south.
Separate orders will be issued for offensive operations.
The Commander in Chief of the Southern Army shall blockade China,
Should the Southern Army be attacked by troops of the United States, Great Britain or the Netherlands, the Commander in Chief shall counterattack immediately, while at the same time endeavoring to localize the incident.
The Commander in Chief of the China Expeditionary Army, the Commander in Chief of the General Defense Command and the Commander of the Formosa Army shall support the strategic preparations of the Commander in Chief of the Southern Army.
At the same time, Imperial General Headquarters Directive No. 991 was issued. It stated that the Commander in Chief of the Southern Army would complete operational preparations about the end of November, while making every effort to maintain friendly relations with French Indo-China and Thailand. It particularly stressed that every precaution would be taken to conceal the objectives of these operations.
Imperial General Headquarters Army Order No. 557 stated:
1. The Commander in Chief of the China Expeditionary Forces, in cooperation with the Navy, will prepare to occupy Hong Kong with a force organized around the 38th Division under the command of the 23d Army commander.
2. Detailed directives will be issued by the Chief of the General Staff.
Imperial General Headquarters Army Order No. 558 was transmitted to the South Seas Detachment commander through the Commander in
Chief of the China Expeditionary Army and read:
1. Imperial General Headquarters will prepare to occupy strategic areas in the south.
2. The South Seas Detachment commander, in. cooperation with the Navy, will advance his forces to the Ogasawara Islands and there prepare to occupy Guam. Separate orders will be issued for offensive operations.
3. In the event the South Seas Detachment is attacked by the American-British-Dutch forces, or by any one of these forces, the commander is authorized to intercept the attack. In this event, efforts will be made to settle the matter locally.
4. The Commander in Chief of the General Defense Command and the 55th Depot Division commander will assist in the operational preparations set forth in paragraph 2.
5. Detailed directives will be issued by the Chief of the General Staff.
On 15 November, the Army General Staff issued Imperial General Headquarters Order No. 564 to the Southern Army concerning the occupation of strategic areas:
Imperial General Headquarters plans to occupy the strategic areas in the south to insure the existence and self-defense of Japan, as well as to establish a new order in Greater East Asia.
The Commander in Chief of the Southern Army, in cooperation with the Navy, will seize important areas to the south.
A separate order will be issued announcing the date on which to open the attack.
The areas to be occupied are the Philippines, British Malaya, the Dutch East Indies and part of Burma.
In carrying out these operations, the Commander in Chief of the Southern Army will endeavor to insure stability in Thailand and French Indo-China and blockade China. If military forces in Thailand or French Indo-China offer resistance, the Commander in Chief of the Southern. Army is authorized to occupy strategic areas in these countries.
Military government will be established in occupied areas in order to restore public peace, obtain important national defense resources and insure self-sustenance of the forces.
The Commander in Chief of the China Expeditionary Army, the Commander in Chief of the General Defense Command and the Formosa Army commander will render necessary assistance to the operations to be carried out by the Commander in Chief of the Southern Army.
Detailed directives will be issued by the Chief of the General Staff.
At this time, Imperial General Headquarters was awaiting the outcome of negotiations still being held in Washington but felt that the Southern Army should be prepared to move should the results prove unfavorable. On 20 November, therefore, in compliance with Imperial General Headquarters orders, the Commander in Chief of the Southern Army issued instructions to the armies under his command in regard to the occupation of the Southern area.
Overall Operations Plan of the Imperial Japanese Army
The objectives of the operation were the destruction of the principal bases of operation of the United States, Great Britain and the Netherlands and the seizure and occupation of strategic areas in the south.
The areas to be occupied were the Philippines, Guam, Hong Kong, British Malaya, Burma, Java, Sumatra, Borneo, Celebes, Bismarck Archipelago and Dutch Timor.
The operation was to commence with the Army, in close cooperation with the Navy, launching attacks.
Operations were to be launched against the Philippines and British Malaya simultaneously in closely coordinated actions by the Army and Navy. These areas were to be occupied in the shortest possible time. The operations were to open with an air raid against the Philippines and the landing of an advance force on Malaya. The main forces of the designated armies were then to land in the Philippines and British Malaya and capture enemy positions as quickly as possible. In addition, the strategic areas of Guam, Hong Kong and British Borneo were to be occupied during the initial stage. Thailand and French Indo-China were to be neutralized.
After enemy positions in Dutch Borneo, the Bismarck Archipelago and the Celebes had been seized, and during the progress of the Malaya Campaign, south Sumatra was to be occupied. While south Sumatra, rich in natural resources, was being secured, preparations were to be made for the occupation of Java. Strategic positions in the Moluccas and Timor were to be occupied. The enemy air force on Java was to be destroyed and Java occupied. After the occupation of Singapore, at an opportune time, strategic positions on northern Sumatra were to be occupied.
Even if the Combined Fleet were compelled to conduct operations against the United States Fleet or if the Soviet Union should enter the war, the operations against the Philippines and Malaya were to be continued and the above objectives achieved as quickly as possible.
While these operations were in progress, at an opportune time, enemy air bases in southern Burma were to be captured. Occupied areas were then to be secured and mopping-up operations conducted in Burma.
An order was to be issued later stating the exact day and time of the opening of hostilities, with a rider added stating that should the Japanese-American negotiations be successfully concluded, the operations were to be suspended.
The strength to be used consisted of eleven divisions, nine tank regiments, two air groups and other units directly assigned to the Southern Army. An outline of the tactical grouping of the Army and the assigned operational areas was as follows:
Troops under direct control of the Southern Army One division, one mixed brigade and two air groups stationed in French Indo-China. 25th Army Four divisions for the Malaya Operation. Air support to be provided by the 3d Air Group. 16th Army At first - one division for operations in the Dutch East Indies. Two more divisions were to be transferred to the 16th Army upon completion of other operations.
15th Army Two divisions for operations in Thailand and Burma. 14th Army Two divisions for operations in the Philippines. Air support was to be provided by the 5th Air Group. South Seas Detachment (under direct control of Imperial General Headquarters.) Three infantry battalions for operations on Guam and the Bismarck Archipelago. 23d Army (under the command of the China Expeditionary Army.) One division for operations in the Hong Kong area.
Plans for the Capture of Hong Kong, Guam and the Bismarck Archipelago
Immediately upon receiving confirmation of the landings on Malaya, Japanese Army and Navy air units were to strike Hong Kong and its environs. Enemy air power was to be neutralized and all important military installations, as well as vessels in the harbor, were to be destroyed. Timing the action with the progress of the air attack, powerful units from the 23d Army were to cross the border near Shenchuanhsu and occupy Kowloon. Immediately after the capture of Kowloon Peninsula, the invasion force, in close cooperation with the Navy, was to attack and capture Hong Kong.
To eliminate a potential enemy menace against the South Pacific islands, it was planned that the South Seas Detachment, in cooperation with the 4th Fleet, would occupy Guam and capture the air bases
in the Bismarck Archipelago. A naval land combat team would then relieve the Detachment and the Detachment, cooperating with a naval force, would occupy Rabaul at the earliest opportunity and establish air bases on Hew Britain. Defense of this area would then be turned over to a naval land combat unit and the South Seas Detachment would return to Palau.
Air Force Operational Assignments
At the outbreak of war, the Army and Navy Air Forces jointly were to attack enemy air bases. They were to establish air superiority and support the Army first in landing operations and later in land actions. The Army Air Force would operate mainly in the Malaya area. Air bases were to be established in southern Formosa for the Philippines Campaign and in southern French Indo-China for the Malayan Campaign.
The Army Air Force was to be responsible for air cover during the landing on Malaya. In order to make the movement of the landing force easier, on the day of the landing, air attacks were to begin at dawn and the main enemy air bases were to be destroyed during the first attack. After the landing, a forward air base was to be established quickly for close support of land operations.
Lines of Communications (Logistical Support)
Southern French Indo-China was designated the main supply base for the over-all Southern Operations with Formosa as an intermediate base and Canton as an auxiliary base.
Line of communications troops were to be composed mainly of troops redeployed from Manchuria. Troops stationed in China were to be held in reserve.
In order to pour most of the nation's fighting strength into the Southern Operations, operational materials in Japan and Manchuria were allocated to the Southern Operations. It was planned that initially sufficient supplies and matériel for one campaign would be shipped simultaneously with the landing forces.
Instructions were issued to the China Expeditionary Army to intensify the self-sustenance program.
China Expeditionary Army Operational Assignments
In China, the Army and Navy, in general, were to maintain their present dispositions. In addition, they were to eradicate the influence exerted by America and Britain in China. Both military and political pressure were to be used to destroy the Chungking Government. If, after the start of the Southern Operations, the Soviet Union were to enter the war in the north, the necessary troops were to be redeployed to Manchuria by both land and sea. At the same time, part of the occupied area in the Wuchang-Hankou district and north China would be reorganized and the necessary areas secured to prevent any rise in enemy power.
If the Soviet Union should join the United States, or if the Soviet Army independently should move against the Imperial Japanese
Army, the necessary army groups from China and Japan were to be transferred immediately to meet the challenge. The Soviet Par East air strength was to be destroyed. The enemy in the Ussuri area was to be attacked at once and key positions in the area occupied.
Proposed Southern Operation Military Administration
Military administration was to be set up in occupied areas and the armies located in these areas were to be held responsible for the successful functioning of the system. Methods and policy were to be developed for the purpose of restoring public order, the rapid control of important resources vital to defense and the self-sustenance of the Army.
In enforcing a military administration, existing administrative organizations were to be used to the fullest extent and local systems and racial customs were to be respected.
The occupation forces were to aid in the development of vital defense resources insofar as the operations permitted. Key defense resources developed or acquired in the occupied areas were to be included in the Materials Mobilization Plan of Imperial General Headquarters and those required for local self-sustenance of the operational forces were, as a rule, to be allocated on the spot.
The nationals of America, Britain and the Netherlands were to be directed to cooperate with the military administration. Proper
steps, to include deportation, would be taken against those who did not comply. The rights and interests of Axis Powers nationals were to be respected but any increase in their number was to be restricted. Chinese merchants residing in occupied territories would be required to comply with Japanese policies and to break their ties with the Chungking Government. The occupation forces were to endeavor to gain the confidence of the nationals of the occupied areas so as to prevent the launching of untimely independence movements. Japanese civilians desiring, to go to the occupied areas were to be carefully screened and preference was to be given to those who had lived there prior to the commencement of the operations.
Division of responsibility between the Army and Navy in military administration of the occupied areas was to be decided by the respective departments in Imperial General Headquarters. The territories for which the Army was to be held responsible (with assistance being given by the Navy) were Hong Kong, the Philippines, British Malaya, Sumatra, Java, British Borneo and Burma. The Navy (with the Army assisting) was to be responsible for Dutch Borneo, Celebes, Moluccas, Lesser Sunda Islands, New Guinea, Bismarck Archipelago and Guam.
First Phase of the War
Part 1 (December 1941 - June 1942)
Decision to Go to War
On the afternoon of 1 December 1941, an Imperial Conference was held in the presence of the Emperor at the Imperial Palace when it was decided that: "Matters have now reached the point where Japan, in order to preserve her Empire, must open hostilities against the United States, Great Britain and the Netherlands."5
Prior to this, at the Liaison Conference held from 23 to 30 October 1941, it had been decided that, should war prove inevitable, hostilities would begin "during early December at the latest."6 On 5 November, this decision was confirmed by the Imperial Conference. Accordingly, Imperial General Headquarters issued orders and directives to the Commander in Chief of the Combined Fleet and the Commanding General of the Southern Army to complete operational preparations for war against the south within the first ten days of December. At all times it was emphasized that war would be resorted to only should the negotiations then being conducted in Washington
fail. Having little hope for the success of the Washington negotiations, the members of the Imperial Conference advanced the following reasons for opening hostilities at the earliest possible date:
The Navy High Command felt that by March 1942 the United States Navy strength would be built up to such a degree that it would place the far smaller Japanese Navy at a tremendous disadvantage.
Japan could not hope to keep pace with the United States in an armament race.
Critical fuel stockpiles were being depleted from day to day and, unless this fuel could be replaced by procurement from the south, it was estimated that after March 1942 even the fuel demands for the first phase military operations could not be met.
If the war were delayed until spring, Japan might be committed to a war on two fronts as the USSR might launch an attack from the north.
Delay in opening hostilities would give the United States, Britain, the Netherlands and China further opportunities to build up their combined defensive power in the southern area.
Weather conditions in the anticipated theater of operations would be an important factor. While January and February were unsatisfactory months for landing operations on the Malay Peninsula because bad weather could normally be expected during those months, the tide and weather forecasts for the first week in December were considered favorable. In addition, during the first week in December, carriers could approach Pearl Harbor under cover of darkness and the moon would rise about 0300 hours at which time the planes would attack.
In the light of the above, 8 December was considered to be the last favorable date on which to launch the initial attack. At the close of the Imperial Conference of 1 December, therefore, on the same day the Chief of the Army General Staff issued orders to the Southern Army and China Expeditionary Army commanders, which summarized stated:7
Orders to the Commander in Chief of the Southern Army
Japan has decided to wage war against the United States, Great Britain and the Netherlands.
The CinC of the Southern Army will launch offensive (invasion) operations on X-Day December, and immediately occupy strategic areas in the Philippines, British Malaya and the Netherlands East Indies.8
Should the enemy attack Japanese forces prior to the designated day for opening hostilities, the CinC of the Southern Army is authorized to launch his offensive, in cooperation with the Navy, at an opportune time.
Should British forces enter Thailand, the CinC of the Southern Army, in cooperation with
the Navy, will invade Thailand at an opportune time.
Should enemy aircraft make repeated reconnaissance of important Japanese bases or convoys, the CinC of the Southern Army will order them shot down.
The South Seas Detachment commander, immediately after X-Day, will invade Guam. After capturing the island, the commander will assemble his strength on Palau and there prepare for operations against Rabaul.
Orders to the Commander in Chief of the China Expeditionary Army
The CinC of the China Expeditionary Army, in cooperation with the Navy, will occupy Hong Kong with a force organized around the 38th Division, commanded by the 23d Army commander. Operations will be launched immediately after the Southern Army's landings on or air raids upon Malaya are confirmed. After Hong Kong is occupied and the neighboring areas secured, a military government will be established.
Should the enemy initiate attacks prior to X-Day, the CinC of the China Expeditionary Army is authorized to intercept these attacks at an opportune time.
Should enemy aircraft carry out repeated reconnaissance of military movements, the CinC of the China Expeditionary Army will order them shot down.
The CinC of the China Expeditionary Army will take possession, if necessary by force, of the British Concession in Tienching, the International Settlement in Shanghai and all other enemy interests in China.
Orders to the CinC, China Expeditionary Army and the Commander, Kwantung Army in Regard to the China Incident
On 3 December, the Chief of the Army General Staff issued orders to the Commander in Chief of the China Expeditionary Army and the Commander of the Kwantung Army in regard to the China Incident. The CinC of the China Expeditionary Army was ordered to strengthen the blockade against the enemy and to destroy the enemy's will to fight a prolonged war. In addition, he was to use every endeavor to bring the China Incident to an end. The Commander of the Kwantung Army was charged with the defense of Manchuria. He was ordered to attempt to localize border clashes and, if possible, to avoid open war with Russia.
Summary of Operational Progress During 1st Phase
On 8 December 1941, Japanese sea and air forces launched surprise attacks on the United States Fleet in Pearl Harbor and the main airport on Hawaii. By this spectacular stroke Japan rendered the United States Fleet incapable of effective counterattack during the initial invasion operations.
Japan felt that any diplomatic move toward an alliance with Thailand prior to the outbreak of hostilities might reveal Japan's intention to go to war. It was decided, therefore, to effect a sudden occupation of Bangkok, capital of Thailand, simultaneously with the opening of hostilities in the Pacific. On 6 December, elements of the Guards Division left Phuquoc Island and, on the morning
of the 8th, landed near Bangkok. At 0300 on the 8th, the main body of the Division crossed the French Indo-China - Thailand border from the direction of Phnom Penh. Both forces advanced swiftly toward Bangkok, encountering very little resistance. By evening of 8 December the capital. was occupied.
British and Japanese influence was believed to be equally strong in Thailand before the opening of hostilities but the course of events compelled Prime Minister Phibun to yield to Japan's demands and, on 11 December, the Japanese Ambassador presented the Thai Prime Minister with a draft of a Japanese-Thailand Military Alliance Agreement. After the necessary procedures, the treaty pledging mutual support was formally signed at Bangkok on 21 December.9
In Malaya, on 8 December, the 25th Army made surprise landings at Singora, Patani and Thepha and, although there were some local skirmishes, by noon the towns and airfields were occupied.10 Later in the day successful landings were made at Bandon, Nakhon, Chumphon and Prachuap. In the Kota Bharu area, in spite of heavy casualties inflicted by enemy planes during the landings, 25th Army troops landed and began their advance to the south. The 25th Army moved rapidly
down the Malay Peninsula and, by 30 December, had occupied Kuantan. It continued to advance and, on 15 February 1942, less than two months after the outbreak of hostilities, Singapore and its famed naval base surrendered.
On 10 December, Japanese planes sank two British battleships, the Prince of Wales and the Repulse off the Malay coast, eliminating any immediate threat of interference to the move south from the British Fleet.11
About 20 January 1942, the 55th Division, under the command of the 15th Array, began to cross the Burma-Thailand border and, on the 30th, occupied Moulmein.
In the early hours of the morning of 8 December 1941, the 23d Army began the operation to take Hong Kong by bombing and destroying enemy planes on Kaitak airfield. The operation progressed much faster than anticipated and, by the 14th, the entire peninsula was occupied. The 23d Army decided to follow this up with an immediate attack against Hong Kong, thus denying the enemy an opportunity to regroup. For a time the enemy resisted stubbornly but they were gradually pushed back and, on 25 December the defenders surrendered.
In the Pacific area, Guam was occupied by the South Seas Detachment on 10 December and Wake on the 23d. On 23 January 1942, the Detachment landed at Rabaul and, within a few hours, had captured
the town. By 5 February, it had completed mopping-up operations of the surrounding area.
On 2 February 1942, Imperial General Headquarters ordered the commander of the South Seas Detachment, in cooperation with the Navy, to attack and capture strategic areas in British New Guinea and the Solomons as soon as possible. The Southern Army was ordered to capture the Andaman Islands and Timor.
In the Philippines, the Japanese Army and Navy air attacks on 8 December were successful and, on the 10th, the advance ground forces captured air bases on northern Luzon. On 22 December, the 14th Army landed the 48th Division at Lingayen Gulf and, on the 24th, the main force of the 16th Division landed at Lamon Bay. Although some resistance was encountered, it was soon overcome and Japanese forces occupied Manila on 2 January 1942. Some of the enemy, however, escaped to strongly fortified positions on Bataan Peninsula and Corregidor. The 14th Army ordered the 16th Division and 65th Brigade to attack these positions but they were unable to dislodge the enemy fighting a bitter defensive battle. As Imperial General Headquarters regarded the situation in the Philippines with the gravest concern, on 10 February, it ordered the 4th Division, then in Shanghai, to the Philippines. In addition, the Southern Army placed part of the 21st Division, then en route from French Indo-China, under the command of the 14th Army and diverted heavy artillery from Canton to
the Philippines. During March, the 14th Army was further reinforced. On 3 April, the attack on Bataan was renewed and, on the 9th, the peninsula fell. While continuing to mop up the surrounding area, the 14th Army then prepared to attack Corregidor, but it was not until 7 May that Corregidor was taken. At this time, all U.S. forces in the Philippines surrendered.
Plans for Java Operation
One of the main objectives of the Southern Operations was the oil-rich Netherlands East Indies. In late December, with the rapid advance of the Japanese forces, the commanders of the Southern Army and 2d Fleet strongly recommended that the operations against Sumatra and Borneo be speeded up and that the Java Operation be undertaken one month earlier than at first planned. They reasoned that this would prevent the Allies from regrouping and replenishing their forces. In addition, should the Soviet Army attack from the north in the spring, the occupation of Java would be completed and troops could be transferred to Manchuria.
Imperial General Headquarters promptly approved this recommendation and issued the necessary orders.
Southern Army issued orders to reinforce the 16th Army. On 4 January 1942, the 38th Division, which had previously been engaged in the Hong Kong Operation, was placed under the command of the 16th Army and its Ito Detachment ordered to seize Amboina. On 12 January,
the Detachment left Hong Kong and, on the 31st, invaded Amboina. By 7 February, the entire island was occupied. On the 17th and 18th, the Toho Detachment (Ito Detachment renamed) left Amboina and, by 20 February, its main force captured Koepang while other units landed and occupied Dili. During this movement the Detachment was protected by the 2d Destroyer Squadron.
On 14 January, the 48th Division, which had participated in the capture of Manila, was placed in the order of battle of the 16th Army. By early February, it had assembled at Jolo. Simultaneously, the 2d Division and units under the direct command of the 16th Army assembled at Camranh Bay.
On 16 December 1941, the Kawaguchi Detachment landed on British Borneo and, meeting very little resistance from the enemy, the same morning captured the oilfields at Seria and the oilfields and airfield at Miri. The operation progressed favorably and, by the end of January, the entire island had surrendered. Advancing southward by land and sea, on 10 February, the Sakaguchi Detachment captured Bandjermasin. About the same time, a Navy unit occupied Makassar.
One battalion of the Sakaguchi Detachment (known as the Kume Unit) was placed under the direct command of the 16th Army and ordered to remain and garrison Bandjermasin while the main body of the Detachment prepared for the invasion of Java. At this time, special efforts were made to speed up Air Force organization to protect convoys and to strengthen lines of communications.
On 15 February, the main force of the 38th Division, covered by the 3d Destroyer Squadron, sailed into Muntok. It crossed the Musi River and, on the 16th, landed and occupied Palembang. This was regarded as a very important victory as the 38th Division, in cooperation with the 1st Airborne Unit, succeeded in taking the Palembang oil refineries in perfect condition.
The 16th Army was now ready to launch its attack against Java. Coordinating their movements, the convoys converged on Java from east and west. The 3d Fleet was responsible for the convoy from the east and the First Southern Expeditionary Fleet for the convoy from the west. On 27 February, a reconnaissance plane from the 3d Fleet reported the enemy fleet advancing toward the convoy. Units of the 3d Fleet, therefore, contacted and attacked the enemy off Soerabaja, inflicting heavy casualties. Simultaneous with the sea battle off Soerabaja, another naval engagement was taking place near Batavia. On 1 March, the Australian cruiser Perth and the American cruiser Houston were sunk, in addition to two destroyers and one oiler sunk and one minesweeper disabled and beached.12
On 1 March, the 16th Army landed its forces on Java. Very little resistance was encountered during the landings. On the 5th, the 2d Division captured Batavia and, on the 7th, the 48th Division captured Soerabaja. On 9 March, with the surrender of the Dutch Army,
the Java Operation was completed.13
The Army General Staff was anxious to complete the conquest of Burma as quickly as possible because of its strategic value as a key point in the northern flank of the Southern Area. In addition, Burma would prove invaluable in a blockade against China. Japan's overall military strength, however, would not permit a full-scale Burma Operation at the same time as the opening Southern Operations. As the war had progressed far more favorably than had at first been anticipated, about mid-January, the Southern Army commander was ordered to proceed with the Burma Operation without waiting for the completion of the other Southern Operations. The Southern Army commander, in turn, ordered the 15th Army (composed mainly of the 33d and 55th Divisions) to undertake this mission.
Before the war, enemy strength in Burma was estimated to be somewhere in the vicinity of: Army - 39,000 men; Air Force, 60 planes, but indications were that the Allies were making every effort to increase their strength in this area.14 In addition, there were known to be approximately 10 Chinese divisions along the Burma-China border.
Reduced to a basic outline, orders for the Burma Operation issued by the Army General Staff to the Southern Army stated:
The objective of the Burma Operation is to defeat the British Army and to occupy and secure the main strategic points in Burma, In addition, the blockade against China will be strengthened.
The 15th Army will invade south Burma quickly and advance to the strategic line of the Sal-ween River near Moulmein. Here it will prepare for the next operation. The main force will then advance from the sector along the Moulmein-Pegu Road and quickly occupy strategic areas in central Burma.
On 17 February, the 15th Army commander decided first to take Rangoon and ordered the 33d and 55th Divisions to advance to the Sittang River to prepare for this operation. On 6 March, the Divisions began their advance and, on the 8th, without meeting much resistance, occupied Rangoon. After reinforcing its strength and replenishing its equipment the Army pushed forward. On 26 March, the 55th Division attacked Toungoo. On the 28th, the 56th Division (which had been placed in the order of battle of the 15th Army on 4 March) advanced to the vicinity of Toungoo. There it joined the 55th Division and, after bitter fighting, these two divisions finally occupied the town on the 30th. Also during March, the 33d Division attacked and captured Prome.
The 18th Division (which was placed in the order of battle of the 15th Army on 4 March) landed at Rangoon on 8 April. From there it proceeded to Toungoo to prepare for the next operation.
The 15th Army continued to advance and, by 29 April, had occupied Lashio and other strategic points along the China-Burma border. On 1 May, Mandalay was occupied. During the first part of May, the 15th Army advanced first to Bhamo and then to Myitkyina, in addition to occupying the airfield at Akyab.
During these operations, the 5th Air Group cooperated very closely with the 15th Army.
Heavy casualties were inflicted on the Chinese 5th, 6th and 66th Armies. The 6th Army retreated toward Cheli and Fohai while the 5th and 66th Armies retreated to the district north of the Burma-Kunming Road. The British Army, which also had suffered heavy casualties, retreated to India.
On 18 May, the Southern Army ordered the 15th Army to secure its occupied area.
Navy Operations in the Indian Ocean
The first of a series of operations in strategic areas along the outer perimeter was to be undertaken by the Navy against Ceylon.
By March 1942, combined Army and Navy forces had captured the southern part of Burma, the Andaman Islands, Nicobar Islands, Malaya and the Netherlands East Indies, but it was still felt necessary to defeat the British Fleet operating in the Indian Ocean, in order to secure the occupied areas. On 9 March, therefore, Admiral I. Yamamoto, Commander in Chief of the Combined Fleet, ordered Vice Admiral Nobutake Kondo, commander of the Southern Force, to destroy the enemy
forces around Ceylon in a surprise raid and to effectively cover the sea transportation of ground forces to Burma. On the 14th, Vice Admiral Kondo issued the necessary orders to his force. On 26 March, part of the Southern Force, under the command of Vice Admiral Nagumo, left Starling Bay in the Celebes and, by 5 April, had reached a point south of Ceylon, from where it launched an air attack against Colombo. Despite fierce enemy fighter opposition, approximately 50 enemy aircraft were shot down, some 10 merchant ships in the harbor were sunk or damaged and an enemy airfield was demolished. In addition, two British heavy cruisers, the Dorsetshire and the Cornwall, were sunk 280 nautical miles south southwest of Colombo. Vice Admiral Nagumo then decided to strike Trincomalee. He arrived at a point east of the island on 9 April and subjected Trincomalee to an air attack for about one hour. Approximately 40 enemy aircraft were shot down, one light cruiser and three merchant vessels were sunk and the naval port and airfield were demolished. On the same day, an aircraft carrier of the Hermes class was intercepted and sent to the bottom southeast of Trincomalee.
The 2d Submarine Squadron patrolled the waters west of Ceylon and in the Bombay area, from 1 to 10 April, sinking or damaging nine enemy freighters. The Malay Force, operating in the northern part of the Bay of Bengal, sank or damaged some 30 enemy vessels.
During this period the Southern Force operated in the waters around Andaman Islands, supporting friendly forces.
These operations enabled the Navy to maintain control of the eastern part of the Indian Ocean for some time.
Coral Sea Battle
Imperial General Headquarters was keenly aware of the strategic importance of Port Moresby, an Australian air and naval base on the southeastern part of New Guinea, and in late January 1942, just after the occupation of Rabaul, it was decided to capture Port Moresby. On 2 February 1942, Imperial General Headquarters ordered that after the capture of Lae and Salamaua in New Guinea, if the situation permitted, Moresby was to be taken. The 4th Fleet at that time had no available aircraft carriers and the plan had to be postponed. Later, with the successful progress of the Southern Operations, the Combined Fleet dispatched the necessary carriers. On 18 April, therefore, Imperial General Headquarters ordered the South Seas Detachment to put
into action the long-planned invasion, giving 10 May as an approximate date for the landing.15
In the latter part of March, the Commander in Chief of the 4th Fleet ordered the 19th Minelaying Division to occupy Tulagi and establish a seaplane base at Cavutu Islands by 3 May, in preparation for the invasion of Port Moresby.
After the capture of Lae and Salamau, the South Seas Detachment,
in coordination with the 4th Fleet, prepared to attack Port Moresby, The Detachment planned to carry out a sea-borne invasion and, escorted by a naval force under the command of the 4th Fleet, on 4 May left Rabaul. On the same day, an enemy carrier task force made heavy raids on Tulagi.
On the morning of the 7th, as the convoy was approaching Misima Island in the Louisiade Archipelago, a powerful enemy carrier task force intercepted it in the Coral Sea, A fierce air-sea battle raged through the 7th and 8th. Although heavy damage was inflicted on the enemy, the convoy too suffered heavy casualties. On the evening of the 9th, therefore, the convoy returned to Rabaul and the Port Moresby Operation was suspended.
Although the Coral Sea Battle was a tactical victory for the Japanese, since the enemy suffered relatively heavier losses, strategically it was a victory for the Allies, as the main purpose of the operation, the capture of Port Moresby, was thwarted.
Situation Review and Tentative Plans
By mid-March, with the successful progress of the Southern Operations, the occupation of the desired areas appeared to be in sight. It was anticipated, however, that the Allies would counterattack from the east and west. Imperial General Headquarters, therefore, prepared a new tentative plan of operations.
With the completion of the Southern Operations, the forces were to be consolidated and regrouped, and military administration was to
be established in the occupied areas to restore order and promote friendly relations with the natives. Efforts were to be made to occupy the main strategic areas of central Burma by destroying the enemy, particularly the Chungking Army. At the same time, the American and British forces were to be kept on the defensive by diversionary operations around the perimeter of the main occupied areas. Every effort was to be made to end the China Incident by both strategic and political methods.
The national defense program was to be enlarged and, where necessary, additional units were to be organized.
It was planned to continue to strengthen the Russian border while, at the same time, every attempt was to be made to maintain the current state of relations with Russia.
Great importance was placed on the organization and maintenance of a reserve force to be used for any emergency. In addition, plans were to be drawn up in regard to the direction of diversionary operations outside the defense perimeter.
These tentative plans, prepared in mid-March, were a guide throughout the following months and energetic efforts were made, particularly by the Southern Army, to put them into effect.
By late May, restoration of peace and order in the occupied areas and the establishment of a military administration appeared to be progressing smoothly. With the exception of disturbances by
some enemy remnants in the Philippines, Burma and Malaya, all was quiet in the occupied areas.
The Army General Staff concentrated on stabilizing the occupied areas and ordered the Southern Army to set up a system whereby it could maintain itself without assistance from the Homeland. It continued to strengthen the defenses of Japan by training and reorganizing its units and by securing the areas in the south from which important resources were being obtained.
Members of Imperial General Headquarters believed that if the Chinese forces in central China and the British forces in Burma could be defeated, now that the British in Malaya and Singapore had been overcome, the United States forces could be discouraged from continuing the war. Plans, therefore, were drawn up with this concept in mind. In addition, plans for possible countermeasures against a potential attack by Russia were necessary. Under these circumstances, it was essential that plans be flexible, in order to meet any eventuality.
It was decided, after determining the number of troops to be stationed in the Southern Area and perimeter territories, that the main body of the other units would be returned or transferred to Japan, while some units would be transferred to Manchuria and China. The divisions at first planned to be withdrawn from the line were the Guards Division and the 2d, 4th and 5th Divisions to be transferred to Japan; the 33d Division to be sent to China and the 16th
Division to Manchuria. Due to increased enemy activities, however, the only division actually transferred was the 4th Division, together with a few units under the direct control of the Southern Army.
The 14th Army was placed under the direct control of Imperial General Headquarters. This was done in order to relieve the Southern Army of some of its heavy burden of responsibility and to aid in the effective military administration in the Philippines. The 14th Army commander was ordered to cooperate with the Navy in maintaining order and to speed up the establishment of military administration in the Philippines.
The Kwantung Army was ordered to demobilize part of its strength, especially the older soldiers, within the limits assuring effective defensive and operational preparations in Manchuria.
As part of a plan to enlarge Japan's armored strength, the Kwantung Army was directed to organize the 1st and 2d Tank Divisions while the China Expeditionary Army was to organize the 3d Tank Division. First and Second Area Army Headquarters, Mechanized Army Headquarters and 2d Army Headquarters were to be established to strengthen the command system of the Kwantung Army. These headquarters were established in July 1942.16
It was planned to demobilize the 52d Division in Japan but due to increased enemy activity during May and June this was not possible.
The 3d Air Army was to be established in the Southern Area with a strength of approximately five air brigades. It was to be charged with carrying out offensive air operations in India and China and with the air defense of strategic areas in Sumatra and Java.
One air division headquarters, with the necessary units, was to be transferred to the China area from the south after the 3d Air Army Headquarters was established. Two air divisions were to be placed under the command of the 2d Air Army commander to strengthen the Manchuria area. These changes in organization meant that some of the Southern Area air units were to be transferred to Manchuria.
After completion of the first phase of the Southern Operations it was planned to harass the enemy from such strategic points along the perimeter as the Aleutians, Fiji, Samoa, New Caledonia, eastern New Guinea, Coco Islands, eastern India, and Ceylon. Ceylon was to be neutralized.
In May 1942, Imperial General Headquarters prepared an estimate on the current and potential enemy strength throughout the world (Charts Nos. 10 and 11).
Preliminary Planning for the Chungking Operation
In the spring of 1942, as the war was progressing favorably, Imperial General Headquarters decided to investigate the possibility of a large scale attack against the Chinese Central Army in Szechuan Province to destroy the Chungking Government's bases of resistance. It was estimated that, if the operation were successful,
Chart No. 10a
Estimate of the Enemy Strength, May 1942
Area \ Distribution Ground Strength Air Strength Remarks United States 1,800,000 men (43 divisions completed) 3,500 active front-line planes Estimated strength end of 1942: 2,000,000 men and 6,000 planes Panama Area Army 45,000 men 450 planes Alaska & the Aleutians Army & Navy 8,800 men 150 planes Hawaiian Islands Army 35,000 men 400 planes Midway Army & Navy 1,700 men 50 planes Samoa U.S. Navy 750 men 20 planes Fiji U.S. & British 7,000 men 20 planes New Caledonia U.S. & Free French Govt 3,000 men 10 planes Australia 350,000 men (10 divisions) 500 planes Number of U.S. troops in Australia and New Zealand: 2-5 divisions. Powerful units in Southwest New Guinea & Northern Australia
Chart No. 10b
Estimate of the Enemy Strength, May 1942 (Cont'd)
Area \ Distribution Ground Strength Air Strength Remarks New Zealand 70,000 men (3 divisions) 250 planes Iceland & Northern Ireland U.S. Troops (1-2 divisions) Great Britain 2,000,000 men (approximately 45 divisions completed) 5,000 frontline planes Number of divisions to be added, 7-8; number of planes to be added, 2,000-2,500 during year. Strength can be increased gradually. Near East 150,000 men (10 divisions) 300 planes Northern Africa 300,000 men (16 divisions) 700 planes Western Africa Some U.S. Troops indicated. Southern Africa 80,000 men (5 divisions) 200 planes Madagascar British 1 division India 500,000 men (British Army, 7 divisions; India Army, 23 divisions) 350 planes One division can be organized monthly. Ceylon (1-2 divisions) Canada 130,000 men (5 divisions) 250 planes
Estimate of Possible Increases in U.S.-British Plane and Tank Production (May 1942)
Present Future United States Monthly output of approx 2,700 planes and 500 tanks By middle of 1943 the monthly output will be approx 3,200 planes.
By 1943 - 3,000 tanks monthly.
Great Britain Monthly output of 1,300 planes India Aircraft assembly plants only Canada Monthly output of aircraft, approx 500 Australia Monthly output of aircraft, approx 60
even though the enemy might not surrender, sufficient damage could be inflicted to reduce the Chungking Government's position to that of a local government, thus greatly enhancing the chances of a settlement of the China Incident. Furthermore, occupation of this area would prevent the British or United States Air Forces from raiding Japan from bases in China.
Imperial General Headquarters regarded the submission of the Chungking Government as important but changing conditions both in Japan and abroad prevented immediate action being taken. Preparations which would not involve the transfer of troops or matériel from the Southern Area were ordered so that the operation could be undertaken as soon as the overall situation permitted.
The plan required the annihilation of the main force of the Chinese Central Army, the capture of key sectors in Szechwan Province, the destruction of enemy bases of resistance and the capitulation of the Chungking Government. To attain these objectives, the main force of the China Expeditionary Army from the Changan area and an element from the Ichang area were to advance toward the Szechwan Plains. During this period, the already occupied areas were to be maintained and secured with the minimum strength necessary, and political and propaganda measures were to be closely coordinated with the operations against Chungking.
Plans called for the operation to be undertaken in the spring of 1943 but lack of shipping, combined with severe reverses in the
Southern Area, compelled Imperial General Headquarters first to suspend and finally to abandon these plans.
Aleutians, Midway and the Southeast Area Operations Plans
In early 1942 the Navy Section of Imperial General Headquarters began to emphasize the necessity of occupying Australia in order to cut air and sea communications between Australia, New Zealand and the United States, as it was becoming increasingly obvious that the United States planned to use Australia as a base from which to conduct future counteroffensives.
The Army General Staff of Imperial General Headquarters strongly opposed this idea as it considered that, with the available fighting strength, the occupation of Australia was clearly beyond their offensive capacity. Furthermore, it argued that such an operation
must fail as the necessary military supplies could not be maintained due to shortage of shipping. Lastly, it was not possible to provide the ten or more divisions estimated as necessary to carry out such an operation.
Conferences were held and finally it was decided to give up the idea of invading Australia in favor of a plan to occupy the Fiji Islands, Samoa and New Caledonia. In this way it was hoped to isolate Australia by employing Japanese naval and air forces to be based on these islands to cut the sea routes from America. In addition, the enemy counterattack potential was to be gradually eliminated by hitting enemy bases from the air and sea and by strengthening the eastern New Guinea area by the occupation of Port Moresby.
The Army General Staff favored this plan as it would not require a large force.
Plans were developed to seize Port Moresby before the enemy had an opportunity to build up its strength but during the Coral Sea Battle the Japanese Fleet lost many of its carrier planes. Since carrier planes were essential for an amphibious attack, the Port Moresby invasion by sea had to be postponed.
The next step was to have been the occupation of Fiji, Samoa and New Caledonia. The Navy, however, suddenly demanded that the plan be changed and the Commander in Chief of the Combined Fleet insisted that Midway be occupied. Navy Section, Imperial General Headquarters, at first, was opposed to this operation on the grounds that while the invasion of Midway itself might be accomplished with comparative ease, the task of supplying the island after its capture would be difficult. In addition, if the enemy should launch a counteroffensive after the fall of Midway, it would be extremely difficult for Japanese forces based a great distance from the islands to Repulse such an offensive. The Combined Fleet Commander in Chief, however, finally won approval of his plan. The Navy then asked the Army to cooperate in the operation by committing one infantry regiment. The Army did not approve of this change in plans but, after negotiations, finally acceded to the Navy's demands.
The new plan called first for the occupation of the Aleutians and Midway and then for the occupation of Fiji, Samoa and New Caledonia.
The main body of the naval force to be used for the Midway Operation did not return from the Indian Ocean until the latter part of April. This left little time to complete adequate preparations, but as the Combined Fleet still wished to launch the operation as soon as possible, it was decided that it would be undertaken in June. The main reason for this was that any delay beyond 7 June meant that it would have to be postponed for a full month in order to take advantage of the pre-dawn moonlight for night action by carrier air groups.
The Army forces to be used during the first phase of the operation were:
Aleutians: North Seas Detachment, (composed of one infantry battalion and one engineer company, under the command of Maj. Matsutoshi Hozumi). Midway: Ichiki Detachment, (composed of one infantry regiment, one engineer company and one antitank company under the command of Col. Kiyonao Ichiki).
Both Army units were to operate under the Navy. The Navy was to commit the main body of the Combined Fleet.
The operational policy stated that there were to be two operational areas - Aleutians and Midway - but that the operations in
these two areas were to be closely coordinated. While the occupation of the strategic islands was an important objective, the interception and destruction of the enemy fleet, which was expected to counterattack, was no less vital.
On 5 May 1942, Imperial General Headquarters issued Army Order No. 626 stating:
Imperial General Headquarters plans to occupy Midway Island.
The Ichiki Detachment commander is assigned the mission of occupying Midway Island and will cooperate with the Navy forces for that purpose.
After assembling at the point of rendezvous, the Ichiki Detachment will be placed under the operational command of the 2d Fleet commander.
Detailed directives will be issued by the Chief of the General Staff.
On the same day, Imperial General Headquarters issued Army Order No. 628, which read:
Imperial General Headquarters plans to occupy the western Aleutian Islands.
The North Seas Detachment commander will cooperate with the Navy forces in carrying out the occupation of Adak, Kiska and Attu Islands.
After assembling at the point of rendezvous, the North Seas Detachment commander will be placed under the operational command of the 5th Fleet commander.
Detailed directives will be issued by the Chief of the General Staff.
Progress of the Midway and Aleutian Operations
Without having had time to study the enemy situation fully, during the first days of June the operational strength of the Combined Fleet committed to these operations moved toward Midway and the Aleutians.17
As the forces participating in the Midway Operation approached the island, the enemy situation remained unknown. Suddenly, the battle was joined. Japanese losses were enormous and, in consequence, on 5 June the Commander in Chief of the Combined Fleet ordered the invasion force to withdraw.18
In view of the defeat at Midway, Imperial General Headquarters modified its plan for an attack against the Aleutians. It ordered Attu and Kiska captured but cancelled as too risky the landing on
Adak. Earlier, the forces assigned to invade Attu and Kiska had turned back but they now resumed their courses. On 7 and 8 June
respectively, the landings on Attu and Kiska were carried out smoothly without any enemy interference.
As a result of the Battle of Midway, the Combined Fleet had not only lost the majority of its aircraft carriers but, in addition, most of the veteran carrier pilots had been lost. The carrier force had contributed heavily toward the Navy's success in the early days of the war and, in an endeavor to regain some of its fighting strength it was decided that for a time any major engagement should be avoided As an immediate step, the operation planned to occupy New Caledonia, Fiji and Samoa Islands as staging areas for an attack against Port Moresby, was first postponed for two months and later completely abandoned.19
Defensive Adjustments of the Southern Army in June 1942
For the most part at this time, the Southern Army concentrated on restoring its strength and training its troops. It set up military administration in the occupied areas and regarded the situation generally as satisfactory.
Imperial General Headquarters gradually withdrew units from the Southern Army and returned them to their parent organizations.
An outline of Imperial General Headquarters' order to the Southern Army of 29 June stated:
In order to pursue the Greater East Asia War, Imperial General Headquarters will maintain important areas in the Southern Area. These areas will be strongly defended and self-supporting.
The Commander in Chief of the Southern Army will be charged with securing and maintaining the important southern areas. At the same time, in cooperation with the Navy, the Southern Army will prepare for future operations against outlying important areas.
Burma, British Malaya, Sumatra, Java and British Borneo will be secured and military administration established.
The Southern Army will cooperate in the defense of Thailand and Indo-China.
Pressure will be continued against Chungking from the direction of Burma, Indo-China and Thailand.
When necessary, air attacks will be carried out against enemy forces in India and China.
Definite orders in regard to ground operations against the interior of China will be published at a later date.
When necessary the Southern Army will assist the Navy in defending areas for which the Navy is primarily responsible.
Necessary propaganda and fifth column activities will be carried out in India, Australia and China.
Army-Navy Central Agreement Specifying Responsibilities in the Southern Area
In order to defend the strategic regions in the Southern Area, on 29 June Imperial General Headquarters published an Army-Navy Agreement specifically setting forth the responsibility of each service. It directed the Army and Navy to cooperate in preventing the enemy from launching a counteroffensive by land, sea or air. Remnants of enemy forces in the occupied areas were to be promptly mopped up and, if necessary, neighboring strategic areas were to be occupied. The Army and Navy were to cooperate closely in strengthening occupied areas and any attempted enemy counterattack was to be quickly crushed. Sea lanes in the Southern Area and between Japan and the Southern Area were to be kept clear and safe.
It further stated that:
The Navy, while neutralizing, searching and patrolling the waters around the occupied areas, will carry out air and submarine operations in the Australian waters and the Indian Ocean at the proper time and, should the situation demand, employ surface elements to attack enemy surface craft on the high seas.
The Army will employ its air force to attack enemy air forces in southwestern China, northeastern India and other strategic points under its control and, if required, will cooperate with the Navy in attacking enemy surface craft in neighboring waters.
Basically the Navy was required to defend the seas around the occupied areas, in addition to being responsible chiefly for the defense of the Andaman Islands, Nicobar Islands, Christmas Island,
the Lesser Sunda Islands, and the Netherlands East Indies (excluding Java and Sumatra) and Dutch Borneo. The Army was responsible for the defense of the remainder of the Southern Area. If the situation required it, however, the Army and Navy were to cooperate with one another and to be held Jointly responsible for the defense of a particular area.
The Navy was responsible for the sea defense of the main harbors (Singapore, Manila, Soerabaja, Batavia, Davao, Rangoon and Penang) in the important Southern Area. It was ordered to prevent the infiltration of enemy submarines by blockades and to strengthen harbor defenses. To do this it was authorized to establish ground defense installations manned by necessary Navy personnel at points in the Army's zone of responsibility, after first conferring with the local commander. Details concerning the escort of Army ships were to be decided by the local Army and Navy commanders.
The Navy was to cooperate with the Army in defending Timor until mid-August at which time the Army was to assume full responsibility for the defense of the island (except air defense, which was to remain a joint action). In mid-August an infantry battalion was to be assigned to defend the island until the end of the year when, unless the situation changed radically, this force was to be withdrawn.
Establishment of Air Bases in Important Southern Zones
With the temporary conclusion of operations in the Southern Area, Imperial General Headquarters ordered the Air Force to strengthen its bases in such important areas in the south as Singapore, French Indo-China, Thailand, Burma, Malaya, Sumatra, Java and the Philippines. As it was planned to repair and supply planes at these bases it was necessary to increase their capacity. The Air Force was also ordered to establish the following air lines in order to provide liaison between the military air bases and routes of communication within the Southern Area:
- Formosa - Philippines - Eastern Borneo - Java
- Formosa - Philippines - Western Borneo - Singapore
- Hong Kong - Southern French Indo-China - Eastern Malaya - Sumatra - Java
- Hong Kong - Northern French Indo-China - Thailand - Western Malaya - Sumatra
- Philippines - Southern French Indo-China - Thailand - Burma
On 10 July, Imperial General Headquarters issued an order stating that the organization of all air units under the direct control of the Southern Army was dissolved and published the order of battle of the new 3d Air Army.20 The 3d Air Army was then assigned to the
order of battle of the Southern Army. At this time the 3d Air Division was transferred to the China Expeditionary Army, leaving only the 5th Air Division as the main strength of the 3d Air Army.
During the latter part of June the Army General Staff instructed the Commander in Chief of the Southern Army to make every endeavor to support his army locally and to cut down as much as possible on his supply demands from Japan. Saigon and Singapore were named the main supply bases for the Southern Army.
The Southern Army commander was given complete control of the railway systems within the occupied areas and was instructed to place them in working order. It was hoped that, except in remote areas, this would enable him to supply adequate military, resources (raw materials) and essential public transportation.
Critical shipping shortages made it necessary for Imperial General Headquarters to exercise extremely close control on ships operating to and from the Southern Area carrying operational cargo. Although the ships were operated by the Shipping Transportation Command, they were dispatched as being under the direct control of Imperial General Headquarters. This was done to prevent area commanders from taking control of the ships while they were operating within their commands.
This shortage of transportation proved to be a major problem in the consolidation of the occupied areas.
The Southern Army commander was charged with the responsibility for inter-area transportation in the south, to include transportation to the Navy Administration Area and the Philippines, except when otherwise stated. In addition, he was responsible for intra-area transportation, except the Philippines. For this purpose, he was authorized to use the local agencies of the Shipping Transportation Command stationed in the Southern Area.
The Southern Army commander had complete jurisdiction over non-military communications in the occupied areas. He, in turn, made subordinate commanders responsible for the handling of communications within his area and, at the same time, took steps to reorganize the non-military communications in order to relieve the Army Signal Unit's responsibilities.
On 18 April 1942, United States planes carried out their first surprise attacks on Japan from an aircraft carrier and, having dropped their bombs, flew toward the China mainland. Imperial General Headquarters, fearing further raids on the Homeland from air bases and carriers in the Pacific, as well as from bases in China, with the raiding units terminating their flights in China, ordered the China Expeditionary Army to concentrate on the destruction of enemy air bases in the Chekiang area.
The Commander in Chief of the China Expeditionary Army desired
to carry out operations against the enemy airfields in Chekiang Province after the 13th Army had conducted its operation in the Kuangte area. Toward the end of April, however, Imperial General Headquarters issued an order stating that the operation against the airfields was to be undertaken at the earliest possible moment. It ordered the China Expeditionary Army to use the main force of the 13th Army, reinforced by elements of the 11th Army and North China Area Army, to undertake this operation. Ground units were to capture the air bases in the vicinity of Lishui, Chuhsien and Yushan, while other airstrips were to be neutralized by the Japanese Air Force. The air bases were to be occupied for a specified time, after which, together with the accompanying military installations and lines of communication, they were to be completely destroyed. The time for the withdrawal was to be announced later.
As it was necessary to undertake this operation with the utmost speed, it was not possible to work out detailed plans ahead of time. On 15 May, the 13th Army launched its initial attack and advanced much faster than had at first been hoped.
The Navy closely cooperated with the 13th Army by sweeping mines from the Fuchun Chiang and by carrying out diversionary actions along the entire coast of central and southern China.
Late on 31 May, the 11th Army began fording the Fu Ho. It quickly defeated the enemy on both banks of the river, and continued to advance. By night on 3 June, it had advanced to a line
linking Chinhsien, Yunshanshih and the western Linchuan Mountains, while the enemy, without putting up effective resistance, retreated to the south and southeast.
By the beginning of July, the Chekiang-Kiangsi Operation had been successfully completed. Imperial General Headquarters, however, desired the area along the railway line occupied temporarily in order to transport captured materials, particularly railway material, to the rear. At first it was estimated that this would require about one month but bad weather and other factors extended the period of occupation to two months.21
Part 2 (July - December 1942)
With the initial conquest of the Southern Area successfully completed, at the end of June Imperial General Headquarters ordered the forces in that area to "hold and stabilize the strategic regions in the Southern Area."
Although the situation to the southwest had remained quiet during the first half of 1942, enemy counterattacks from the southeast were mounting in intensity until, on 7 August, a strong enemy force assaulted and occupied Guadalcanal and Tulagi in the Solomons.
Plans were drawn up for an invasion of Ceylon in the event the German-Italian forces should advance to the west of the Indian Ocean but Imperial General Headquarters did not believe that there was any great likelihood of this operation eventuating.
In the early days of the Pacific War the progress of the Japanese forces had been phenomenal - victory had followed victory. These conquests, however, had not been without cost to Japan in men, equipment and particularly in ships, while at the same time the enemy lines of communications between the United States and Australia were being greatly strengthened. Imperial General Headquarters, therefore, had planned to capture the Fiji Islands, Samoa and New Caledonia in order to strengthen its strategic position in the southeast Pacific and to cut the lines of communications between Australia
and America. Losses sustained during the Coral Sea Battle, however, made it necessary to suspend these plans, and later, after the enormous losses at Midway, the commander of the 17th Army was notified that the invasion of these islands was further postponed and that a drive overland to Port Moresby was being planned. Finally, on 11 July, the 17th Army commander received orders releasing him entirely from the mission of invading Fiji, Samoa and New Caledonia and instructing him to cooperate with the Navy in attacking and securing Port Moresby and in mopping up important positions in eastern New Guinea and adjacent islands at an appropriate time. Of 18 July, the 17th Army ordered the South Seas Detachment to land at Buna. From there it was to march over the Kokoda trail and capture Port Moresby and the airfield nearby. On the 22d, on arriving at Rabaul, the 17th Army commander received favorable reports of the landings and the advance toward Kokoda. As a consequence he recommended to Imperial General Headquarters that the sea-borne attack be suspended and Port Moresby be attacked overland. His recommendation was immediately approved and, on 28 July, the Army-Navy Agreement in regard to an overland attack was published.22
The United States Marine Corps opened its counteroffensive by landing on Guadalcanal and Tulagi on 7 August - just about the time the invasion of Port Moresby by the main force of the South Seas Detachment was getting under way. It was not until informed of this landing that most of the senior officers of the Army General Staff became aware of the fact that the Navy had constructed an airfield on Guadalcanal and deployed a naval guard unit of about 240 men and a construction unit of about 2,700 men on Guadalcanal as well as about 40 naval air force personnel, a naval guard unit of about 200 men and a construction unit of about 200 men at Tulagi and Gavutu.23
At 0530 on 7 August, 8th Fleet Headquarters at Rabaul received a radio report that Guadalcanal and Tulagi were being heavily bombarded by enemy air and naval forces. Tulagi reported that approximately 30 to 40 transports, escorted by one battleship, two aircraft carriers, ten or more cruisers and 15 destroyers, had begun landing troops on Guadalcanal and Tulagi under powerful air and naval support. The enemy quickly overcame the small Navy units and occupied Tulagi and the airfield at Guadalcanal.
Counterattack by the 8th Fleet
Upon receiving the report of the enemy's landing, Vice Admiral Mikawa, commander of the 8th Fleet, left Rabaul at 1430 on 7 August with five heavy cruisers, two light cruisers and one destroyer and rushed down the Slot (narrow waters between the two chains of the Solomons) toward Guadalcanal. The Fleet infiltrated through a gap in the enemy destroyer picket after nightfall and launched a surprise attack at 2330 hours between Savo and Cape Esperance against the main surface elements.24 After about 50 minutes of fierce engagement not a single enemy warship remained afloat and the gains were reported to be eight cruisers and six destroyers sunk.25 The Fleet, in anticipation of an enemy air attack after daybreak, then turned back toward Rabaul without attacking the enemy transports that crowded the anchorage.26
17th Army Reinforcements
Upon receipt of the report of the attack on the Solomons, the Army General Staff, on 10 August, ordered the Ichiki Detachment
(being held as a reserve on Guam Island) to advance to Truk, where it was to come under the command of the 17th Army. In addition, the Aoba Detachment, which had been transferred to the 14th Army on 20 July, was returned to the command of the 17th Army. On 23 August, in order to take advantage of the 8th Fleet's victorious surprise attack, the 17th Army commander was ordered to continue operations in Eastern New Guinea but, at the same time, in cooperation with the Navy, to recapture important areas in the Solomons.
The operational strength for these operations was to be:
Army: 17th Army (South Seas Detachment, 41st Infantry Regiment, Ichiki Detachment, 35th Infantry Brigade, Aoba Detachment and others.) The total strength was approximately 13 infantry battalions. Navy: Southeast Area Force (main force of the 8th Fleet and 11th Air Fleet). Main force of the Combined Fleet (mainly the main force of the 2d and 3d Fleets).
Units of the 17th Army were to depart immediately and, in cooperation with the Navy, to attack and destroy the enemy forces on Guadalcanal and capture strategic points, particularly the airfield. Efforts were also to be directed toward the capture of Tulagi as soon as practicable.
Surprise Enemy Landing on Makin Atoll
The enemy in the Guadalcanal area continued to be active and steadily built up its strength. On 17 August, the Americans made a surprise landing from two submarines on Makin Atoll in the Gilberts.
The Combined Fleet commander ordered the 4th Fleet commander to capture Makin immediately and to carry out amphibious raids against Naul and the Ocean Islands in an effort to stabilize the situation in the Central Pacific Area. After destroying the installations on Makin the enemy withdrew. The 4th Fleet then occupied it and strengthened its defenses.
17th Army on Guadalcanal
In compliance with Imperial General Headquarters orders, the Commanding General of the 17th Army ordered the Ichiki Detachment to retake Guadalcanal.
The Advance Unit (one infantry battalion and one engineer company commanded by the Detachment commander) left Truk for Guadalcanal aboard six destroyers. Encouraged by reports that the enemy was withdrawing to Tulagi the Advance Unit, which had landed at Point Taivu late on the night of 18 August, marched westward at once, without waiting for the arrival of the rest of the Detachment. The previous night, the Navy had sent an element of the Yokosuka 5th Special landing Force, that had been based on Truk, to Guadalcanal. This naval force landed at Tassafaronga and succeeded in establishing contact with the Naval landing Force on the island.
On the night of the 20th, the Advance Unit of the Ichiki Detachment launched an attack from the banks of the Tenaru River, which flows past the eastern edge of the airfield, but failed to make any
headway. The following afternoon, a powerful enemy force counterattacked killing most of the Advance Unit, including the commander and practically all the officers. The survivors, numbering little more than 100 men, were forced to withdraw to the vicinity of Point Taivu where they awaited the arrival of the rest of the Detachment.
On 20 August, the enemy began using Guadalcanal airfield.
It had been planned to land the second echelon of the Ichiki Detachment on Guadalcanal on 22 August, with part of the 35th Infantry Brigade (the Kawaguchi Detachment, composed mainly of the 124th Infantry Regiment, and commanded by Maj. Gen. Kiyotake Kawaguchi, commander of the 35th Infantry Brigade) to land on the 28th. However, as all contact with the Advance Unit had been severed on the 22d, it was decided to postpone the second landing until the 24th. On 23 August, the 2d and 3d Fleets advanced to the waters north of the Solomons. Meanwhile the transports were being tracked by enemy aircraft north of Guadalcanal. It was estimated that the enemy was waiting for the transports to draw closer so that it could attack with its land-based air force on Guadalcanal and the carrier task force cruising to the southwest of the Solomon Islands. The Commander in Chief of the Combined Fleet, therefore, ordered the landing of the remainder of the Ichiki Detachment postponed for yet another day (until 25 August). At the same time, he ordered the entire air and surface forces of the Combined Fleet to attack and destroy the carrier task force and to neutralize the enemy air force.
In addition, he ordered the Kawaguchi Detachment, waiting at Truk aboard transports, to prepare to land on Guadalcanal on 28 August, thus taking advantage of the impending battle.
On the afternoon of the 24th, the 3d Fleet sighted the enemy carrier striking task force south of Stewart Island and immediately launched an attack. It succeeded in heavily damaging one carrier and inflicting some damage on another. The 2d Fleet endeavored to cooperate with the 3d Fleet in order to expand the gain but, because of fuel shortage, was compelled to abandon the pursuit. The Ryujo, a light aircraft carrier, which was operating as a detached force of the 2d Fleet, sustained heavy damage and finally sank. Meanwhile, the 2d Destroyer Squadron, which was escorting the Ichiki Detachment, suffered some damage and was ordered to retire to the northwest.
Imperial General Headquarters announced the damage inflicted on the enemy during this engagement as one aircraft carrier seriously damaged and one aircraft carrier and one battleship damaged.27
The results of this battle were not considered great enough to insure the safe passage of the convoy carrying the Ichiki Detachment for the landings on Guadalcanal. The Commander in Chief of the Combined Fleet, therefore, ordered the five destroyers escorting the convoy to bombard the airfield on Guadalcanal on 24 August. They,
however, were unable to prevent enemy air activity and the convoy was subjected to repeated air attacks, making debarkation impossible. The Commander in Chief then decided to send both the Ichiki Detachment and the Kawaguchi Detachment aboard destroyers and attempt to land them at night as they were urgently needed on Guadalcanal. The Army did not approve of the troops being transported aboard destroyers as it placed a great restriction on the transportation of heavy weapons and supplies, but they were compelled to agree.
On 29 August, the Army General Staff issued orders placing the 2d Division, which was stationed in Java under the command of the 16th Army, in the order of battle of the 17th Army. In addition, it added five infantry battalions to the number to be used by the 17th Army in its operations in the Solomons and against Port Moresby, making in all 18 infantry battalions. There were no changes in Navy strength. Priority was given to the recapture of Guadalcanal, particularly airfields, with Tulagi next in importance. This was a shift from the previous plan which called for the concurrent execution of the Solomons and New Guinea Operations. Rabi Airfield in the Milne Bay area was to be secured during this revised operation and, after the recapture of the Solomons, navy and air strength were to be diverted to New Guinea. Ground forces were to advance southward from Kokoda and, in a joint operation with a task force (Army and Navy units cooperating) which was to land at Port Moresby, were to occupy the airfields around Port Moresby.
While the main body of the Kawaguchi Detachment was preparing to launch its attack to retake the airfield at Guadalcanal (in spite of the heavy losses it had already sustained and the enormous difficulties encountered in advancing through the jungle) the Combined Fleet decided to support the Detachment by employing its air and submarine forces in the Southeast Area to prevent reinforcements or supplies reaching the enemy on Guadalcanal; drawing out enemy task forces with a decoy transport (two ships) to destroy them with the 2d and 3d Fleets; and using destroyer squadrons of the 8th Fleet to assault the anchorage of Guadalcanal on the night of the 12th, in addition to attacking enemy ships and bombarding the land area.
On the night of 12 September the Kawaguchi Detachment finally reached the right bank of the Lunga River and launched its attack, but failed to penetrate the enemy positions. The Combined Fleet continued to support the Detachment according to plan, but had no idea of the true situation as communications with the Detachment were completely severed. On the 15th, having suffered very heavy losses, the Detachment commander decided to attempt to concentrate his force in the area west of the Matanikau River and there await reinforcements.
The total Japanese strength participating in the Guadalcanal Operation since the landing of the Ichiki Detachment on 13 August was in the vicinity of 6,200 men. Losses to the end of September were estimated to be about 1,200 men.
In the meantime, the South Seas Detachment continued its swift drive in eastern New Guinea and, by about 5 September, had reached the crest of the Owen Stanley Range.
On 18 September, the Army General Staff made further changes in the operational outline for conducting operations in the Southeast Area. It stated that following the increase in Army strength and matériel, combined Army and Navy forces were to capture Guadalcanal Airfield. While awaiting these reinforcements, the Navy was to prevent enemy personnel and supplies from being brought into the Solomons. Before the beginning of the Port Moresby Operation, Rabi Airfield was to be taken by a joint action of the Army and Navy. The Navy was to strengthen and complete airfields in the Solomons and eastern New Guinea. After capture of important areas in the Solomons and eastern New Guinea, the following outlying points were to be secured:
Solomon Islands (to include San Cristobal and Rennel Island)
Rabi, vicinity of Samarai
Port Moresby and vicinity (including KID Airfield)
The coastal area of Papua Gulf was to be secured, if the situation permitted.
With its preparations for another attack on Guadalcanal completed, the 17th Army had ordered the 2d Division to launch an attack but weather and an overwhelmingly superior enemy combined to defeat the Division.
In eastern New Guinea the South Seas Detachment, which had overrun the strategic line indicated by the 17th Army, found that it had dangerously extended its supply lines as the deep gorges and razorbacked ridges of the Owen Stanley Range made it impossible to bring in supplies, even by pack horse. In addition, the enemy was gradually gaining air superiority. Finally, it became necessary to order the Detachment to withdraw to the right bank of the Kumusi River.28
Situation Review and Plans (October 1942)
Toward the end of October, Imperial General Headquarters, after a thorough review of the situation, estimated that the enemy might be considering counterattacks from China, the Indian Ocean, Southwest Pacific, Southeast Pacific or the Northeastern Area. In China, however, the United States Air Force would have considerable trouble in launching a large-scale attack as it was having difficulty in bringing in planes and supplies and the condition of the airfields was poor. In the Aleutian Islands, except from March to May and from September through October, weather conditions would prevent large-scale operations being undertaken. It appeared therefore, that the most likely place from which the enemy would counterattack was the Southeast Pacific. Not only did a chain of islands across the Pacific link America and Australia but the islands surrounding Australia made it possible to deploy large army, navy and air forces
in the area. This would enable them to launch operations to recapture the southern occupied territory and invade the South Sea Islands, as well as to carry out air raids against the important resources areas. Desiring to strengthen the Southeast Pacific Area, on 16 November, Imperial General Headquarters activated the Eighth Area Army and placed the 17th Army (2d, 38th and 51st Divisions) and the newly activated 18th Army (South Seas Detachment and 41st Infantry Regiment) under its command. The 17th Army was to concentrate on overcoming the enemy in the Solomons and the 18th Army was ordered to assume responsibility for the operations in New Guinea. The 35th Infantry Brigade and other units under the control of the 17th Army were reinforced in order that they might renew the attack against Guadalcanal. About the same time, the 12th Air Brigade and air service units from the Southern Army were placed under the direct command of the Eighth Area Army.
Although it was realized that several more divisions would be necessary to carry out the operations in the Southeast Area, (including New Guinea) the choice of the divisions and the areas from which they were to be drawn was to be decided only after a careful over-all study of the operational situation for the coming year had been made.
Southeast Area Operations (November - December 1942)
In the Solomons and New Guinea the situation was daily becoming
more critical. In an effort to strengthen the 17th Army, whose offensive on 24 October had failed, the Army General Staff attempted to send a convoy of eleven fast transports with reinforcements and supplies to this area. On 14 November the convoy was attacked by a strong enemy air force in the waters northwest of Russell Island. Seven of the eleven transports were forced to fall out of line but the convoy continued its advance. Finally, the transports, supported by the 2d Fleet, reached Guadalcanal but, coming under enemy bombardment on the 15th, one transport after another burst into flames with the result that only about 2,000 men, 260 boxes of ammunition for mountain and field guns and 1,500 sacks containing approximately 3,000 bushels of rice were unloaded.
The enemy losses reported by the Army General Staff during this operation were eight cruisers and four or five destroyers sank; two battleships, three cruisers and three or four destroyers badly damaged.29 Japanese Navy losses were two battleships, one heavy cruiser and three destroyers sunk.
Attempts to supply Guadalcanal by small craft also failed, making it almost impossible to send any supplies to the hard-pressed troops on that island.
The 17th Army was ordered to maintain its present positions until the Eighth Area Army could prepare a large-scale ground operation, as well as effective air operations to secure important positions in both the Solomons and New Guinea. It was vital that major points near the present positions on Guadalcanal as well as strategic positions on New Guinea be secured. Air bases were to be constructed on the Solomons regardless of cost.
The Eighth Area Army commander was ordered to cooperate with the Navy in the occupation of the Solomons and, at the same time, to secure the above-mentioned positions on New Guinea. Meanwhile, the Navy had planned to use the main strength of the Combined Fleet during the coming operation.
The Army and Navy were ordered to cooperate in increasing and completing the necessary air bases for the Solomons and in strengthening the defense, especially air defense, of all strategic points. They were to secure key positions on Guadalcanal and to make every effort to recover their fighting strength in an endeavor to expedite operational preparations.
The Navy was ordered to prevent enemy reinforcements reaching the Solomons, while the two services were to cooperate in destroying enemy air power. In addition, Tulagi and other strategic areas in the Solomons were to be captured as soon as possible.
Orders for the New Guinea area read that during the Solomons Operation, the Army and Navy were to cooperate in securing strong
strategic bases in the vicinity of Lae, Salamaua and Buna. Air activities were to be intensified; airfields were to be increased and maintained, while preparations for subsequent operations were to be completed. Madang and Wewak were to be occupied as quickly as possible and other strategic areas to be mopped up and secured.
When publishing the operational schedule for recapturing Guadalcanal, Imperial General Headquarters stated that air bases would be completed by the end of December; the Army and Navy would start air operations at the beginning of January 1943; a large number of troops and a large quantity of munitions were to be transported to Guadalcanal between the beginning and middle of January and the ground attack was to be launched toward the end of January.
On 27 November 1942, the Army General Staff further reinforced the Eighth Area Army with the 6th Air Division, newly organized in Japan.
Many difficulties were encountered in completing the necessary preparations. Enemy air superiority made transportation of munitions and reinforcements by destroyers and smaller craft very difficult while supplies in the Southern Area were steadily shrinking. Constant air and sea attacks, made it impossible for the Navy to transport the quantity of munitions necessary to launch the planned attack to recapture important positions in the Solomons. Lack of materials prevented the Army from establishing the required airfields.
Imperial General Headquarters estimated that it would be necessary to requisition a further 300,000 tons of shipping to undertake the planned operation against the Solomons but without seriously affecting the overall national economy this was not possible.30 The shipping plan formulated prior to the outbreak of war had been based on minimum requirements and had not foreseen the tremendous shipping losses the Navy had sustained. After serious thought, on 31 December 1942 Imperial General Headquarters was forced to give up the plan to recapture the southern Solomons.
Prior to this, on 21 December, the Army General Staff had changed the order of battle of the Eighth Area Army. It assigned the 41st Division and the 21st Independent Mixed Brigade directly to the Eighth Area Army; the 6th and 20th Divisions to the 17th Army and the 51st Division to the 18th Army.
Changes in Other Areas
On 10 November 1942, in order to more closely coordinate the Southern Army forces in French Indo-China and to create an agency responsible for both the political and strategic negotiations with the Government of French Indo-China, Southern Army organized the French Indo-China Garrison Army with headquarters at Saigon.31
On 18 November, in an effort to bolster the rapidly deteriorating situation in the Solomons, Imperial General Headquarters ordered Southern Army to dispatch elements of the 5th Division to Rabaul to be placed under the command of the Eighth Area Army.
As air attacks against India had been suspended, it was essential that the defense of the Southwest Area be tightened by increasing the strength in that area and building fortifications at major points along the Indo-Burma border and on Andaman, Nicobar, Sumatra and Java. The Burma Area Army Headquarters was established to strengthen the command system and the Army Air Force ordered to patrol the Indian Ocean area.
Guerrillas continued to harass the Japanese troops in the Philippines making it necessary to station an Independent Garrison Unit in Manila to help restore order in that city.
Miscellaneous Actions During the Second Stage
On 28 July 1942, Imperial General Headquarters ordered the Commander in Chief of the China Expeditionary Army to maintain key points in the Chinhua sector after the termination of the campaign in Chekiang Province. The order read that a force would remain to maintain those important regions in the vicinity of Chinhua from which such raw materials as fluorite, copper and tin were obtained. Consideration, however, was to be given to the conservation of manpower.
In China the large enemy bases for supplies and reorganization of forces, as well as approximately one-half their war production enterprises, were located in Szechwan Province. This area was known also to be used as a pool for American air force strength. As the operations in the south had progressed favorably, in the spring of 1942 Imperial General Headquarters estimated that, if the Japanese forces could deal a strong blow to the Chinese Central Army which guarded this area and, at the same time, destroy the Chungking Government's bases of resistance, the chances of promoting a settlement of the China Incident would be greatly improved. Such preparations were ordered, therefore, as would not affect other areas to any great extent, since it was considered necessary to use every opportunity to conduct operations against China when the over-all situation permitted.
The strength to be employed was to be the China Expeditionary Array to which elements from Japan, Manchuria and the Southern Area were to be attached.
During the latter part of September, however, due to the reverses in the Solomons, Imperial General Headquarters decided to postpone temporarily the dispatch of men and matériel required for the Szechwan Operation. later, on 10 December, with the further deterioration of the situation in the south, Imperial General Headquarters ordered the suspension of this operation.32
On 23 September 1942, the Northern Army Command was ordered to dispatch part of its force to the Kuril Islands to strengthen the garrison there, and, on 20 October, it received orders to strengthen the vicinity of Attu with part of the Kuril Fortress Infantry Unit. This unit was then placed under the command of the 5th Fleet commander. On 24 October, the North Sea Detachment was inactivated and the order of battle of the North Sea Garrison (composed mainly of one infantry fortress unit and three infantry battalions) was published. The North Sea Garrison was placed under the command of the 5th Fleet commander and ordered to occupy strategic points in the Aleutians.
Line of Communications (Logistical Support) During First Phase
During the first stage of this phase, while the Japanese Army surged forward victoriously, there was little or no need to worry about interrupted lines of communications. About the beginning of the second stage, however, many difficulties were encountered. In addition to the fact that shipping daily became more critical as the enemy's air superiority increased, it became necessary to make intensive studies of such things as special field rations; a way to control malaria in the tropics, and means of self-support for the armies on distant islands. With the urgent need for ships to find a way to evade enemy air and sea attacks, Palau became an important intermediate supply base but, after a time, even this island did not offer too much protection, and shipping losses continued to mount.
During November and December 1942, the ever-increasing requisitions for ships for the Southern Area began to severely affect the national economy, as well as to place a very definite check on the lines of communications to the China Expeditionary Army.
Manchuria had been used as a base not only to stockpile matériel for the armies in China and the Southern Area but also as a collection base for food and machinery necessary for the economy of the Homeland, In order to facilitate the continued stockpiling of goods in this area, in October 1942 an Inspectorate Office of Supply for the Kwantung Army was established. In addition, Munition Transport Control Detachments were established at important harbors in southern Korea, northern Kyushu, Seto Naikai (Inland Sea) and Hokkaido to strengthen the main transport lines between Japan and Manchuria.
Second Phase of the War
(January - August 1943)
Estimate of Enemy Offensive Potential
At the end of 1942 the Army General Staff regarded several areas as likely places from which an enemy offensive could be launched.
In the Southeast Area it was anticipated that an attack would be made on Rabaul, as this was the main operational base for the Japanese Army, Navy and Air Force. It was thought probable that the enemy planned first to destroy the Japanese forces on Guadalcanal and then to advance northward through the Solomons. In eastern New Guinea they would secure first the vicinity of Buna and then attack Lae and Salamaua from the sea. After penetrating Dampier Strait, the forces from New Guinea would attack Rabaul in a joint operation with the forces from the Solomons. Then, using the north coast of New Guinea as a route of advance, the enemy would next attack the Philippines.
In the North of Australia Area, centering around the Dutch East Indies, the Allies were expected to make synchronized attacks on Aroe and Tanimbar Islands. At the same time, they would probably initiate an advance along the western coast of New Guinea in order to control that area.
In India, the enemy was expected to attempt to recapture Akyab and to intensify air operations. It was anticipated that toward the end of the rainy season they would launch coordinated attacks from the east and west, in an effort to control Burma with the main force of the British-Indian Army operating toward Imphal and the Chungking Army operating toward the Shan sector. In addition, enemy forces would attack strategic points on Andaman Island and attempt to gain control of the Bay of Bengal and the Andaman Sea.
Expansion of submarine operations throughout the entire South Sea area was expected, as well as bombings of important natural resource areas aimed at checking attempts to reinforce the Japanese fighting power.
At the end of 1942, due primarily to losses suffered by the Japanese Navy, especially in air strength and auxiliary ships, the enemy dominated the sea and air around and over Guadalcanal and southeastern New Guinea. Furthermore, the enemy navy and air forces in that area had been greatly strengthened. These circumstances combined to make it almost impossible to send reinforcements to the Japanese army and navy units on Guadalcanal and eastern New Guinea. After mid-December 1942 even transportation of minimum quantities of badly needed supplies aboard small craft operating under cover of darkness became difficult. The units on Guadalcanal and eastern New Guinea, struggling against starvation, combat fatigue, heat, illness and superior enemy equipment were in a desperate condition.
The key to Japan's conduct of the war lay mainly in the adjustment of relations between military operations and shipping. More and more ships were needed hut the total number of available ships was decreasing daily. Shipping losses were unexpectedly high and it was impossible to replace them. Moreover there was a sharp decrease in the number of ships available to transport the raw materials vitally necessary for the basic requirements of the nation.
In Europe, Germany was entering its second winter of war against the U.S.S.R. and had turned to defensive tactics, while the fighting power of the Allied Forces was rapidly being built up in the European Theater as well as in the Far East.
Faced with these facts, Imperial General Headquarters reluctantly decided that it must abandon all thought of attempting to recapture Guadalcanal and postpone plans to occupy eastern New Guinea and the vitally important Port Moresby.
Orders and Operational Plans for the Southeast Area
On 4 January 1943, in order to establish a more favorable position in the Southeast Pacific Area, Imperial General Headquarters had ordered the Eighth Area Army to withdraw from Guadalcanal and Buna. The Commander in Chief of the Combined Fleet and the Commander of the Eighth Area Army were ordered to make coordinated attacks and secure and hold strategic positions in the central and northern Solomons to include New Georgia and Santa Isabel Islands, in addition to the Bismarck Archipelago. All Army and Navy units were to
be withdrawn from Guadalcanal between the end of January and the first part of February. The Army was to be responsible for securing and strengthening the northern Solomon Islands (Shortland, Bougainville and Buka Islands) while New Georgia and Santa Isabel Islands were to be under the control of the Navy.
Navy units were to continue aerial warfare in the vicinity of Guadalcanal and, in cooperation with submarine operations, were to attempt to cut the enemy supply lines.
Operational bases at Lae, Salamaua, Madang and Wewak were to be strengthened and strategic positions north of the Owen Stanley Range in northeastern New Guinea were to be attacked and occupied. Emphasis was to be placed on preparations for operations against such places as Port Moresby. In the Buna area, units were to be withdrawn toward Salamaua at the proper time.
The Army Air Force, assisted by the Navy Air Force, was to endeavor to obtain air superiority in eastern New Guinea by annihilating the enemy air force. In addition, it was to cooperate with ground operations to protect transportation of supplies to vital areas in New Guinea.
The Navy Air Force was ordered to carry out air operations, outside the responsibility of the Army Air Force, in the Solomon Islands and New Guinea. The Army and Navy Air Forces were to support the withdrawal from Guadalcanal by cooperating in destroying the enemy air force in that area.
Working with the Southeast Area Fleet, the Eighth Area Army made the necessary preparations to comply with these orders.
Although under the operational plan published on 31 December 1942 the front line on Guadalcanal was withdrawn, there was no change in the plan to secure a string of operational bases connecting important positions between the Solomons (with Rabaul as a center) and northeast New Guinea (with Lae, Salamaua and Madang as the strategic positions). This new plan forced the Japanese forces to give up the offensive and assume defensive positions. This was a major turning point in the war in this area.
During the second phase of the operations, enemy counterattacks against the outer boundary of the operational areas of the Southeast Area, Burma and the Aleutians daily increased in intensity, while the strength of the Japanese Navy and Air Force grew weaker and weaker. By early February 1943, the units on Guadalcanal had been withdrawn and, in New Guinea, units in the Buna area had pulled back to Salamaua where they prepared to counterattack. Rabaul and strategic points in northeast New Guinea were to be used as operational bases.
In June, the enemy landed near Rendova. They attacked the Japanese air base at Munda and, although the Japanese force resisted stubbornly, it was finally compelled to retire to Bougainville.
In the North of Australia Area, there appeared to be no plans for an enemy offensive prior to the end of August. They did, however, constantly harass the Japanese defensive preparations by air
and submarine warfare, making transportation to the islands extremely difficult.
Although relations between the Japanese Army and the Thai Government remained harmonious during 1942, on 4 January 1943, with the steadily increasing logistic demands being made on Thailand, Imperial General Headquarters felt it wise to organize the Thailand Garrison Army Headquarters to cope with the situation. On 7 January, the organization of this headquarters, under the command of the Southern Army, was completed. 33
In the Burma area in January 1943, Anglo-Indian troops attempted to recapture Akyab but the Japanese Army counterattacked and drove the enemy back along the India-Burma border. Some units of the Chinese Army did cross the Salween River and penetrate the Japanese occupied area but were quickly driven back.
In the Northeastern Area, United States troops landed on Attu Island on 12 May. The Japanese Army and Navy units stationed there resisted stubbornly but, by 29 May, had been annihilated. All Japanese units on Kiska withdrew safely to Paramushir Island on 1 August.
About mid-February, anticipating the Chungking Army's plan to drive into south China, the China Expeditionary Army attacked strategic points on Luichow Peninsula and entered the French Concession
at Kuangchou Bay. It was estimated that the Chungking Army would soon start a drive into south China and that enemy air activity in China would be stepped up.
General Operational Progress
In accordance with the Imperial General Headquarters plan to evacuate Guadalcanal, the Eighth Area Army and the Navy units were forced to withdraw by sea - an unprecedented event in the annals of the Japanese Army. The preparatory operation for the withdrawal was started on 14 January 1943 when the Yano Battalion was dispatched to Guadalcanal by destroyer. At that time the situation on Guadalcanal was so critical that without reinforcements it would have been impossible to hold the line until the evacuation was completed. On 1, 4 and 7 February, assisted by the Navy, the troops were withdrawn -on the first two days to Shortland and on the final day to Bougainville. In all, approximately 9,800 Army and 830 Navy men were evacuated.
Earlier, in an attempt to relieve the troops fighting in New Guinea, the Eighth Area Army planned to land the Okabe Detachment (51st Division, 18th Army) at Lae with orders to secure the Lae-Salamaua area and to advance and capture Wau. On 5 January the Detachment left Rabaul aboard five transports escorted by five destroyers. The convoy arrived at Lae on the 7th, after having been subjected to air attacks for most of the trip. One transport was
sunk but more than half its complement of troops were rescued. During landing operations enemy air attacks were so severe that finally the transports were forced to leave Lae before they had completed the unloading of munitions and supplies. The lack of these supplies was later to become a major problem.
Having assumed command of the units in the area and, in cooperation with the Navy, stationed logistical units in the vicinity of Lae and Salamaua the commander of the Okabe Detachment prepared to advance and capture Wau. Strategically placed Wau, with its small airfield, while occupied by the enemy, posed a constant menace to the Lae-Salam
aua sector. Having assembled at Salamaua, between 14 and 16 January the main force of the Detachment began its advance. Marshes, dense jungle, razor-backed mountains, kunai grass, as well as the impossibility of transporting the heavier weapons and signal equipment through the jungle, shortage of weapons and munitions, the lack of food and a high incidence of malaria, all combined to destroy the fighting power of the Detachment. In the meantime, the allies had flown in troops and supplies to reinforce their garrison at Wau. Realizing the impossibility of the task, the 18th Army ordered the Detachment commander to withdraw his troops and secure the key points in the Mubo area.34 The loss of men due to illness during operations in the jungle had not been foreseen. It was realized that if this
operation were to continue the entire Okabe Detachment would be incapacitated. When the Detachment left Salamaua it had marched out with approximately 3,000 men hut on its return to Mubo its troop strength was down to about 1,700, about 70% of whom were suffering from malaria, malnutrition and other diseases.
It was recognized that air superiority was essential in future operations and that the key to success lay in the rapid concentration and development of the necessary military strength and materials and the quick construction and completion of essential airfields and harbor installations. More specific information in regard to terrain was also important.
In preparation for future offensives, the 51st Division (then in Rabaul) was ordered to concentrate at Lae and to secure this important base.
The 18th Army acknowledged the importance of transferring its headquarters to New Guinea in order to accelerate operational preparations but this posed a problem as it was necessary for the Army to negotiate with the headquarters of the Eighth Area Army, the Air Force and the Navy (all in Rabaul) for the transportation of even the smallest units or supplies to New Guinea. Finally, the 18th Array decided to move its headquarters to New Guinea at the same time as it moved the 51st Division, leaving behind a small liaison group.
The Army and Navy agreed that the security of the Lae-Salamaua
sector was vital in determining the outcome of the New Guinea Campaign. It was decided, therefore, that an early shift of major forces to New Guinea be made.
The convoy, carrying the 18th Army headquarters and the main strength of the 51st Division, left Rabaul on the night of 28 February 1943. On 2 March, it was attacked by several B-17's. One of the transports caught fire and sank west of Cape Hollman. Two destroyers, after rescuing some 800 survivors, hurried forward to Lae where they landed the men at midnight on the 2d. The following day, the remainder of the convoy was attacked by approximately 100 enemy planes and, although the Navy Air Force and the warships resisted strongly, four of the eight destroyers and all of the transports were sunk. The 18th Army commander was rescued but although he attempted to persuade the destroyer commander to proceed to either Finchhafen or Sio, the commander refused and, on 4 March, the Army headquarters, together with some 2,000 troops, was returned to Rabaul.35
During this movement, the Army headquarters reported 3,664 men lost and 3,248 rescued; the rescued included those troops carried to Lae by destroyer. Those lost by the 51st Division included most of its more experienced officers.
This was the last large-scale surface operation attempted to Lae. After March, Hansa and Wewak became the landing points for all convoys. Troops then advanced to the front line overland or in small craft along the coast, although enemy air superiority, torpedo boats and an almost entire lack of roads made their advance by these methods extremely hazardous.
Units in the Buna area withdrew by sea and land to Salamaua at the same time as units were being withdrawn from Guadalcanal.
During mid-March, the 2d Division, which had suffered very heavy casualties during the Guadalcanal Operation, was ordered to withdraw to the Philippines where it was to reorganize and attempt to recoup its strength.
In early April, elements of the Army Air Force from other areas were dispatched to the Southeast Area in an effort to bolster the combat capacity of the 6th Air Division,
In June, in an effort to destroy the enemy airfields around Bena Bena and Hagen to the south of Madang, the Eighth Area Army ordered the 6th Air Division to continue its present support missions but directed special emphasis be given to the destruction of air bases at Bena Bena and Hagen. The 20th Division was ordered to capture Bena Bena from the direction of Madang, and an element of the 41st Division was to attack Hagen from the direction of Wewak, Imperial General Headquarters increased army air strength in the Southeast Area by placing the 7th Air Division, which had
been newly activated in the Southwest Area, under the command of the Eighth Area Army commander and advancing the 1st Airborne Brigade to Palau. On 28 July, the 4th Air Army was organized and the 6th and 7th Air Divisions placed under its command. The 4th Air Army was assigned to the command of the Eighth Area Army.
In the Solomons area, the command responsibilities of the Army and Navy were decided by the Army-Navy Central Agreement of 25 March by which the Army was responsible for defending the northern Solomons and the Navy the central Solomons. At first there was some disagreement in regard to the strategic concept as the Navy contended that the main line of defense should be in the central Solomons in order to defend and hold strategic Rabaul by keeping it beyond the effective range of the Allied Air Forces, while the Army argued that, with Guadalcanal as an example, it was impossible to maintain powerful groups so far from the center of supply. After several conferences it was decided that the central Solomons would be used as a forward position and the northern Solomons as the main line of defense. In spite of this, the Navy continued to place great importance on the defense of the central Solomons and the Army finally agreed to increase the strength in that area gradually.
On 30 June, the enemy made surprise landings on Rendova Island and, as soon as the landings were completed, immediately began to bombard Munda. They next landed on New Georgia. Finally, in spite
of fierce resistance by both the Army and Navy units, superior enemy air and ground forces compelled the Japanese forces to withdraw and, on 4 August, the airfield at Munda fell. The enemy continued to press forward and, by the end of September, Japanese troops in the Solomons had withdrawn to Bougainville Island.
In view of the necessity to strengthen the Lae-Salamaua and Finchhafen sectors, the 18th Army commander recommended to the Eighth Area Army and to Imperial General Headquarters that the operation to recapture operational bases at Bena Bena and Hagen be postponed and that emphasise be placed on securing these vital areas. Reluctantly, higher headquarters approved these recommendations.
In late August, although the 51st Division continued desperately to defend the Lae-Salamaua sector, in the face of enemy air, ground and sea superiority it was obvious that they could not hold indefinitely. The Eighth Area Army, therefore, in accordance with an Imperial General Headquarters' order, ordered the 18th Army to "withdraw the forces at Lae and Salamaua if the situation becomes impossible." The situation indeed grew worse until it became impossible to withdraw the troops toward Finchhafen. The 18th Army commander, therefore, ordered the 51st Division commander to assume command of all forces in the area and withdraw them quickly toward Madang through Kaiapit.
Important positions in northeast New Guinea and near Rabaul were located ideally to serve as interrelated operational bases
which would allow full use to be made of navy and air fighting power in the defense line. The Army and Navy did their best to hold these positions but strategic points along the front lines gradually fell into enemy hands until, as the result of an enormous buildup in reinforcements on enemy air bases at Lae and Salamaua, it appeared that Rabaul must be completely isolated.
Situation in the Central Pacific Area
Originally the Central Pacific Islands were garrisoned by small Navy units but, with the situation rapidly growing worse in the Southeast Area, the Army and Navy agreed that it was necessary to dispatch Army forces to reinforce these islands. In mid-April, therefore, the 1st and 2d South Seas Garrison Units (both with a strength of approximately one infantry battalion) were dispatched to the Gilbert and Marcus Islands respectively. The 1st South Seas Garrison Unit, however, was attacked by submarines en route and all transports were sunk. The 4th South Seas Garrison Unit (three infantry battalions and one artillery battalion) was then activated to be dispatched to the Gilbert Islands. In mid-June, Imperial General Headquarters ordered Wake Island to be reinforced by the 3d South Seas Garrison Unit.
In the central Solomons the situation was critical and Imperial General Headquarters considered it essential to strengthen the defenses of the northern Solomons. The 4th South Seas Garrison Unit,
therefore, was transferred to Bougainville Island. On 17 July, Imperial General Headquarters dispatched the 122d Infantry Regiment, 65th Brigade from the Philippines to the Gilberts in place of the 4th South Seas Garrison Unit. While en route, however, this unit was ordered to change its course and to proceed to the Marshall Islands.
In the Central Pacific Area, the 2d South Seas Garrison Unit came under the command of the Yokosuka Naval District commandant while all other units in the area were placed under the command of the 4th Fleet commander.
Orders and Operational Plans for the Southwest Area
Because of the critical situation in the Southeast Area, it was not until the end of February that Army General Staff was able to devote sufficient time to the situation in the Southwest Area to publish a tactical command plan. This plan emphasized the importance of military administration and the defense and maintenance of peace in the occupied areas. It also called for greater effort to be made in the collection of intelligence information. In the face of an attack, the Army, Navy and Air Force were to concentrate their fighting strength wherever it could be used most effectively in the destruction of the enemy. The main effort was to be directed toward Burma and the vital resources area but, should the situation permit, ground operations were to be carried out against northeast India. Public order was to be enforced in the Philippines.
To accomplish the objectives of this operational plan, the areas currently occupied in the Southwest Area were to be secured and stabilized. In Burma, the Tenasserim area and the area west of the Irrawaddy River, extending from Myitkyina to Kamaing, Kalewa, Gangaw and Akyab were to be secured. The sectors having sea supply routes (Burma and Banda Sea areas), which could be attacked by enemy planes, were to be reinforced. The Palembang and Pangkalbrandan areas were also to be strengthened.
After the 55th Division occupied the area around Buthidaung, to assure the security of Akyab it was ordered to establish land supply routes immediately; strengthen sea transportation and air cover; construct additional fortifications and complete work on air bases.
The planned counteroffensive against the main enemy attack in Burma called for a powerful element to secure the strategic border area. The main Japanese body was to concentrate on the road leading from Mandalay to Toungoo and to take the offensive at the necessary points by rapid movements designed to achieve the destruction of both the Chungking and British-Indian armies. It was considered especially important to carry out a major decisive battle against units of the British-Indian Army in the Arakan Mountains. To execute this operation, special attention was to be paid to the completion of transportation facilities, fortifications and the safeguarding of important communication points. This operation was expected
to take place after the start of the dry season. The total military strength scheduled to participate in the Burma Operations was to be between six and seven divisions.
After the monsoon season, if conditions were favorable, a ground offensive was to be launched against the Tinsukia area, in northeast India. The objective of this was to cut off air transport (flying "the Hump") reinforcements for the Chungking Army.
Before the start of the monsoon season, an element of the Air Force was to carry out surprise attacks at an opportune time against the enemy Air Force surrounding Burma, while taking every precaution to minimize losses. This was to be done in an effort to destroy enemy air superiority over Burma. At the same time, the Air Force was to cooperate with offensive operations in the Akyab area.
After the end of the monsoon season the main force of the 5th Air Division was to destroy the enemy Air Force in east India. In addition, it was to cooperate with the 15th Army against the main enemy ground offensive.
Every effort was to be made to strengthen reconnaissance patrols and to equip intelligence units adequately to assist them in obtaining full information in regard to enemy strengths, movements and plans. Air and naval forces were to exert all-out efforts to frustrate attempted landings. For this purpose, as many air bases as possible were to be maintained. Independent garrison units were to
fortify and defend vital sectors where it was anticipated enemy landings would be attempted. Strategically located mobile divisions were to be moved in rapidly as reinforcements, where needed, to crush enemy landings.
Even if the situation was extremely unfavorable, the main airfields and operational bases were to be held securely to facilitate air operations and the subsequent offensive. All transportation facilities were to be used to provide necessary reinforcements to key areas. Major importance was to be placed on the protection of main communication lines from enemy air and naval attacks.
In Malaya, Sumatra and Java preparations were to be made to withstand the attacking enemy, with particular emphasis being placed on the defense of the Palembang sector. Enemy aircraft carriers and air bases were to be destroyed before the enemy could mount an offensive. All fighter plane units were to be deployed to repel enemy air attacks.
Especially in Malaya and the Philippines, mopping-up operations were to be speeded up. In the defense of north French Indo-China if the Chungking Army moved to attack, offensive action was to be taken in the important border areas and the enemy destroyed. In this, Japanese forces were to coordinate their movements with the French Indochina Army.
Troop Activities in Southwest Area Operations
In March 1943, the 54th Division was sent to Java from Japan, where it was placed under the command of the 16th Army.
In mid-January 1943, the enemy had attempted to recapture Akyab but had been repulsed. About the middle of February, the 55th Division took the offensive, defeated the enemy and occupied the area surrounding Buthidaung. There were no great changes in north and central Burma but the enemy was expected to counterattack as soon as the dry season began.
At the end of March, as the operational conditions in the Burma area became more complex, a Burma Area Army Headquarters was established and placed under the command of the Southern Army. At the same time, the 31st Division, newly organized in Thailand, was sent to Burma and placed under the command of the 15th Army.
In an endeavor to strengthen the Southeast Area at the beginning of 1943, on 7 January the 19th Army was organized and placed under the command of the Southern Army. The main force of the 48th Division on Timor and the main force of the 5th Division, on its way to the Banda Sea area, as well as other units, were placed under the command of the 19th Army. At this time, the boundary line between Dutch New Guinea and British New Guinea was designated the boundary between the 19th Army and the Eighth Area Army.
On 30 January, the 7th Air Division (composed mainly of the 3d Air Brigade) was organized in Java and entered in the order of battle of the 3d Air Army. On the same day, the 8th Air Brigade (one fighter regiment and two heavy bomber regiments) was placed under the command of the 3d Air Army. Thus the defensive strength of the important Southern Area was increased to meet the threat of the Allied Array. The enemy, however, continued attacking the sea lanes making it practically impossible to send supplies or reinforcements to the isolated islands.
Although in early 1943 the enemy was quiet in southwest China, there were indications that a strong force would soon be sent to Burma and Yunnan Province from the Chungking and Changsha areas. To cope with the heavy fighting expected in Burma with the beginning of the dry season, therefore, at the end of August 1943, the 54th Division was moved from Java to Burma.
Troop Movements in Other Areas
In order to strengthen the air preparedness in the Northeast Area, at the end of 1942, the 1st Air Division was organized and, at first, placed under the command of the 1st Air Army. In early February 1943, however, with the need to strengthen Hokkaido it was transferred to the control of the Northern Army.
Believing that the recapture of Attu and Kiska Islands by the enemy indicated plans for increased activities in the Northeast Area, the Army General Staff began to strengthen its defenses there.
On 20 May, the 7th Division was placed under the command of the Northern Army and, on the 24th, Hokkaido was placed on a wartime footing. In August, the 3d and 4th Kuril Islands Garrison Units were placed under the command of the Northern Army and deployed in the Kuriles.
In French Indo-China enemy air raids from China bases increased and it was estimated that the Chungking Army planned to advance against French Indo-China. At the end of January, the Army General Staff issued orders to the China Expeditionary Army stating that, in cooperation with the Navy, important points on Luichow Peninsula were to be attacked and occupied, as well as the French Concession on Kuangchou Bay. By 20 February, the China Expeditionary Army had accomplished this mission.36 The China Expeditionary Army then received orders to check enemy air activities and to take every opportunity to destroy the Chinese Army.
In March, the 61st Division was dispatched from Japan to central China and placed under the command of the 13th Army. In June, the 17th Division was assembled at Shanghai in preparation for shipment to the Southeast Area.
About mid-June, the 27th Division was transferred from north China to Manchuria where it was placed under the command of the Kwantung Army.
Logistical Support During the Second Phase
During this phase, as the tide of war turned against Japan and shipping losses steadily mounted, the problem of supply became more and more difficult.
In the Southeast Area, lack of ships to transport supplies and reinforcements was one of the major factors in causing units to be withdrawn from Guadalcanal, Buna and Munda. Attempts were made to transport supplies by land routes and by small landing craft fitted with guns to fight off enemy torpedo boats, but enemy planes, to a great extent, nullified this effort. It was felt that should Rabaul, the most important base in the Southeast Area, become isolated, troops in the area would be forced to be self-supporting. The Army, therefore, decided to stockpile operational material at Rabaul immediately. This plan was put into effect from the end of August to mid-November 1943 and, for the most part, was successful.
With the fast deteriorating situation in the Southeast Area, it was vitally necessary for western New Guinea and the Moluccas to be reinforced. The Army General Staff, therefore, ordered the Southern Army to establish a base in the Halmaheras.
The Southern Army's plan in regard to logistical support of its army had at first gone very smoothly but, with adverse developments in the Southeast Area, it became increasingly difficult to send supplies from Japan. An attempt was made, therefore, to establish a
special transportation route from the Southwest Area to the Southeast Area. Ships from Japan destined for the Southeast Area via Palau were ordered to use the Philippines' harbors as relay points, thus making the Philippines an extremely important intermediate base between the two areas.
Third Phase of the War (September 1943 - June 1944)
Part 1, First Stage (September 1943 - February 1944)
Situation Review and Estimate of Enemy Plans
Until the summer of 1943, Imperial General Headquarters and the Japanese Government had based their direction of the war on the "General Outline of the Future War Direction Policy" adopted on 7 March 1942. This general outline had been determined when the first stage of the operations in the Southern Area was successfully completed. Its basic aim was to force Britain and the United States to cease hostilities. Reverses, both militarily and politically, now forced a fundamental revision of this policy.
Militarily, the American counteroffensive had far surpassed anything Imperial General Headquarters had anticipated both in its tempo and scope with the result that all attempts to expand early successes failed and, to a large extent, Japan lost its fighting power. Politically, an unfavorable situation had been created by Italy's capitulation after the withdrawal of German and Italian troops from North Africa, In addition, the critical situation in the Southeast Area combined with heavy shipping and aircraft losses, demanded a complete review of the total war picture and a revision of the basic operational plan.
On 30 September 1943, an Imperial Conference was convened and, after discussion, final plans for the new "General Outline of the Future War Direction Policy" was adopted. General details regarding adjustments in military and governmental policies are included in the following text.
Imperial General Headquarters estimate of the enemy situation in September 1943 was that the Allied Powers' counteroffensive would become increasingly intense. The Allied offensive against the Axis powers would reach its peak between the latter part of 1943 and the spring and summer of 1944. The enemy would also attempt to tighten the circle around Japan from both the southwest and northeast and would step up its air and sea attacks against key positions in important occupied areas. Enemy planning appeared designed to terminate the war in the Far East as quickly as possible.
In China, the Nationalist Army in Chungking would continue to resist, while Allied air activities in China would be expanded and intensified.
The chances of avoiding war with Russia continued to be favorable. At the same time, the possibility of the United States being provided with air base facilities in eastern Siberia could not be overlooked.
The Anglo-American front line strength around Japan in September 1943 was estimated to be approximately 2,400 aircraft and 23 divisions. The total strength, including reserves, was believed to
be in the vicinity of 6,000 aircraft and 70 to 80 divisions. An estimate of disposition of enemy strength was:
Air Force Strength
(Approx. No. of Planes)
Ground Force Strength
(Approx. No. of Divisions)
Area Front Line Total Strength Front Line Total Strength Northeastern area 300 800 3 6 Central Pacific area 200 1,000 --- 3 Southeastern area 1,300 3,000 10 33 Southwestern area 600 1,000 10 37 Total 2,400 5,800 23 79
Enemy reinforcements in the Pacific Theater would depend largely on the scale of the second front to be created in Europe. Other influences would be the enemy shipping situation and the degree of progress of the armament expansion program in the United States. Indications were that priority would continue to be given to the counteroffensive in Europe. Taking these factors into consideration and assuming that the ships now available for the Pacific Theater would total two million tons with an increase during the ensuing year of from four to five million tons, the rate of increase in enemy strength was estimated to be:
Air Force Strength
(Approx. No. of Planes)
Ground Force Strength
(Approx. No. of Divisions)
Period Front Line Total Strength Front Line Total Strength End of 1943 4,000 7,700 35 90 to 100 Middle of 1944 5,300 9,000 43 100 to 110 End of 1944 7,000 12,000 60 110 to 120
The main force of the United States Navy was operating in the area between Hawaii and the Southeast Pacific area and was organized into several naval task forces. The main force was believed to include approximately 6 aircraft carriers, 15 battleships and 15 cruisers. In addition, small surface forces, each composed of several warships, were operating in the Alaska-Aleutian area and in the vicinity of Australia. Approximately 10 converted aircraft carriers were engaged in escorting convoys to the Southeast Area.
It was estimated that the United States would have about 12 aircraft carriers by the end of 1943, to be increased to about 16 by the middle of 1944 and to 18 by the end of that year. It was known, however, that shipbuilding in the United States was progressing well and it was considered very probable that their carrier strength might increase even faster than this estimate.
The British Navy was operating in the west Indian Ocean with 1 aircraft carrier, 2 converted aircraft carriers, 4 battleships
and 10 cruisers as its main strength. Italy's capitulation made it probable that this force would be reinforced by 4 or 5 carriers, a few converted carriers, 2 or 3 battleships and 10 cruisers from the European theater.
Approximately 80 United States submarines were operating out of bases at Hawaii, Dutch Harbor (Aleutians), Brisbane and Perth (Australia) and some ten British submarines were using Ceylon as their base.
It was estimated that during the latter half of 1943 and through the following year the enemy would push offensives from both the east and west in an endeavor to capture such strategic points as Rabaul in the Southeast Area and Burma, Andaman, Nicobar and Sumatra in the Southwest. As part of the over-all Rabaul Area Operations, following the capture of Rabaul the enemy would direct assaults against the South Pacific Mandated Islands and the Philippines. The enemy would also endeavor to invade the Kuril Islands and the Banda Sea area; attempts would be made to disrupt sea communications and repeated bombing of Japan and the occupied areas obviously would be part of their plan.
Considering the current available carrier force strength, the probability of large-scale enemy assaults against the Central Pacific Islands was considered unlikely. Toward the end of 1943, however, attempted invasion of the Gilbert and Nauru Islands or Wake and Marcus Islands, in conjunction with attacks on Rabaul, seemed very probable.
Army General Staff Operational Plan Changes
After careful consideration of this estimate, Imperial General Headquarters recognized the necessity to change its operational policy. On 15 September, therefore, the Japanese Army, in close cooperation with the Navy, was ordered to direct operations in accordance with the following plan:
1. In the Central and Southern Pacific Areas, the enemy forces attempting to invade the strategic districts of the Southeast Area remaining in our hands will be destroyed. Construction of defenses will be completed and the strength necessary to deliver counterattacks will be disposed along a line extending from the Banda Sea to the Caroline Islands. If possible, the initiative will be taken and invasion of the area prevented.
2. In the Southwest Area, the positions remaining under our control will be held at all costs. For this purpose the complete destruction of the enemy advancing in the Burma, Andaman, Nicobar and Sumatra areas is essential.
3. In China efforts will be made to stabilize and generally retain those areas now occupied and, by increasing pressure against the enemy, efforts will be directed toward destroying their will to fight. In Manchuria preparations for battle will be expanded extensively as a deterrent to Soviet-American cooperation. If at all possible, war with Russia will be avoided.
4. In the defense of the Homeland, oilfields in the Southwest Area and sea communications will be strengthened to the utmost to facilitate the conduct of war.
5. On every front raiding operations will be conducted deep into the enemy rear.
6. Every measure will be taken to bring into full play the combined fighting power of the Army and Navy, especially their air power and sea transportation capacity.
The main reason for the change in operational policy was that, in spite of the tremendous effort that had been made to hold the strategic areas along a line extending through eastern New Guinea, the northern Solomons and the Marshall Islands, this line was on the verge of collapse. This would neutralize the forces at Rabaul and weaken the position of those on the Marshall and Gilbert Islands. Even with reinforcements there was little hope of holding this area for any length of time. It was, therefore, deemed advisable to pull back to a line extending from the Banda Sea through the eastern and western Carolines to the Marianas. All possible strength was ordered to be used in defending this line.
As a consequence of this change in policy subsequent operations in the Southeast Area were to be conducted as delaying actions and, as a result, some 300,000 men eventually were isolated at Rabaul and other areas in the Southeast Area.
On 30 September 1943, a Council in the Presence of the Emperor was held and Imperial General Headquarters' new operational plan was approved, with special emphasis being placed on a rapid increase in plane production. It was decided also to move for mediation between Germany and the Soviet Union in an effort to achieve peace and, at the same time, to tighten ties with Germany within limits that would avoid provoking the Soviet Union.
Further Survey of the Situation
The enemy, with its superior air power, now had command over the Solomons and New Guinea and, despite stubborn resistance and courageous fighting on the part of the Japanese forces, the war situation could only be regarded with deep pessimism.
It was believed that the United States Army had completed its base on Munda in the Solomons during September 1943. In late October United States forces had landed on Mono, off Bougainville. Also in September the area around Finchhafen in New Guinea had been occupied. On 1 November, United States troops landed in the vicinity of Torokina on Bougainville Island. During November a naval battle raged off the shores of Bougainville, in addition to five great aerial battles, during all of which the Japanese had suffered severe losses. On 21 November, the enemy attacked Makin and Tarawa in the Gilberts and, by the 25th, had annihilated the Japanese naval land units there. During the second half of December the enemy made several landings on New Britain. On 1 February 1944, they attacked Kwajalein and Roi in the Marshalls and, by the 6th, had destroyed the Japanese naval land units. On 17 February, an enemy carrier task force struck at Truk and inflicted heavy losses on the ships anchored there. The United States Navy in the Central Pacific was extremely active and the situation in that area was critical. On 29 February, the enemy landed on the Admiralties.
At the end of Januarya British force of about two divisions launched an offensive against the Japanese 55th Division in the vicinity of Buthidaung and Maungdaw, in the southwest coastal area of Burma. Although the Division fought back galla
ntly, it was forced to withdraw. Early in February, the newly activated Chinese Nationalist 1st Army advanced from Assam to the Hukawng Valley where it engaged the 18th Division.
The numerous penetrations made by the enemy in the different sectors in the Southeast Area had greatly weakened the effectiveness of the Eighth Area Army. With the decline in naval strength and the Army being constantly forced back, further planning for campaigns in this area appeared useless.
On 8 September 1943, Italy surrendered. This not only greatly affected the European situation but, in addition, would release further enemy strength for the Pacific theater. In November and December the United States, Britain, U.S.S.R. and China held the Cairo and Teheran Conferences.
In the Far East in September and October the following political agreements were concluded: The Burma-Japan Alliance Pact; the Declaration of Independence of the Philippine Republic; the Philippine-Japan Alliance Pact; Establishment of the Government of Free
India;37 the China-Japan Alliance Pact.
Within Japan, in September 1943, the Ministry of Munitions was established and, in February 1944, General Tojo was appointed Chief of the Army General Staff and Admiral Shimada, Chief of the Navy General Staff.
Southeast, North of Australia and Central Pacific Areas Operational Strategy
In accordance with the Central Agreement of 30 September 1943, the Army General Staff issued the necessary orders to the Southern Army and Eighth Area Army for future operational guidance.
The plan for operations in the Central and South Pacific Areas called for a prolonged tactical war in the important regions of the Southeast Area and the construction and strengthening of bases in the North of Australia Area. In addition, one or two divisions were
to be dispatched to that area to prepare to check the enemy's advance. The Eighth Area Army was ordered to cooperate with the Navy in checking the enemy in important sectors of the Southeast Area, and the Southern Army to cooperate with the Navy in expanding preparations for counterattacks in the North of Australia Area.
On the same day the Central Agreement was concluded, each responsible Army commander received orders in regard to his particular objectives. The general over-all objectives of the plan included the following four points:
1. The enemy advancing on the front extending from eastern New Guinea to the northern part of the Solomon Islands in the Southeast Area will be crushed while an all-out delaying action will be carried out.
2. By spring of 1944, defenses for the operational bases in important regions extending through the North of Australia Area and the Caroline and Mariana Islands will be strengthened. Operational bases will be constructed in the Philippines. Preparations for counterattacks by the Army and Navy air, ground and surface forces will be speeded up.
3. In order to defeat any offensives launched by the enemy on its principal fronts, bases in the abovementioned zones will be used as fortified positions in coordinated counterattacks by the forces of the various branches of service.
4. If the over-all situation permits, an offensive will be launched from the North of Australia Area after the middle of 1944. The direction of this offensive will be decided after special studies and necessary preparations have been made.
In the North of Australia Area, in the spring of 1944 the Army and Navy were to cooperate in expediting preparations for operational bases, strengthening defenses, stockpiling war supplies, increasing shipping and constructing lines of communications. These preparations were to be carried out in conjunction with defensive actions in the area. The war situation in the Southeast Area made it urgently necessary to complete preparations as quickly as possible.
In the Central Pacific Area, the Navy was ordered to complete operational preparations in the Caroline and Mariana Islands by the spring of 1944. Necessary Army units, together with part of a line of communications unit, were to be dispatched to the Central Pacific Area, where they were to coordinate with the Navy in expediting these operational preparations. Upon arrival, these units were to be placed under the command of Navy officers.
Army General Staff directives were issued to Army commanders in regard to carrying out orders in accordance with the Central Agreement. The principles of these directives were to be followed in operational preparations which it was expected would be completed about spring of 1944. It was estimated the entire project would be completed about the middle of 1944. Some of the more essential matters to be completed were: construction of air bases; deployment of essential troops; increase in reconnaissance and patrolling against the enemy; construction of fortifications; stockpiling of munitions;
establishment of shipping bases and small boat transportation routes along the coast; installation of communication apparatus and a general bolstering of the system for self-subsistence in the occupied areas.
Allocation of areas of responsibility for the supply system provided that the Halmaheras would serve as an intermediate supply base for the Banda Sea area and northwest New Guinea. The terminal points for supplies from the Homeland and the Southern Army would be Sorong for the Banda Sea area; Manokwari for northwest New Guinea, and Makassar for the Flores Sea area.
During the latter part of October 1943, to strengthen the defenses in the Central Pacific area, Imperial General Headquarters sent the 52d Division from Japan to Truk. On 16 November, the 1st Amphibious Brigade and the 1st through 5th South Pacific Detachments were placed under the command of the 4th Fleet commander and the 6th South Pacific Detachment under the Eighth Area Army commander. All of these units were deployed throughout the various islands in the Central Pacific Area.
In early February 1944, the 29th Division was sent to Saipan from Manchuria.
Until early February the progress of defensive preparations in the South Pacific Area had been proceeding according to plan but with the isolation of the Eighth Area Army and the fall of the Gilbert Islands it became necessary to speed up these preparations.
On 25 February 1944, the 31st Army was activated and ordered to direct all Army forces in the Central Pacific Area. On the same day its order of battle was issued to include:
31st Army Headquarters
29th Division (Guam)
52d Division (Truk)
1st Amphibious Brigade
South Pacific Detachments
(1st, 2d, 3d, 4th and 5th)
South Pacific Garrison Units (2d and 3d)
Chichijima Fortress Unit
5th Independent Mixed Regiment
(1st, 2d, 3d, 4th, 5th, 6th, 7th and 8th)
The 1st through 8th Expeditionary Detachments were units which had been organized in a hurry and transferred from Manchuria and Korea. Each of these detachments was composed of from three to six infantry battalions, one artillery battalion, one engineer company and service units.
Army-Navy Central Agreement on Central Pacific Operations
On 25 March 1944, Imperial General Headquarters issued the Army-Navy Central Agreement on the Central Pacific Area Operations. Its operational objective was to destroy the invading enemy and thus to deny the Allies bases from which they could mount counteroffensives against the Central Pacific Area.
The Army and Navy were to cooperate closely in speeding up the completion of preparations for this operation.
By the spring of 1944 the Navy was to complete operational preparations in the Caroline, Mariana and Ogasawara Islands. The Army was to cooperate with the Navy in preparing and carrying out ground operations by sending the necessary units to the Central Pacific Area and placing them under the command of appropriate Navy Officers.
The 31st Army commander was to be placed under the command of the Central Pacific Area Fleet commander and to direct ground operations, chiefly in the central and western Carolines, in the Marianas and in the Ogasawaras. The senior commander on each island was to assume the over-all command of ground units (air defense units excluded) in ground combat.
The Army was to be responsible for the dispatch and transportation of Army forces to the Central Pacific Area (including transportation of supplies and materials sufficient for a minimum of three months) and the Navy was to be responsible for the transportation of regular supplies (replacements included) additional supplies and materials and the evacuation of patients. Adjustment between the Army and Navy concerning supplies and other items was to be made by Imperial General Headquarters.
Involved discussions were held before a final decision was reached on the Central Agreement. While preparations were being made to issue orders for the 31st Army, according to the tentative agreement
on unified operations under the command of the Navy, in mid-February the Navy requested that the Army strength in the Central Pacific area be kept separate and that the operations be carried out by normal cooperative methods between the Army and Navy. The Army authorities, however, insisted that the original plans be adhered to for a number of reasons. As the operations in the Central Pacific were regarded as extremely important, it was necessary to coordinate the entire Army and Navy strength in the area. The Navy Air Force was to be the main defensive force but the Army would have to hold the airfields which the Navy Air Force would use. Operations on Attu, Kiska and Guadalcanal had clearly demonstrated that it was absolutely essential that in operations of this kind the Army and Navy should operate under a unified command. Further, it would be most difficult for the Army units on the islands to carry out their missions without receiving a great deal of assistance from the Navy in regard to transportation, escort, supply, intelligence and communications.
These arguments were finally recognized by the Navy.
Operational Preparations in the North of Australia Area
In late November 1943, in order to establish a functional command and complete operational preparations in the area North of Australia, Imperial General Headquarters transferred the headquarters of the Second Area Army from Manchuria to Davao in the Philippines.38
The 2d Army (mainly the 36th Division) and the 19th Army (5th, 46th and 48th Divisions) were placed under the command of the Second Area Army and the Area Army was assigned the mission of repelling the enemy in the North of Australia Area and holding the strategically important points in the area. The operational boundary line between the Eighth Area Army and the Second Area Army was Long. 140°E; between the Second Area Army and the Southern Army it was a line connecting Makassar Strait and Lombok Strait and between the Second Area Army and the 14th Army Lat. 5°N. The important strategic areas to be held were western New Guinea, Aroe, Tanimbar, Timor and the Lesser Sunda Islands.
The Second Area Army headquarters which had arrived at Davao in mid-November, assumed command of it's area on 1 December. Later, it moved to Manado.
Prior to this, the 36th Division had been transferred from China to the North of Australia Area in mid-October and placed temporarily under the command of the 19th Army commander. The 46th Division was transferred from Japan to Soemba Island where it was placed temporarily under the command of the 16th Array commander. In addition, the 7th Air Division, already in the area, was placed under the operational command of the Second Area Army.
On 10 February 1944, the 14th Division awaiting shipment from Manchuria to the North of Australia Area, was placed in the order of
battle of the 2d Army. With the urgent necessity to strengthen Palau, however, while this division was still en route its destination was changed to Palau.
Efforts to Strengthen Shipping and Transportation
From the beginning of the war the number of transports sunk had far exceeded estimates and as the war continued the number sharply increased until the situation grew critical.
In December 1942, the Army General Staff had first presented a recommendation that it be allowed to requisition an addition 300,000 tons of available civilian shipping facilities. As a general rule, the War Minister, in his position as a member of the Cabinet, supported all requests made by the Army General Staff. On this occasion, however, he firmly refused to support this recommendation because of his views regarding the over-all total economic picture. The Army General Staff, although it constantly stressed its belief that shipping requirements for immediate operations should be given priority, each time found it necessary to submit further requests for shipping to carry out its planned operations. On every occasion it had to overcome strong opposition to obtain even part of the required shipping. It continued its efforts to obtain ships but only small gains were realized.
Imperial General Headquarters had planned to greatly increase shipping units and strengthen defensive measures to protect shipping.
Sea escort (Navy responsibility) and the area around the ports (Army responsibility) were to be reinforced by increasing fire power and adding the necessary air force units, especially in the areas where the enemy had air superiority.
During the latter half of September 1943, the Army General Staff carried out a reorganization and strengthening plan for its shipping units. These reorganized units were stationed at Ujina, Shanghai, Singapore, Rabaul, Halmaheras and Otaru. For the most part, the added strength was gained through consolidation of units from other areas, plus special attention to the development and addition of small craft (such as landing craft and small fishing boats), as means of transporting supplies in the local areas. In the latter part of December further reinforcements were accomplished in this manner.
Losses to submarines on the main routes between Japan and the Southern Area (Japan to Formosa and the Philippines and from the Philippines to French Indo-China and Malay) were heavy. Losses suffered in the Central Pacific Area were severe but not quite so great. Furthermore, shipping losses from enemy air actions were rapidly increasing. The Army and Navy, therefore, were ordered to make a joint study of ways and means to protect shipping.
On 1 November 1943, the China Expeditionary Army commander and the 14th Army commander were ordered to have their air units cooperate with the Navy in anti-submarine operations. In mid-February 1944,
the air units of the Northern Army (1st Air Division) were deployed in the Kushiro, Nemuro and Muroran areas and the Tsugaru and Soya Straits while elements of the 1st Air Army were based in southern Kyushu, the Southwestern Islands and Formosa. In addition, the commander of Homeland defenses was ordered to reinforce protection of sea transportation in the vicinity of the Korean Strait with air units from the Western Army Command and the Korea Army.
Strengthening Sea Bases
Shipping losses around the Solomons and New Guinea, where the enemy had definite air superiority, were extremely high and Japanese losses from both air and sea attacks daily increased. On 15 February 1944, therefore, the Army General Staff directed the Southern Army commander, the Second Area Army commander and the Northern Army commander to take special precautions to protect the sea bases in the Bay of Bengal, the North of Australia Area and around the Kuril Islands. This was vitally necessary not only to protect sea movements and make counter operations easier but also to maintain supply lines to strategic points around the perimeter. Everywhere there was a growing awareness of the vital necessity to fortify harbors and bases against air and sea attacks.
The items most necessary to be installed at the bases were: shelters for small boats; small boat maintenance units; communication installations; base units - antiaircraft, if possible; navigation markers; line of communications installations, and stockpiles
of munitions and fuel. The sea bases were to be classified as sea combat bases and sea line of communications bases and were to be used by torpedo boats and those forces which were to take part in short range sea combat. They were also to be used as standby and assembly points for amphibious groups.
Enemy attacks on shipping had compelled the use of rail transportation wherever possible. The railroads of Korea, Manchuria, China, French Indo-China, Siam, Malaya end Burma, therefore, had to be improved and, on 10 February 1944, the Army General Staff published a plan for the reorganization and reinforcement of railway units to strengthen railway transportation.
Approval to Undertake the Imphal Operation ("U-GO" Operation)
It was recognized that Burma was not only of great value as the northern wing of the Southern Area but that both strategically and politically the cutting of the Burma Road would be of great significance. The Army General Staff and the Southern Army regarded this area as an extremely important one and, since it was believed that both the British and the Chinese Armies would use their main forces in this area, planned to reinforce its strength. In November 1943, the 53d Division was ordered to leave Japan for Burma where it was to come under the command of the Southern Army commander. At the beginning of 1944, the Burma Area Army commander had under his command the 15th Army (15th, 18th, 31st, 33d and 56th Divisions), the 28th Army (2d, 54th and 55th Divisions) and the 24th Independent Mixed Brigade.
At the end of December 1943, the Southern Army commander had sent his Assistant Chief of Staff to Tokyo to recommend to the Army General Staff that the "U-GO" Operation be undertaken. After the completion of the first stage of the Southern Operations many studies had been made in regard to this operation and the Southern Army commander strongly recommended that it now be launched. The operational plan called for using three divisions under the 15th Army to attack from the east and south during the spring of 1944, with its objective being annihilation of the enemy in the Imphal Basin.39
The Army General Staff first required the Southern Army commander to answer the following questions:
1. Could the Southern Army deal successfully with an Allied seaborne attack from the Bay of Bengal in the midst of the "U-GO" Operation?
2. In view of the increased length of the front which would result from the occupation of Imphal, was there sufficient strength to guarantee the continued defense of Burma?
3. Could the small Japanese air force keep pace with the ground forces and support them throughout the operation?
4. Was the supply position satisfactory?
5. Could the 15th Army's plan be relied on? The Southern Army representative answered that he was confident of success.
On 7 January 1944, the "U-GO" Operation was approved and the necessary directives issued. As an operational method in the defense of Burma, the Southern Army commander was authorized to launch an offensive operation against the important area of northeast India centering around Imphal. After crushing the enemy, he was to secure this area.
On 8 March, the "U-GO" Operation began with the advance of the Division.
Directives for "ICHI-GO" Operation
By the fall of 1943 the ever-present threat of the enemy air force striking Japan from the interior of China, its constant harassing of water transportation and the destruction of lines of communications between Japan and the Southern Area made an operation against the interior of China imperative. Imperial General Headquarters ordered plans to be drawn up for the capture of strategic points along the Hunan-Kwangsi, Canton-Hankou and southern Peiping-Hankou railways. The operation was to be known as "ICHI-GO" and the four main objectives were:
1. The capture of potential United States B-29 bases at Kweilin and Liuchow.
2. Countermeasures against enemy activities in south China to prevent the enemy moving into south China via India, Burma and Yunnan.
3. As sea transportation was rapidly deteriorating, the railroad running north and south via French Indo-China was to be repaired and a reliable land transportation system for the Southern Army was to be established.
4. Every effort was to be exerted to weaken the Chungking Government by crushing the Nationalist Army.
After a number of conferences it was decided that emphasis was to be placed on the capture of Kweilin and Liuchow airfield. Toward the end of January 1944, Imperial General Headquarters approved the plan and ordered the Commander in Chief of the China Expeditionary Army to execute the operation. The Southern Army was ordered to support the China Expeditionary Army.
On 24 January, the following order was issued to the Commander in Chief of the China Expeditionary Army:
Imperial General Headquarters desires important enemy bases in southwest China destroyed.
The China Expeditionary Army will seize important areas along the Hunan-Kwangsi, Canton-Hankou and the southern Peiping-Hankou railways.
Imperial General Headquarters also published an outline of the plans for the China Expeditionary Army and Southern Army's operations and strongly stressed the importance of observing the utmost secrecy during preparations for the operations.
An outline of the conduct of the operations in the various areas stated:
The North China Area Army will begin its operation about April 1944. It will destroy the enemy, especially the main force of the 1st War Sector Army and capture and secure the areas south of the Huang Ho and along the southern Peiping-Hankou railway.
The period for this operation is estimated to be about one month and a half.
The forces to be employed will be the 12th Army (composed mainly of four divisions) and part of the 5th Air Army.
Upon completion of this operation the necessary forces will be transferred by land to the Hunan-Kwangsi operational area by way of the Wuchang-Hankou sector.
The newly occupied area will be secured by approximately two divisions.
The 11th Army will commence its operation from the Wuchang-Hankou area about June 1944, while the 23d Army will commence its operation from the Canton area about July or August.
These armies will destroy the main force of the 6th and 9th War Sector Armies. After the Kweilin and Liuchow areas have been captured, both armies will mop up the remaining hostile troops in the areas along the Hunan-Kwangsi and the Canton-Hankou railways and will occupy and secure these areas.
The period for this operation is estimated to be approximately five months.
Depending upon circumstances, air bases in the Suichuan and Nanhsiung areas may be destroyed.
About January or February 1945, the 23d Army will capture Nanning and its vicinity. It will also secure the road between Kweilin and Langson.
Prior to the 11th Army operation, the entire force of the 5th Air Army will annihilate the United States-Chinese Air Force and attain air supremacy in order that it might cooperate directly with ground operations whenever necessary.
The forces to be used during this operation are:
11th Army - seven or eight divisions
23d Army - two divisions
Units under the direct command of the China Expeditionary Army - one or two divisions 5th Air Army - two air brigades
The occupied areas along the Hunan-Kwangsi and the Canton-Hankou railways will be secured by approximately eight divisions and four brigades.
Southern Army Cooperation
In order to facilitate the operations of the China Expeditionary Army, at an opportune time the Southern Army will carry out an operation on the Lu Chiang (Salween) front and restrain the enemy in the Yunnan area.
If circumstances permit, part of the Southern Army will advance from Langson and cooperate with the China Expeditionary Army in capturing the Nanning area.
During the air operation, at least one air brigade of the 3d Air Army will cooperate with the 5th Air Army.
The critical position in the Pacific area compelled Imperial General Headquarters to transfer some of its more highly trained
divisions from China and Manchuria to the Pacific area. At the same time, every effort was made to reinforce the China area in preparation for the "ICHI-GO" Operation. The substitutions, transfers and reinforcement of forces in that area from early February until the commencement of the operation were:
The 32d and 35th Divisions of the 12th Army, North China Area Army, were transferred to the Pacific area. The 27th Division, Kwantung Army was assigned to the China Expeditionary Army, which in turn placed it in the order of battle of the 11th Army. Within the China Expeditionary Army the 37th, 62d and 110th Divisions and the 3d Armored Division were reattached to the 12th Army from the 1st Army, North China Area Army and the Mongolia Garrison Army respectively. The 116th and 22d Divisions of the 13th Army were attached to the 11th and 23d Armies respectively. The 39th Division and 17th Independent Mixed Brigade of the 11th Army were placed under the direct command of the China Expeditionary Army but still remained under the tactical command of the 11th Army.
During March, 14 independent infantry brigades were organized and attached to the various armies in China and, in early May, field replacement units were attached to the various armies.
In mid-February, the 3d Air Division Headquarters in China was redesignated the 5th Air Army Headquarters, while in March the necessary air maintenance and supply units were established in China.
The area covered during this operation was estimated to be approximately 1,500 kilometers. Approximately 400,000 men, 70,000 horses and 12,000 vehicles were used. There were many difficulties to be overcome during the conduct of the operation, two very important ones being lack of gasoline and ships. This led the Army General Staff to order that as few ships as possible would be used during the preparation period for the operation, especially larger type ships. However, inland water transportation was to be used as much as possible in order to curtail the use of land transportation. Extensive use was to be made of local resources and captured materials. Railroads were to be repaired as quickly as possible. Hospitals in China and Manchuria were to be enlarged and every effort made to eliminate such tropical diseases as malaria. When no longer essential for the main operation, all available motor transportation was to be collected and made ready for operations in other areas.
In accordance with plans, on 17 April and 27 May respectively, the Peiping-Hankou and Hunan-Kwangsi Operations began.
Directives for Various Areas
When Italy surrendered on 8 September 1943, the Army General Staff immediately issued orders to the commanders of the China Expeditionary Army, the Southern Army, the 14th Army and the Governor General of Hong Kong to halt all Italian activities in their operational areas and to disarm all Italian forces. These forces included some Italian naval landing units stationed at Shanghai and Tienching, the consulates in China, Thailand and French Indo-China, as
well as a small number of merchant ships and Italian nationals in China, the Southern Area and the Philippines. Orders were also issued to place all Italian nationals under close military administrative surveillance.
In an effort to strengthen the forces in the Southwest Area, in late September 1943 the 4th Division (stationed in Japan) was placed in the order of battle of the 25th Army. On 10 December, the French Indo-China Garrison Army was reorganized, its main strength being the 21st Division and the 34th Independent Mixed Brigade. On the same day, the Thailand Garrison Army was organized with the 29th Independent Mixed Brigade as its main unit. In mid-January 1944; the 29th Army, composed of a number of independent garrison units, was organized and ordered to defend northern Malaya.
To strengthen the defenses of the oilfields in Sumatra, in January 1944, the 9th Air Division was activated and placed under the command of the 3d Air Army. At this time, the Bangkalangbrandan Defense Unit and the Palembang Defense Unit were placed in the order of battle of the 9th Air Division.
To strengthen the defenses of the Homeland and Korea, in early January 1944, 7 guard units, 55 special guard units, 64 special guard companies and 15 special guard engineer units were organized and placed under the command of the appropriate commanders.
The 42d Division was transferred to the Kuril Islands and there placed under the command of the Northern Army commander.
Additional Construction and Maintenance Plans for Air Bases
Having learned from past experience that the best defense in amphibious defensive operations was obtained when the air units were disposed in a network of air bases along the main line of defense, in late January 1944 orders were issued to construct and maintain air bases to cover the entire defensive zone by the end of 1944. The main purpose was to coordinate and perfect air defense by grouping airfields into a system of centrally organized air bases. A concentrated air defense could thus be mounted quickly and effectively. For proper functioning of the system, effective communication, repair and supply systems would have to be provided. Positions were to be located in depth in accordance with the ground force operational area policy. Locations would be decided in relation to the already established air bases in the front lines of the outer defensive sphere. In addition, emergency fields and air strips to support the military air routes were to be constructed as speedily as possible.
Part 2, Second Stage (March - June 1944)
Situation Review and Estimate of Enemy Plans
With the fall of the Admiralty Islands, the Allies now dominated the sea in this area and the Eighth Area Army Headquarters at Rabaul was completely isolated. Sea transportation to the 18th Army in eastern New Guinea which had been extremely difficult for some time, by late April, after the enemy landed at Hollandia and Aitape, became almost impossible. During the second half of May, the enemy landed on Sarumi and Biak Islands. This move entirely cut off eastern New Guinea from the North of Australia Area.
In Burma, on 15 March, the 15th Army commenced to cross the Chindwin River, in accordance with the "U-GO" Operation plan. The operation took the enemy by surprise and, at first, proceeded smoothly. By 6 April, the 31st Division had captured Kohima and the main force of the 15th Division had advanced to the north of Imphal. Units from the 15th Division cut the road between Kohima and Imphal and the 33d Division, approaching from the south enveloped British-Indian troops at Tiddim and Tonzang.
Enemy resistance, however, proved stronger than had been anticipated. In May, the rainy season began, preventing supplies of food and munitions from reaching the 15th Army, while enemy air superiority permitted support of its units by air drops. In June the 15th Army was forced to withdraw.
In the Hukawng River Valley area, at the beginning of March, in the face of a superior enemy, the 18th Division was forced to withdraw gradually to the north of Mogaung. In an attempt to intercept the Division's line of retreat, the enemy landed parachute troops in the vicinity of Katha and Mohnyin. This force immediately built an airfield and constructed perimeter positions around it. The Southern Army issued orders to the Burma Area Army to destroy this force but, due to transportation difficulties, the Area Army was unable to assemble sufficient strength at any time to overcome it. The Southern Army transferred the 53d Division from Malaya as additional reinforcements but the airborne raiding force, which was being supplied by air, continued to resist until early May when it began to withdraw to the north of Hopin.
During the latter part of March, the Allies attacked Palau and inflicted heavy damage on the ships in the vicinity of the island. On 15 June, powerful enemy land, sea and air forces began an offensive operation against Saipan and, by early July, had annihilated the defending force and captured the island.
On 19 and 20 June, the 1st Mobile Fleet engaged the United States Fleet off the Marianas in the largest naval battle fought in the Pacific War. Although some damage was inflicted on the enemy, the Japanese Navy suffered tremendous losses. Of the 360 Japanese carrier-borne aircraft employed in the action, only 25 survived. In addition,
the greater part of its base air force was lost. Out of the nine aircraft carriers employed, three were lost and four damaged. Although no battleships or cruisers were sunk, because of the trend of modern naval battles the loss of the aircraft carriers proved an almost fatal blow to the Japanese Navy. With the loss of the decisive aerial and naval battles, the Marianas were lost.
In China, in mid-April, the first phase of the "ICHI-GO" Operation had been opened according to plan and, by 9 May, the 12th Army in north China had successfully completed the Peiping-Hankou Railway Operation. The Hunan-Kwangsi Operation, which was the second phase, was begun toward the end of May.
Suddenly, on 16 June, the United States Air Force based in China made its first air raids on the Homeland on the Shimonoseki-Moji and Yawata-Kokura areas of northern Kyushu.
In Europe, on 6 June, the Allies commenced landing operations to open the second front and the Germans were unable to launch an effective counterattack.
After the conclusion of the first stage of the first phase of the Southern Operations in June 1942, the Japanese Army had made preparations for defensive warfare, expecting enemy attacks from any of the following directions:
- From the Aleutians against the Kuril Islands
- From the Central Pacific against Japan or Formosa and the Philippines
- From New Guinea against the Philippines via the North of Australia Area
- From the Indian Ocean against Java and Sumatra
- From Burma toward Malava and Thailand
Upon reviewing the situation about July 1943, it had been assumed that in all probability the attacks would be mounted by the Americans from the Pacific area and by a combined force of Americans, British and Chinese from Burma.
Since late 1942, the enemy had successfully attacked the Southeastern Area, advancing their bases step by step. After the attack on the Gilbert Islands in the autumn of 1943 and the attacks against the Marshalls and Truk in February 1944, they changed their tactics and, using the strength of their fleet, began leapfrog operations. It was strongly evident at this time that the immense matériel power of the enemy was fast becoming one of the deciding factors in the conduct of the war.
It was difficult to judge whether the enemy would attack Japan directly or first invade the Philippines and Formosa. Considering the strategical value of the Philippines and the difficulties involved in making a direct attack against Japan, it seemed highly probable that the enemy would first attack the Philippines. Should this maneuver prove successful, the Southern Area would be cut off entirely from the rest of the Empire. It was estimated that should the enemy decide on the latter course it would first conduct a diversionary operation in the Kuril area. Further, the enemy might
attack the Philippines and Formosa from the direction of the Marianas, or the southern Philippines from the direction of New Guinea and the North of Australia Area, The latter course appeared to be the more logical.
Contributing to the problems in the Burma-Thailand-French Indo-China area was the weak position of Japan in Thailand and French Indo-China. In each of these countries, Japan was operating by mutual agreement with the governments concerned as in neither country had a military administration been established. The presence of Japanese troops was based entirely on diplomatic agreements, but with the unfavorable trend of the war, it was felt that these agreements might not be sufficient to obtain the required support of these countries. This unstable political situation could easily have a very unfavorable effect on the situation should the enemy counterattack through Burma, If an attack were successful, it was anticipated that it would encourage the Chinese to greater efforts against the Japanese forces in China proper.
In addition, with the favorable Allied situation in Europe it was expected that the United States would concentrate greater strength in the Far East and that a decisive campaign was close at hand.
Having considered all these circumstances, it was decided that the Army would continue to carry out the operational plan established in September 1943. Greater efforts, however, would have to be
exerted toward reinforcing defensive positions in the Central Pacific establishing defensive positions on Formosa, the Nansei Islands and the Philippines; strengthening the defense of the Homeland; bolstering the protection of shipping; increasing the production of airplanes, and conducting research on and producing radar equipment.
North of Australia Area Directives
Realizing that it was virtually impossible for the Eighth Area Army commander isolated at Rabaul to command the 18th Army in New Guinea, on 14 March 1944, the Army General Staff issued orders for the 18th Army and the 4th Air Army to be transferred from the Eighth Area Army to the Second Area Army.
The missions of the Second and Eighth Area Armies were revised as follows:
The Army General Staff plans to hold Rabaul and the Marshall Islands as long as possible, and will establish fortified positions from which to Repulse enemy counterattacks in the area extending from the North of Australia Area to the Central Pacific Area. When and if the situation permits, the offensive will be taken and the enemy's war plan disrupted.
The Eighth Area Army commander, in cooperation with the Navy, will hold the important Rabaul area as long as possible in order to facilitate operations in the area extending from the North of Australia Area to the Central Pacific Area.
The Second Area Army commander will continue to carry out his original mission. In addition, with the newly assigned units in eastern New Guinea he will hold the area west of Wewak
and exert every effort to check any enemy advances toward western New Guinea and the western Caroline Islands area.
The operational boundary between the Eighth Area Army and the Second Area Army will be Long, 147°E passing through New Guinea and the Bismarck Archipelago. The Admiralty Islands will be included in the operational zone of the Eighth Area Army.
To supplement these orders, the Army General Staff issued the following three-point directive to the Second Area Army commander:
The Second Area Army commander will withdraw the main force of the 18th Army from the area west of Wewak to strengthen the defense of the air bases at Hollandia, Aitape and Wewak.
The 18th Army will check the enemy advancing toward western New Guinea and the western Carolines. Every effort will be exerted toward destroying the enemy should landings be attempted during the redeployment of the 18th Army.
The Second Area Army will stockpile all available munitions in the area around Hollandia, Aitape and Wewak.
The 18th Army's operation will not in any way interfere with the Second Area Army's operational preparations.
In accordance with previous instructions, the Second Area Army was to hold a line extending from Tanimbar through Aroe to Sarumi in western New Guinea with the area around Geelvink Bay as its center. It was planned to establish an air base near Geelvink Bay. The Army General Staff ordered the Second Area Army to continue to hold this line and the 18th Army, although now attached to the Second Area Army, was to hold the line in front of the Second Area Army's front line.
First and Second Modifications of the Second Area Army's Front Line
On 15 April 1944, the Army General Staff ordered the Second Area Army placed under the command of the Southern Army.
On 22 April, the enemy landed in the vicinity of Hollandia. The Second Area Army still desired to attack beyond its front line but overwhelming enemy air superiority and the fact that no air or ground reinforcements could be hoped for, compelled the Army to carry out a delaying action with its existing forces. It was considered completely impractical to employ the troops and matériel available in an offensive action in the forward area. In order to carry out the Army General Staff's plan, therefore, it was necessary to establish a new defense line to the rear.
On 2 May, orders were issued to the Southern Army commander relieving him of all responsibility for eastern New Guinea and the 18th Army and other units were ordered to withdraw to western New Guinea.
These orders contained three major points which were:
1. The front line to be secured in the western New Guinea area will hereafter be a line connecting the strategic area in inner Geelvink Bay, Manokwari, Sorong and the vicinity of Halmahera. Important positions in the vicinity of Biak will be held as long as possible. Necessary troops will be sent to the island from units in the Sarmi area.
2. Some advanced units of the 35th Division, which were transferred from China in early April to be disposed on St. Andrew Islands, could be sent to such places as the Mapia Islands.
3. The 18th Army and other units in eastern New Guinea will be transferred immediately to western New Guinea.
The Second Area Army commander had planned to send the main strength of the 35th Division (stationed in Sorong) to Manokwari hut enemy air superiority made shipping to Manokwari extremely difficult. The Army General Staff, therefore, ordered the 35th Division to remain at Sorong and defend that sector. This made it necessary to alter again the main line of defense and, on 9 May, orders were issued stating that the front line to be held in the key sectors of western New Guinea was to be a line in the vicinity of Sorong to Halmahera. The important positions of Biak, Manokwari and near Geelvink Bay were to be held as long as possible.
After the enemy landed on Biak during the latter part of May, communications between the Second Area Army and the 18th Army were completely severed. On 20 June, therefore, the Army General Staff placed the 18th Army under the direct command of the Southern Army. Since it was recognized that it was virtually impossible for the 18th Array to withdraw to western New Guinea, in order to give its commander greater freedom of action, Southern Army ordered the 18th Army to hold important regions in eastern New Guinea.
Northeastern Area Directives
In preparation for possible attacks against Hokkaido from the Aleutians, defensive positions on Hokkaido and in the Kuril Islands had been strengthened.
In February 1944, as it was deemed necessary for the Northern Army to be changed from a district army to an operational army, it was redesignated the Fifth Area Army and made responsible to the Chief of the Army General Staff. The operational boundary between the Fifth Area Army and the Eastern Army Command was the Tsugaru Strait. The 27th Army Headquarters was organized for the defense of the Kuril area and, together with the 1st Air Division, was placed under the command of the Fifth Area Army. In mid-March, the Army General Staff published the orders of battle of the Fifth Area Army and the 27th Army. At the same time, the commander of the Fifth Area Army received the following orders:
Plans for the Northeastern Area provide for meeting enemy attacks against the Homeland and for preventing war with Russia.
The Fifth Area Army commander will cooperate with the Navy in expediting operational preparations for the interception of any enemy attacks against the Homeland in the Northeastern Area.
The operational boundary between the Fifth Area Army and the General Defense Command is the Tsugaru Strait. This strait and the Tsugaru Fortress area in Aomori Prefecture (northern Honshu) will be under the command of the Fifth Area Army.
Formosa and the Nansei Islands Directives
In preparation for future enemy attacks from the direction of the Marianas and the Philippines and surprise attacks from other areas, the Army General Staff realized the urgency for speeding up the
reinforcement of the Formosa and Nansei areas. In the latter part of March 1944, therefore, it issued the order of battle of the 32d Army and assigned to this army the mission of protecting the Nansei Islands. The organization of this army was:
32d Army Headquarters
Amami-Oshima Fortress Unit
Nakagusuku Bay Fortress Unit
Funafuchi Fortress Unit
Units under the direct command of the Army
The Army General Staff urged the 32d Army and the Formosa Army to rush operational preparations. This was known as the "10th Operational Preparations."
Orders issued the two armies included the following four points:
1. The Army General Staff plans to strengthen southern Japan.
2. The 32d Army commander will be responsible for the defense of the Nansei Islands. He will cooperate with the Navy in expediting operational preparations.
3. The Formosa Army commander will be responsible for the defense of Formosa. He will cooperate with the Navy in expediting operational preparations.
4. The boundary between the defensive areas of the 32d Army and the General Defense Command will be Lat. 30°10'N. The boundary between the 32d Army and the Formosa Army will be Long. 122°30'E. The boundary between the 14th Army and the Formosa Army will be Lat. 20°10'N.
The objectives of the operational preparations of the Formosa and 32d Armies were to strengthen the defenses of their assigned areas and to maintain transportation between Japan and the Southern Area. They were to be prepared first to repel any enemy surprise attacks and then to meet orthodox enemy landings. Air operational preparations were to be given top priority. Countermeasures against unexpected attacks were to be planned immediately. General operational preparations were to be completed about July 1944.
In connection with air operational preparations, several air bases were to be constructed in the area extending from the east coast of Formosa to the Nansei Islands in order to make air operations easier. Enough air bases were to be developed to enable one air division to be deployed on both eastern Formosa and the Nansei Islands. Sufficient matériel for two air divisions was to be stockpiled in the area before July. After that, efforts were to be made to keep this stockpile at a level sufficient to supply the needs of one air division.
Ground forces were to be developed to protect air bases and main anchorage points. Troops were to be dispatched to the Daito Islands to assist the Navy in building airfields. The Formosa Army was to send a force to defend Batan Island.
Two independent mixed brigades and the 28th Division (from Manchuria), which were being organized in Shanghai, were assigned
to the 32d Army in the early part of May and the latter part of June respectively. The 50th Division and the newly organized 8th Air Division were assigned to the Formosa Army in the early part of May and the early part of June respectively.
In early May, in order to consolidate supply operations, the Army General Staff temporarily transferred the 32d Army from its direct command to the command of the Western Army Command.
Unification of Southern Area Command System
With the continued deterioration of the situation in the Pacific, it became imperative to unify and strengthen the defenses of the Philippines and the North of Australia Area. The Army General Staff, therefore, placed the Second Area Army and the 14th Army under the command of the Southern Army; In addition, on 15 March, the Seventh Area Army was organized at Singapore to more closely coordinate the actions of the forces in the central area of the Southern Army's zone of responsibility. The majority of staff officers from the Southern Army Headquarters, because of their knowledge and experience in the Southern Area, were transferred to the Area Army Headquarters. At the same time, staff officers from Imperial General Headquarters with a knowledge of the over-all picture of the Japanese Army, were transferred to the Southern Army Headquarters. Other reasons given for the unification were:
1. It was certain the Allies would direct attacks against the area extending from the North
of Australia Area to the Philippines. The most important counterattacks would be made by the air force within the defensive sphere. It was necessary, therefore, to unify the command system to obtain the maximum concentration of air strength in the right place and at the right moment.
2. Because the number of ships was limited, it was necessary to transfer matériel within the Southern Area through local transportation. This system could be developed more effectively if placed under one command.
3. In order to enable the Army General Staff to command effectively the over-all operations against enemy attacks from all directions around the defensive sphere, it was necessary to reduce the number of organizations under the direct command of Imperial General Headquarters.
Change of Mission of Southern Army
The Army General Staff's plan was to hold the strategic regions of the Southern Area and the Northern and Central Pacific Areas and to destroy the enemy's fighting power. The plan also called for every effort being exerted to destroy the Chungking Government.
The Southern Army was ordered to cooperate with the Navy in hastening the completion of operational preparations and maintaining security in strategic areas in the south. The advancing enemy was to be annihilated. Defenses were to be strengthened on the Andaman and Nicobar Islands, Malaya, Sumatra, Java and the Dutch East Indies. In cooperation with their governments, Burma, Thailand, French Indo-China and the Philippines were to be secured. An air offensive against India, China, Australia and New Guinea was to be launched at an appropriate time.
The program of self-subsistence in the various areas was to be strengthened to cope with the development of the war situation. Regions containing important natural resources were to be reinforced. Military administration was to be augmented and improved.
In addition, the Southern Army was instructed to cooperate with the Navy, whenever possible, in protecting sea transportation.
The operational boundary between the Southern Army and the Eighth Area Army was to be Long. 147°E passing through New Guinea and the Bismarck Archipelago, with the Admiralty Islands being within the Eighth Area Army's zone of responsibility. The operational boundary between the Southern Army and the Formosa Army was Lat. 20°N. Palau was within the operational zone of the 31st Army, with the St. Andrew Islands within the operational zone of the Southern Army.
Logistically, the Southern Army commander was ordered to give priority to the needs of the Air Force, which were expected to increase sharply. In addition, steps were to be taken to insure unrestricted exchange of matériel between the services in the Southern Area. Local subsistence was to apply wherever possible. The Philippines were designated a supply base for the Southern Area, particularly the North of Australia Area.
Terminal points designated by the Army General Staff were:
Terminal Point Areas Served Manila Philippines Saigon (this point could be moved to Singapore if found necessary for the Burma Operation) Burma, Thailand and French Indo-China Singapore Malaya, Sumatra, Java and Borneo Halmahera and Palau North of Australia Area
If circumstances permitted, supplies for the North of Australia Area were to be sent directly to Manokwari, Sorong or Amboina. Matériel hitherto under the direct control of the Army General Staff in the Philippines was to be placed under the control of the Southern Army. In general, the Army General Staff would not deliver war supplies directly to any of the Southern Army's subordinate commands but rather would deliver supplies to the Southern Army to be distributed at its discretion.
On 15 April, the Southern Army, unable to comply with this order in its entirety, issued orders to its subordinate armies to continue their present missions for the time being.
As part of the reorganization of the command system in the Southern Area, on 15 April, the Seventh Area Army was organized in Singapore and assumed command of the 16th, 25th and 29th Armies and the Borneo Garrison Army. The Second and Seventh Area Armies, the 14th Army and the 4th Air Army were assigned to the Southern Army.
In May, the headquarters of the Southern Army was moved from Singapore to Manila.
In order to conduct air operations within the defensive sphere it was at first considered necessary to organize a unified air force headquarters. After consideration, however, it was feared that this would complicate the command system and the Southern Army assumed command of the air force as it was. The 3d Air Army (5th and 9th Air Divisions) was stationed in Singapore and was responsible for the western front while the 4th Air Army (7th Air Division) was stationed in the Philippines and was responsible for the eastern front. As a decisive campaign was expected in the Philippines in the not too distant future, it was decided to increase the air strength in that area as soon as possible. In mid-May, therefore, the 2d and 4th Air Divisions were transferred to the Philippines from Manchuria.
At this time an unusual split in the organizational structure and responsibilities of the 2d and 4th Air Divisions was ordered. All flying units of the two divisions were placed under the command of the 2d Air Division commander while all service units of both divisions were placed under the command of the 4th Air Division commander. Thus, the 2d Air Division became exclusively a flying division and the 4th Air Division became an air service unit. The purpose of this reorganization was to control and concentrate all air attacks and to expedite air base construction for specific operations. The 2d Air Division was assigned directly to the Southern
Army. The 4th Air Division was placed under the 4th Air Army and assigned the mission of constructing air bases in the Philippines. In late May, the Southern Army also placed the 2d Air Division under the command of the 4th Air Army.
In early April, in order to strengthen the defense capacity of the Southern Area, the 32d Division was placed under the command of the 14th Army commander and the 35th Division, which had been assigned to the 31st Army on arrival from north China, was reassigned to the 2d Army.40
On 11 April, the 33d Army (18th and 56th Divisions) was organized under the command of the Burma Area Army. This Army was activated in order to establish a strong command structure in the important Hukawng River Valley and Yunnan Province area, and relieve the 15th Army of its responsibilities in these areas. The northern flank could be secured and the 15th Army and the Burma Area Army could concentrate on the projected "U-GO" Operation.
In the latter part of April, the 32d Division was reassigned from the 14th Army to the Second Area Army and sent to the Halmahera area. The 30th Division (from Korea) was assigned to the 14th Army and sent to the vicinity of Mindanao.
In order to reinforce the greatly reduced strength of the
forces in Burma, in the latter part of May, the 49th Division (in Japan) was assigned to the Southern Army.
In early June, as an aid to future operational preparations and to ease the burden of responsibility for logistics in the Burma area, the Army General Staff organized the following units:
Southern Army Line of Communications Inspectorate Section
Burma Area Army line of Communications Inspectorate
Section Second Area Army line of Communications Inspectorate Section
These sections were assigned to the respective armies, their mission being to expedite logistic operations.
To reinforce the defense forces in the Philippines, independent mixed brigades and other units, which had been sent to the area, were reorganized. About mid-June, the 100th, 102d, 103d and 105th Divisions and two independent mixed brigades were organized and assigned to the 14th Army.
During May 1944, the Army General Staff had put into motion over-all preparations (No. 11 Operational Preparations) for the possible decisive battle in the Philippines and it was estimated that these preparations should be completed by the end of the summer.
Central Pacific Area Directives
The 14th Division (from Manchuria) had been ordered to move into the North of Australia Area where it was to come under the command of the 2d Army. Enemy operations in mid-March, however, made it imperative to strengthen the defenses of Palau and on 20 March, while
en route, the 14th Division was ordered to change its course and proceed to Palau where it came under the command of the 31st Army.
During the spring of 1944, using all available shipping, the Army and Navy had conducted a prompt and effective redeployment of strength in the Pacific area. Enemy submarines had exacted a heavy toll on shipping but, in spite of this, the over-all defensive position had gradually been improved. The vitally important Marianas and the Ogasawara (Bonin) areas were strengthened; the 29th Division was transferred from Saipan to Guam in early April; the 43d Division was shipped to Saipan from Japan, and the 109th Division was organized from troops already in the Ogasawara Islands.
An outline of the 31st Army's order of battle in late May was:
31st Army Headquarters
Group on Truk
Group Commander: CG, 52d Division
51st Independent Mixed Brigade
52d Independent Mixed Brigade
11th Independent Mixed Regiment
4th South Sea Detachment
Group in the Northern Marianas
Group Commander: CG, 43d Division
47th Independent Mixed Brigade
9th Independent Mixed Regiment
Group in the Southern Marianas
Group Commander: CG, 29th Division
48th Independent Mixed Brigade
10th Independent Mixed Regiment
Group in the Ogasawara Area
Group Commander: CG, 109th Division
12th Independent Mixed Regiment
Group in the Palau Area
Group Commander: CG, 14th Division
49th Independent Mixed Brigade
53d Independent Mixed Brigade
Miscellaneous Groups for other areas
Commander: CG, 31st Army
50th Independent Mixed Brigade for Yap
1st Amphibious Brigade for Marshall and Eniwetok
1st South Sea Detachment for Marshall
2d South Sea Detachment for Ponape and Kwsaie
13th Independent Mixed Regiment for Wake
"A-GO" Operation in the Marianas Area
As early as March 1944, Imperial General Headquarters began to examine ways and means to fight a decisive battle against the enemy steadily advancing from the south toward Japan, By the end of April a plan was drawn up calling for the reorganization of naval forces
and preparations for a naval battle off the Marianas (Philippines Sea Battle). This plan was designated the "A-GO" Operation.
Imperial General Headquarters' estimate of the situation indicated that the enemy was steadily building up strength in the Central Pacific and Southeastern Areas but it was believed that there would be no direct attack against Japan until after the capture of offensive bases in the Philippines. There was some debate as to whether the enemy was planning to advance in the Central Pacific and attack in the area around the Mariana and Caroline Islands at the first available opportunity or whether they would wait until General Mac-Arthur's forces advanced to the North of Australia Area. In either case it was certain that the Japanese Navy would have to join battle with a far superior force.
It was finally decided that the decisive battle would take place in the waters surrounding the Marianas and Carolines and that although it would mean other areas would suffer considerably, the main naval strength should be concentrated in this area. In addition, the Army was instructed to strengthen its defenses and increase its fighting strength on the islands in the anticipated battle area.
The Navy sent the main strength of its naval land-based air units, mostly the 1st Air Fleet (approximately 650 planes) to the Mariana Islands. (Some of these planes were later transferred to the Caroline Islands.) The main strength of the naval surface force, the 1st Mobile Fleet, began to prepare for sorties toward the Mariana Islands from the Sulu Archipelago.
While deciding on the operational plan a discussion had taken place as to what steps would be taken if the enemy attacked Biak before attacking the Mariana Islands. At that time the strength of the land-based air units on the Mariana and Caroline Islands was considered insufficient for the planned decisive battle. It was felt, therefore, that if part of this strength were deployed to Biak Island it would be impossible to undertake the "A-GO" Operation, Under these circumstances, the Navy decided that it would withhold its air strength, even if it meant the loss of the Geelvink Bay area.
Late in May the enemy launched an attack against Biak. The Navy reversed its decision and decided to try and hold the island. This reversal was brought about by the realization of the effect the loss of the island would have on the "A-GO" Operation. The Navy sent approximately one-third of its land-based air strength in the Central Pacific from Palau to the Halmahera area but, shortly after arrival, the majority of the combat personnel in the air units was attacked by malaria. In addition, due to defective air base maintenance and lack of skill of the crews, a great deal of the equipment was damaged. By mid-June, the Allies had occupied the island.
On 15 June, the main force of the enemy fleet attacked Saipan. Though the defenses on Saipan had been constructed hastily and were incomplete they were yet stronger than any used so far in the Southeastern or Central Pacific Areas. The Army General Staff believed that the island could be held and the enemy checked for a long time.
Furious enemy air and naval bombings, however, soon reduced the defenses and Saipan fell after a brief engagement.
At the time Saipan fell, the 31st Army commander was on his way back to his command from a conference on Palau. He was, therefore, compelled to fly to Guam. On Saipan the Chief of Staff of the 31st Army issued orders in the name of the commander but operational preparations had not been completed as it had been estimated that the enemy would not attack before July. In addition, the Army had adopted a policy of defeating the enemy on the beaches and, in consequence, the main positions were constructed close to the shore. In consequence, on the first day these positions were bombarded by enemy naval craft and heavily damaged; heavy casualties resulted and there were no prepared positions to fall back to. Against an overwhelmingly superior air force, the land-based Navy air units were of little help. To aid in the battle, the 1st Mobile Fleet began moving out from the southern Philippines area, arriving in the waters off western Mariana Islands on 19 June. Carrier-based air units attacked the invading enemy but were intercepted by enemy air planes and subjected to intense antiaircraft fire. The battle raged for several days and the Fleet fought desperately believing that this could be the last decisive battle in which the whole strength of the Japanese Navy air and surface forces would be committed. Finally, overwhelmed by U.S. submarines and carrier-borne planes, the Japanese Fleet was forced to withdraw. It had lost the greater part of its land-based
air force and out of the nine aircraft carriers employed, three were lost and four damaged. Of the 360 carrier-borne aircraft employed in this action, only 25 survived. This was a fatal blow to the Japanese Navy.
Meanwhile, the ground units on Saipan, still continuing their stubborn fight, by 28 June had lost their major strength. On 6 July, Vice Admiral Nagumo and Lt. Gen. Saito both committed suicide and, on the morning of the 7th, the remaining troops made a final attack, fighting to the last man. The battle for Saipan ended and the island fell to the enemy. The loss of this island had a tremendous effect on the future conduct of the war. Although some consideration was given to a campaign to recapture the island, Imperial General Headquarters realized that with its badly crippled naval carrier force this was impossible.
The Ogasawara Islands were now regarded as of immense importance strategically. It was practically impossible, however, for the 31st Army to exercise command over this area. Toward the end of June, therefore, the Army General Staff activated the Ogasawara Group (composed mainly of the 109th Division and two infantry regiments located on these islands) and placed it under the direct command of the Army General Staff. It planned to ship troops and munitions to this unit from Japan whenever the transportation situation permitted.
Plans to Strengthen Homeland Defenses
With the Allied forces steadily advancing through the Pacific it was vitally necessary for the Homeland defenses to be strengthened immediately. As a result of studies that had been made continuously since the beginning of the year, in May 1944 the Army General Staff issued the necessary orders to further unify and strengthen the defenses of Japan.
Up to this time the commander of the General Defense Command had not had the power to direct the disposition of troops or the construction of large-scale fortifications but had rather acted as a coordinator between Imperial General Headquarters and the district commands. Now his command authority over the three Homeland armies was strengthened considerably. The Eastern, Central and Western Army Commands and the defensive air forces were placed under the complete command of the commander of the General Defense Command. The 1st Air Army and the Korea Army were also placed under him for defense operations. The Fifth Area Army (Hokkaido) remained under the command of the Chief of the Army General Staff.
Homeland defense duty assignments issued by the Army General Staff were to accomplish adequate reinforcement of Japan. The commander of the General Defense Command was ordered to cooperate with the Navy in carrying out military preparations. The primary objectives were to repel enemy air attacks and protect the strategic regions of the Homeland. Defenses of key points along the coast of
the mainland and outlying islands were to be strengthened. The Army was to cooperate with the Navy in protecting sea transportation. The strongest emphasis was placed upon the development of effective precautionary measures against air raids.
Directives issued to support orders stated that the places most particularly to be protected from air raids were the Imperial Palace and military installations in the Tokyo-Yokohama, Kokura-Yawata, Nagoya and Osaka-Kobe areas. The China Expeditionary Army, Kwantung Army, the Fifth Area Army and the Formosa Army commanders were ordered to cooperate with the commander of the General Defense Command in maintaining lines of communications for intelligence reports on imminent enemy air raids. Various strategic military positions and movements were to be protected against enemy attacks. Every effort was to be exerted to maintain public order. The authority of the commander of the General Defense Command was limited in that he was required to obtain the approval of the Chief of the Army General Staff before changing the location of troops, except in an emergency or for very minor movements.
In the over-all reorganization, the importance of lines of communications within the Homeland was stressed. Supply depots in Japan were unable to maintain the level of supply of matériel required by the overseas armies for many reasons, principal of which were: enemy air raids made it difficult to schedule production; the rapid increase in the number of men required to bolster the Army strength
lessened the number available to industry; and losses at sea and the consequent difficulty in transporting essential natural resources from abroad. It was planned, therefore, to disperse the munitions already stockpiled at supply depots. The execution of this plan was speeded up after the fall of the Marianas. The munitions plants, however, were not moved in order to prevent the lowering of the current production rate inevitable during such a move.
By the end of March 1944, the Army had a mobilized strength of somewhere in the vicinity of 3,650,000 but with the situation daily becoming more critical it was estimated that this would have to be expanded by approximately 1,000,000. As it was recognized that if the situation continued to deteriorate it would be impossible to send troops overseas after the summer, an order was issued requiring this strength to be mobilized prior to June.
Logistical Support During the Third Phase
The supply of operational matériel was inadequate. Enemy air and submarine attacks made shipping extremely hazardous. Every effort was expended in shipping supplies to the strategic areas but, in all other areas, shipping was kept to a minimum. Changing battle situations necessitated changing troop dispositions and it was inevitable that the quality and quantity of munitions and shipping did not always fill the operational needs of the particular situation. Ships were constantly being lost and equipment was fast deteriorating.
All operational armies, under these circumstances, were ordered to establish a system of self subsistence.
Fourth Phase of the War
(July - December 1944)
Summary of Operations During Fourth Phase
On Saipan, by 5 July, the 43d Division had been completely destroyed. On 21 July, the enemy landed and soon occupied Guam. By the 24th, the main base on Tinian had fallen. Garrisons on both these islands had ceased all organized resistance by early August.
On 15 September, Morotai and Peleliu were attacked and, despite desperate resistance, enemy superior strength soon gained control of positions on Peleliu Island and the airfield on Morotai.
In the Burma Theater, the "U-GO" Operation had been unsuccessful and, on 4 July, acting on orders from the Army General Staff, the Southern Army issued orders to terminate this operation. Along the eastern boundary of the Yunnan Province, the units of the 56th Division carried out bold defensive tactics, inflicting heavy casualties on a superior enemy. Finally, however, the Myitkyina and Lameng Garrisons were overwhelmed and, between 4 and 7 August, were destroyed. The situation in north Burma was regarded as hopeless.
In China, the Hunan-Kwangsi Operation (ICHI-GO) continued to progress smoothly. On 8 August, Hengyang was captured then, after a month of consolidation, the attack was resumed. On 10 November,
Kweilin and Liuchow were occupied. The 11th Army continued to pursue the enemy and, by 2 December, had reached and occupied Tuhshan. Earlier, in order to prevent the United States Army from landing and occupying coastal bases as well as to secure surface transportation and establish bases for naval combat in China, the Army General Staff had directed the China Expeditionary Army to capture and hold the main coastal areas in eastern Chekiang Province. On 9 September, Yungchia was captured and, by early October, Fuchou was occupied.
During this period raids against Japan by large enemy bombers increased. Kyushu was raided on 8 July and Dairen, Anshan and Mukden on the 29th. From August onward, enemy B-29's continuously attacked Kyushu, Manchuria and Korea. On 24 November, apparently using Saipan as an airbase, the enemy raided Tokyo.
A strong enemy task force attacked Okinawa on 10 October and Formosa on the 12th, 13th and 14th. The main strength of the Japanese Navy Air Force with an element of the Army Air Force attached, counterattacked and inflicted heavy casualties on the enemy off Formosa.
On 19 October, the enemy landed on Leyte. At first the Fourteenth Area Army was reluctant to conduct a decisive battle for Leyte on the grounds that the forces and materials required would be a drain on Luzon and, should the battle for Leyte fail, Luzon could not be held. Later, on the basis of a report that the Navy
Air Force bad dealt a severe blow to the enemy carrier force east of Formosa, in mid-October, Imperial General Headquarters insisted that a strong stand be made on Leyte.41 The Southern Army, assuming that the planned reinforcement of Luzon could be accomplished, concurred and the Fourteenth Area Army and the 4th Air Army threw their entire strength into the battle for Leyte.
The Combined Fleet, in an effort to destroy the United States Fleet approaching Leyte from the east, fought major sea engagements. Both the Army and Navy suffered such heavy losses that, by mid-December, it was necessary to abandon any major operation on Leyte. On 15 December, the enemy began landing on Mindoro.
The failure of "SHO-GO" Operation, No. 1 (Decisive Battle for the Philippines) narrowed the Japanese sphere of influence to Japan Proper, the area north of Formosa and China.
On 9 November, Stalin publicly stated that Japan was an aggressor nation.
Preparations for and Development of "SHO-GO" Operations
With the loss of the Marianas area and the heavy losses suffered by the Japanese Navy during the Battle of the Philippines, the strategic position was completely changed. Not only did these losses place the enemy in a favorable position in the attack on the Philippines but, in addition, they could now bomb Japan from bases in the
Marianas. In the past, the enemy had selected landing points within range of his land-based aircraft. In the Mariana Operation, however, the enemy had effected a large-scale operation by coordinating the actions of the Army, Navy and a strong task force far beyond the range of land-based aircraft.
As the situation became increasingly worse, the weakness of Japan's defenses became more clearly evident.
The "U-GO" Operation had failed and a counterattack seemed hopeless. The Japanese Army in north Burma repeatedly withdrew under pressure from a superior enemy and regrouping of forces became daily more difficult.
Furious enemy attacks from the east and west, together with intensified attacks on sea transportation, not only separated Japan Proper from the Southern Area but also gradually isolated the islands in the Southern Area. This rapid breakdown of the strategic situation, allied with an acute shortage of matériel caused by the cutting of lines of communications, delay in personnel and matériel reinforcements, deterioration of Japan's political influence upon nations in the Co-Prosperity Sphere and growing unrest within Japan itself brought about the most serious crisis since the outbreak of the war. Finally, it resulted in the retirement of the Tojo Cabinet and the formation of the Koiso Cabinet in July 1944.
After careful investigation and consideration of all aspects of
the situation, Imperial General Headquarters proceeded with the preparations for subsequent operations. The defense of the sea front connecting the Philippines, Formosa, Hansei Islands, the Japanese Homeland and the Kuril Islands was to be strengthened* Preparations were to be made to intercept and destroy the enemy by concentrating the Army, Navy and Air Forces wherever the enemy attempted attacks against this line. This was to be known as the "SHO-GO" Operations.
The Hunan-Kwangsi Operation was to be completed as planned. The problem of sea transportation was to be reduced by supplementing continental land transportation, while, at the same time, every effort was to be exerted to secure coastal transportation.
During the latter part of July, the Commander in Chief of the Southern Army, the Commander in Chief of the China Expeditionary Army, the Commander in Chief of the General Defense Command and the commanders of the Formosa and Fifth Area Armies received Army Department Order No. 1081 dated 24 July 1944, which stated that Imperial General Headquarters planned to direct a decisive battle against the
main body of the United States forces during the latter part of the year.42 It was estimated that the decisive battle would be fought in the Philippines, Japan Proper or in the area between. Imperial General Headquarters would later determine the exact time and place of this operation. The armies concerned, in cooperation with the Navy, were to make immediate preparations for a decisive battle.
Directives were issued supplementing this order and the Army commanders were ordered to complete basic preparations according to the schedule listed below:
SHO-GO, No. 1 Decisive Operation in the Philippines Area - end of August SHO-GO, No. 2 Decisive Operation in Area between Japan Proper and the Philippines - end of August SHO-GO, No. 3 Decisive Operation in Japan Proper (excluding Hokkaido) - end of October SHO-GO, No. 4 Decisive Operation in the Northeastern Area (Kuril Islands, Sakhalin and Hokkaido) - end of October
Army commanders also received directives instructing them to plan and prepare for the deployment of their troops in the following manner:
The Commander in Chief of the Southern Army will prepare and have a unit (with one brigade as a nucleus) in the northern Philippines ready for transfer to Formosa or the Nansei Islands.
The Formosa Army commander will prepare and have on Formosa a unit (with one brigade as a nucleus) ready for transfer to the Philippines or the Nansei Islands.
The Commander in Chief of the General Defense Command will prepare and have a detachment in the vicinity of Kagoshima (three infantry battalions and one artillery battalion as a nucleus) ready for transfer to the Nansei Islands area. He will also prepare and have in the vicinity of Himeji another detachment (same strength) ready for transfer to the Ogasawara Islands.
In the event "SHO-GO" Operations. Nos. 1 and 2 take place, Imperial General Headquarters will prepare and have in the vicinity of Shanghai a unit (strength about one division) ready for transfer to the Philippines, Nansei Islands or the Formosa area.
In the event "SHO-GO" Operations, Nos. 3 and 4 take place, Imperial General Headquarters will prepare and have the 47th Division in the vicinity of Hirosaki ready for transfer to the northeastern part of Honshu or Hokkaido.
In the event "SHO-GO" Operation, No. 3 becomes necessary, the 36th Army is scheduled to be placed under the delegated command of the Commander in Chief of the General Defense Command.43
As the "SHO-GO" Operations concept demanded a unified operation by the Army and Navy Air Forces, a Central Agreement on air operations was concluded between the Army and Navy General Staff on 24 July. This stated that Army and Navy Air Force preparations for the decisive battle would be completed by the end of August. In the event of an enemy invasion, the entire air strength would be concentrated in the decisive battle area and would crush the invading strength through unified operations.
The basic disposition of the Army and Navy air strength was to be as shown below and, in the case of a decisive battle in each sector, it was to be employed as shown in Chart No. 12.
12th Air Fleet
1st Air Division
Japan Proper (excluding Hokkaido):
3d Air Fleet
Air Units of the 3d Fleet (whenever in the Japan Proper area)
Air Training Army
10th Air Division
11th Air Division
12th Air Division
Nansei Islands and the Formosa Area:
2d Air fleet
8th Air Division
Philippines, North of Australia and Central Pacific Area:
1st Air Fleet
4th Air Army
Disposition will remain as at present.
The operational policy for air units prior to the actual start of the "SHO-GO" actions called for the air strength to be disposed in depth. Operational guidance was to be as flexible as possible. Efforts were to be made to decrease the enemy's fighting effectiveness, particularly by short and effective surprise attacks with stress being laid on opportune interception of enemy aircraft. As a general rule, direct defense of the bases was to depend on antiaircraft fire.
Chart No. 12a
SHO-GO Operations Air Strength
Army Air Strength Employment Outline
Area Unit Strength Strength to be Employed SHO-GO, No. 1 SHO-GO, No. 2 SHO-GO, No. 3 SHO-GO, No. 4 Northeastern Area 1st Air Division 1 Fighter Regt Strategic Reserve Strategic Reserve Strategic Reserve Total Strength 2Hv Bmr Regts 1 Lt Bmr Regt 1 Recon Regt Japan Proper 10th Air Division 7 Fighter Regts Total Strength 1 Recon Regt 11th Air Division 4 Fighter Regts Total Strength 12th Air Division 2 Fighter Regts Total Strength 1 Recon Regt Air Training Army 8 Fighter Regts 2 Fighter Regts Main Force Total Strength 2 Fighter Regts 2 Hv Bmr Regts 1 Lt Bmr Regt 1Lt Bmr Regt 1 Hv Bar Regt 1 Hv Bmr Regt 2Recon Regts 1 Hq Recon Regt Formosa 8th Air Division 4 Fighter Regts 1 Fighter Regt Total Strength 1 Hv Bmr Regt Strategic Reserve 1 Hv Bmr Regt 1 Lt Bmr Regt 1 Lt Bar Regt 1 Hv Bar Regt Philippines 4th Air Army 5 Fighter Regts Total Strength 2 Fighter Regts 2 Fighter Regts Strategic Reserve 2 Hv Bmr Regts 1 Aslt Regt 2 Lt Bar Regts 1 Hv Bmr Regt 2 Aslt Regts 2 Aslt Regts 1 Hq Recon Regt 2 Hv Bmr Regts 1 Recon Regt 5th Air Army 5 Fighter Regts 2 Fighter Regts 2 Fighter Regts 2 Fighter Regts Strategic Reserve 2 Lt Bmr Regts 2 Lt Bmr Regts 2 Recon Regts
Chart No. 12b
SHO-GO Operations Air Strength
Navy Air Strength Employment Outline
Area Unit Strength Strength to be Employed SHO-GO, No. 1 SHO-GO, No. 2 SHO-GO, No. 3 SHO-GO, No. 4 Philippines First Air Fleet 4 Attack Units Entire Strength Major Strength Strategic Reserve Strategic Reserve 5 Fighter Units 1 Recon Units Formosa and Nansei Islands Second Air Fleet 4 Attack Units Major Strength Entire Strength Major Strength Element 7 Fighter Units 2 Recon Units Homeland Third Air Fleet 3 Attack Units Strategic Reserve Major Strength Entire Strength Major Strength 5 Fighter Units 1 Recon Units Hokkaido Twelfth Air Fleet 4 Attack Units Strategic Reserve Strategic Reserve Major Strength Entire Strength 2 Fighter Units Homeland Third fleet 2Mixed Units (carrier planes) 2 Mixed Units (carrier planes) 2 Mixed Units (carrier planes) 2 Mixed Units (carrier planes) 2 Mixed Units
3Attack Units 4Fighter Units 1 Recon Units Southwest Area Thirteenth Air Fleet 2 Attack Units 2 Attack Units Strategic Reserve Strategic Reserve 1 Fighter Unit 1 Fighter Unit China China Area Fleet 2 Mixed Units 2 Mixed Units Strategic Reserve Strategic Reserve
If an enemy task, force were found to be advancing by sea, an element of the Air Force was to launch a surprise attack and inflict all possible damage on its aircraft carriers. The carriers were to be allowed to come within the shortest possible range when the entire strength of the Army and levy Air Forces was to attack incessantly day and night to destroy both carriers and transports.
Air defense was to be strengthened against enemy surprise air attacks on strategic areas in the Homeland. Should these occur, irrespective of previous orders, the initiative was to be taken in attacking enemy carriers and planes.
As part of the preparations for the "SHO-GO" Operations, the following adjustments in the distribution of strength were made:
SHO-GO, No. 1 Area: (Philippines)
On 28 July, the 14th Army was reorganised as the Fourteenth Area Army. The 35th Army was activated and was placed under the command of the Fourteenth Area Army. The 35th Army commander was ordered to assume control of all units in central and southern Philippines.
The 26th Division from Mongolia was assembled for transfer at Shanghai and the 8th Division and 2d Tank Division from Manchuria were assembled at Pusan and Poli respectively. All three divisions were placed under the command of the Fourteenth Area Army in early August.
The order of battle for the Fourteenth Area Army was:
Fourteenth Area Army Headquarters
35th Army (composed mainly of the 16th, 30th, 100th and 102d Divisions, 54th Independent Mixed Brigade and supporting units)
2d Tank Division
55th, 58th and 61st Independent Mixed Brigades
SHO-GO, No. 2 Area (Formosa and Nansei Islands)
In late July the 32d Army (Okinawa) was removed from the command of the Western Army Command and placed under the command of the Formosa Army. Also in July, the 62d Division (China) and the 24th Division (Manchuria) were placed in the order of battle of the 32d Army while the 66th Division (China) and the 10th Division (Manchuria) were placed under the command of the Formosa Army.
SHO-GO, No. 3 Area (Homeland)
In late July, the 36th Army (composed mainly of the 81st end 93d Divisions and 4th Tank Division) was activated and its main force concentrated in the Kanto District and at the foot of Mt. Fuji.
In early July, the 47th Division (Hirosaki) was placed under the direct command of Imperial General Headquarters. The strength on the Ogasawara and Izu Islands was increased and the Homeland defense front was strengthened by putting into force wartime defense measures in each Army District in the Homeland.
In mid-July the 11th Air Division (Osaka) and the 12th Air Division (Ozuki) were activated with the 18th and 19th Air Brigades as a nucleus. These two air divisions, together with the already established 10th Air Division comprised the main air defense force in the Homeland.
In June, all air training schools had been reorganized into air training divisions. Simultaneously, the Air Training Army Headquarters was established to order and instruct air operations in Japan. As this headquarters had been organized from the staff of the Inspectorate General for Army Aviation, personnel served in dual capacities on both staffs.
These transfers represented the completion of troop adjustments for the "SHO-GO" areas.
After the fall of Saipan, commanders began to doubt the efficiency and effectiveness of the present method of island defense - the construction of first-line defense positions in order to destroy the enemy before he could establish a beachhead. After considerable study, Imperial General Headquarters published a plan to revise and unify the tactics of the entire army in regard to island defense. It first issued a pamphlet "The Main Points for Island Defense" for temporary use. Later, "The Instructions Manual for Island Defense" was compiled and published to familiarise the Army with new coastal defense tactics. This called for the construction of beach positions in front of the main line of defense. The first positions were to
be used to inflict as heavy casualties as possible on the enemy during landings, with particular stress on automatic weapons fire. The main line of defense was to be established in depth and width behind the beach positions at key points. Additionally, a last line of entrenchments was to be prepared from which delaying actions were to be undertaken should the enemy overrun the main line of defense. Finally, following the full use of all positions and fire power to inflict casualties on the enemy, a counterattack was to be launched to destroy the enemy.
Since the use of automatic weapons in beach combat was highly regarded, after August many independent automatic weapons units were organised and attached to various units in the "SHO-GO" areas as part of the preparations for the "SHO-GO" Operations.
Preliminary Actions Leading to "SHO-GO" Operation, No. 1
The enemy invasion of Morotai and Peleliu on 15 September was Judged to be a preparatory operation for an attack on the Philippines. It was estimated that soon after the occupation of these two islands the enemy would launch its attack against the Philippines as, both strategically and politically, the occupation of this area would be of great value to the Allies. Imperial General Headquarters estimated that although the enemy would continue to intensify air raids against the heart of Japan and might plan to capture the Ogasawara Islands, there was little probability of a landing operation against
the vital areas of the Homeland during 1944. Lack of bases and the difficulty of maintaining supply lines, as well as friendly and enemy strategic dispositions, would prevent this.
Weather conditions and high seas in the Northeastern Area would prevent enemy attacks in that area before the spring of 1945. Enemy attacks on Formosa and the Hansei Islands were Judged unlikely for the same reasons as attacks against Japan Proper.
No major enemy activities were expected in the North of Australia Area. However, a diversionary operation could be expected by the Dutch-Australian forces as support for the main enemy offensive against the Philippines.
In coordination with the offensive to be launched by the American Army in the Pacific, the British Army was expected to take the offensive after the monsoon season in Burma and the Indian Ocean area. It was believed, however, that the British would not conduct a large-scale operation if the American Army on the Eastern Front were destroyed.
Imperial General Headquarters at first held the opinion that an operation should be conducted to recapture Peleliu and Morotai in order to assist the operational preparations and movements in the Philippines. Further study, however, convinced them that the resultant loss of air and naval strength would not Justify such action. It was decided, therefore, to use only an element of the Air Force to harass enemy movements.
On 21 and 22 September, Luzon was subjected to intense enemy air attacks and Manila and the air bases in the vicinity suffered heavy losses. The attack on the 21st was a complete surprise owing to the ineffectiveness of air intelligence with its shortage of air search radar.
In the light of this estimate of the enemy situation and their intensified activity in the Philippines, Imperial General Headquarters estimated that the time was fast approaching when it would be necessary to put into operation the "SHO-GO"Operations Plan which called for a decisive battle in the Philippines. On 22 September, therefore, Imperial General Headquarters issued the following order:
Imperial General Headquarters estimates that the decisive battle area will be the Philippines and that the time will be some time after late October.
The Commander in Chief of the Southern Army, the Commander in Chief of the China Expeditionary Force and the Commander of the Formosa Force will complete operational preparations to accomplish their respective missions with the target date set as late October.
When the "SHO-GO"Operations Plan had been published in July, there was strong evidence that the enemy's main counteroffensive would be directed against the Philippines area but the situation necessitated taking the strictest defense measures in other areas. Imperial General Headquarters, therefore, directed commanders to prepare for the decisive battle in the Philippines but, in addition, to prepare for emergencies in the other areas.
Prior to this, the Army General Staff had made an intensive study of tactics to he used by the Army Air Force during the decisive battle and had decided that enemy convoys would be the main attack target of the Army Air Force. The Southern Army recommended that enemy aircraft carriers be the priority target but this was not accepted as the Army General Staff held the view that not only should the carriers be attacked but that the convoys also should be destroyed. It was planned to allow the enemy to approach and then, when it was too late to break away, the concentrated Army and Navy air strength was to strike. It was necessary to time the launching of the "SHO-GO" Operation very precisely. If it were premature, the Japanese inferior air strength would be destroyed prior to the decisive battle and, if too late, the enemy would accomplish its mission.
In mid-September, the Southern Army commander sent his Operations Staff Officer to Tokyo to emphasise his recommendations in regard to starting "SHO-GO" Operation, No. 1. The Southern Army commander was convinced that the United States forces would land in the Philippines very soon and felt that the concentration of ground, air and sea forces should be started immediately to avoid delays in meeting the demands of a last minute decision to repel an enemy landing force in the Philippines. By beginning to concentrate the forces immediately he felt that the transfer of strength could be accomplished more easily and surely as it would be under
way before the full enemy sea and air power was operating in the area. The Army General Staff replied that orders for "SHO-GO" Operation, No. 1 would be published following a thorough investigation then being carried out. The Army General Staff was waiting for the right moment and considered that the time suggested by the Southern Army commander was too early.
On 22 September, the 1st Division was transferred to the Fourteenth Area Army and sent to the Philippines area. In addition, many sea raiding units were attached to the Fourteenth Area Army, the Formosa Army and the 32d Army. The 23d Division was ordered to assemble in southern Manchuria under the direct command of the Kwantung Army commander.
Conduct of "SHO-GO" Operation, No. 1
From the beginning of October enemy planes daily attacked and destroyed Japanese planes in the Philippines. It was estimated that between 500 and 1,000 planes came over each day. Further, enemy surface craft were advancing swiftly toward Leyte. To bolster air strength in the Philippines, the 30th Fighter Group was formed from picked strength of the fighter units in Japan and dispatched to the Philippines where it was placed under the command of the 4th Air Army. Also in October, the Manila Defense Command was established in Manila.
On the evening of 18 October, having that day made a full report to the Throne, Imperial General Headquarters, Army Section,
ordered "SHO-GO" Operation, No. 1 to be put into action without delay The substance of this order was:
The decisive battle of the Japanese forces will take place in the Philippines area.
The Commander in Chief of the Southern Army, in cooperation with the Navy, will direct the decisive battle against the main body of the United States forces attacking the Philippines.
The Commander in Chief of the China Expeditionary Army and the Tenth Area Army commander will exert every possible effort to assist and support the forces conducting the decisive battle.44
According to the prearranged plan, air strength began to concentrate in the Philippines area.
On 20 October the enemy landed approximately three divisions on Leyte. Following a fierce air battle, land actions were steadily e
xpended and intensified. Delay in receiving information, loss of an opportunity to concentrate its battle strength and bad weather had all combined to prevent the Air Force from destroying the enemy convoy at sea.
Prior to this, when the original "SHO-GO Operational Plan" had been draw up in July, it had called for all-out decisive air, sea and ground battles to be fought should the enemy attack Luzon but, should the enemy attack the central and southern Philippines, while
decisive air and air battles were to be fought, a decisive ground battle was not to be undertaken. The reason for this policy was that it was recognized that the strength of the Fourteenth Area Army was not sufficient to cover the entire Philippines area in decisive operations. Later, on the basis of a report that the Navy Air Force had dealt a severe blow to the enemy carrier force east of Formosa, Imperial General Headquarters insisted that a strong stand be made on Leyte. Additional impetus was given to the latter plan by the apparent success of the Army Air Force during the early stages of the enemy landings on Leyte. Under these circumstances, the Fourteenth Area Army and the 4th Air Army threw their entire strength into the battle for Leyte. Exception taken by some officers of the Fourteenth Area Army to the revised plan was quickly settled by command authority and, although there were a number of differences of opinion in regard to tactics, these too were resolved through the chain of command.
Reinforcements, in accordance with the "SHO-GO" plan, were quickly dispatched from the various areas and fierce battles were fought both on land and in the air.
About the same time, the Navy General Staff planned to use the main force of the Combined Fleet in an offensive toward Leyte. The Army felt there was little chance of success in such a maneuver but the Navy persisted, and the Combined Fleet moved from Singapore to
the sea east of the Philippines to carry out its plan. Although it inflicted heavy casualties on the enemy fleet in the sea battle on 25 October, the Japanese Fleet suffered far greater casualties and was forced to retreat. This critical loss of Navy strength seriously lowered the chances of success not only in the Leyte Operation but also in the over-all operational situation. Enemy task forces now dominated the sea surrounding Japan Proper and in the East and South China Seas.
On 2d October, a restatement of tactical principles in the form of an Army and Navy Agreement for air operations to defeat the enemy landings was concluded at Imperial General Headquarters. This strengthened the High Command's tactical unity through the chain of command. An outline of the agreement provided:
The Army and Navy will commit the greater part of their respective air units, replacements and aircraft to the Philippines area for use in the "SHO-GO" Operation, No. 1.
The principal missions of the Army and Navy Air Forces are as follows:
Navy Air Force - interdiction operations against enemy surface craft carrying supplies or reinforcements to the landing forces, (this will include destruction of enemy transports in the vicinity of the anchorage) and the destruction of enemy task forces.
Army Air Force - neutralization of enemy air bases, seizure of air control over enemy anchorages and vicinity and the destruction of enemy transports (including during debarkation from transports), plus direct support of ground operations.
Units of the Special Attack Units shall be employed in line with their basic missions.
Army and Navy commanders shall make special efforts to perform these duties by securing air supremacy in operational areas. According to the situation they will take advantage of every opportunity to cooperate in accomplishing the objectives of "SHO-GO" Operation, No. 1.
During the early stages of the operation, the 4th Air Army, with its entire strength using suicide tactics, repeatedly attacked and inflicted heavy losses on enemy convoys. The expected reinforcements from Japan did not arrive, however, and gradually the 4th Air Army lost its strength.
On 1 November, a second order calling for air reinforcements for "SHO-GO" Operation, No. 1 was issued. Strenuous efforts were made by both the Army and Navy to transport replacements of both planes and personnel but with little success. Not only was it practically impossible to reinforce the air units but, due to the intense activity of enemy planes and torpedo boats, it was equally difficult to send
ground forces to Leyte. In an effort to strengthen the area during November the Army General Staff transferred the 10th and 23d Divisions from the Tenth Area Army and the 19th Division from the Korea Army to the Fourteenth Area Army.45 Further, it ordered the Kwantung
Army commander to hold the 12th Division ready for shipment to the Philippines. In early November the 2d Airborne Raiding Brigade was placed temporarily under the Southern Army commander, and, on the 28th, the 1st Airborne Raiding Group was placed under the command of the 4th Air Army commander. At the time these units were dispatched to the Philippines, the 2d Airborne Raiding Brigade was made an organic unit of the 1st Airborne Raiding Group.
By 14 December the Fourteenth Area Army had decided that no good purpose could be served by prolonging the Leyte Operation and began to withdraw from the island. It did, however, order the 35th Army to remain end to continue to resist alone.
The United States forces accelerated construction and repair of bases on Leyte in preparation for an attack against Luzon. On 15 December, they landed on Mindoro.
The most critical element in the preparations for "SHO-GO" Operation, No. 1 was sea transportation. From August, overwhelmingly superior enemy air and sea strength had inflicted tremendous losses on the Japanese Navy and made the strengthening of the Philippines an almost impossible task. Further, enemy air attacks bad cut local transportation within the Philippines so that operational preparations, of even the smallest advance units, always presented problems. In an effort to guard essential war matériel aboard transports it was divided and loaded on several transports in the hope that at least part of the convoy would get through. Emphasis was placed on
speed in unloading transports in order to avoid air attacks at the port.
In spite of all precautions, the Leyte Operation opened with only 50 to 60 per cent of the planned operational preparations completed.
Operations in Other Areas
In the Central Pacific Area during the second half of July the enemy had landed on Guam and Tinian. After July no word was received from the garrison on Guam and, after early August, all communications with Tinian had ceased.
It was believed that the enemy had started large-scale construction of air bases in the Marianas as air raids on the Ogasawara Islands greatly increased. These raids made it difficult to complete the planned reinforcement of the Ogasawaras.
In May 1944, the Southern Army Headquarters had moved to the Philippines to coordinate the operations of the Fourteenth Area Army, the 4th Air Army and the Navy. From this distance, however, it was found difficult to direct operations in such areas as Burma where the situation was critical. In early August, therefore, the Southern Army commander requested permission from Imperial General Headquarters to move his headquarters back to Singapore or Saigon but it was not until mid-November that permission was granted to move to Saigon.
The 15th Army fought valiantly in the Imphal sector but an overwhelmingly superior enemy, allied with serious supply and replacement
problems, forced the Army to suspend the operation in July 1944. At this time it began withdrawing its troops toward the Irrawaddy River in order to regroup and establish strong defensive positions.
In mid-September, the Army General Staff ordered the Southern Army to secure strategic areas in southern Burma to form a strong north flank for the Southern Area, and simultaneously to cut communications between India and China. The Southern Army, in turn, assigned this mission to the Burma Area Army.
Although the 15th Army finally succeeded in assembling its forces on the left bank of the Irrawaddy River, continuous fighting over a long period of time had greatly decreased its effective strength making it evident that, without reinforcements, it could only delay the enemy's advance.
In northern Burma, the 33d Army fought strongly against a superior enemy force in an endeavor to cut communications between India and China. At the end of the year, however, an ever-increasing enemy force continued to prevent them from achieving their objective.
On the southwest coast, the 28th Army held its own, with no important changes being reported.
During this period, the 5th Air Division of the 3d Air Army closely cooperated with and greatly assisted the Burma Area Army's operations.
Previously, defense of the Celebes, Borneo, Andaman and Nicobar had been the responsibility of the Navy. In late September, Imperial General Headquarters revised the Central Agreement in regard to the defense of strategic areas in the south. At this time it was decided that the Navy would continue to be responsible for all sea operations but that all other operations would be the joint responsibility of the Army and Navy, with both Army and Navy units being stationed in the necessary areas. In late October the Agreement was again revised making the Army entirely responsible for defensive land operations in the Southern Area. The Second Area Army commander in the Celebes, the 37th Army commander (until 22 September known as the Borneo Garrison Army commander) in southern Borneo, and the 29th Army commander responsible for both Andaman and Nicobar Islands, were ordered to take command of the Navy land units in their respective sectors, in addition to their Army units.
Earlier, in July and August, when an enemy attack on the Philippines and the North of Australia Area seemed imminent, the Army General Staff had studied a command system for the Philippines, North of Australia, Borneo and the Java areas. Three alternatives were considered:
1. The present command system system would be maintained. The Fourteenth Area Army end the Second Area Army would be responsible for the Philippines and the North of Australia area respectively. The Seventh Area Army would be responsible for Borneo and Java.
2. The Philippines and north Borneo would be placed under the command of the Fourteenth Area Army while the north of Australia Area, Celebes end Java would be the responsibility of the Second Area Army.
3. The Borneo Garrison Army would be transferred from the Seventh Area Army to the direct command of the Southern Army.
After due consideration, it was decided that under normal conditions, from a strategic standpoint for defensive operations in the Philippines, since the Philippines and Borneo were closely related and separated only by the Sulu Sea, the second proposal was the best. Furthermore, it would be to the Second Area Army's advantage to have a well secured deep operations zone behind its responsible sector. Since the situation was becoming increasingly critical, however, it was felt that any large scale change in responsible sectors should be avoided. The third proposal, therefore, was adopted and, in September, the necessary orders were issued. Actually, this proved advantageous as the Southern Army commander could now easily control the strategic relationship between the Philippines and Borneo.
In October, the 94th Division was activated and placed under the command of the 29th Army commander. During the same month, a Singapore Defense Command was established and placed under the command of the Seventh Area Army commander.
In November, in order to bolster strength in Burma, the Southern Army transferred the 49th and 53d Divisions to the command of the Burma Area Army.
In French Indo-China, Thailand and Malaya there were only token garrison forces. In order to reinforce these areas, therefore, the Southern Army requested about five new divisions. The Army General Staff, having studied the general disposition of all Army strength, in December transferred the 37th Division from the 11th Army in China to the French Indo-China Garrison Army and planned to transfer the 22d Division (also in China) to the Southern Army in the near future.
In October, an enemy task force had appeared off Formosa and had raided not only Formosa and the adjoining area but also Okinawa. Believing that the Navy had already destroyed the main strength of the task force and in order to avoid depleting its already weak air strength, the Japanese refrained from counterattacking. Army ground units exerted every effort to maintain the efficiency of the air bases through constant repair and antiaircraft defense activities. Finally, Navy air units were sent from Japan to Okinawa and made a surprise attack on the enemy task force off Formosa but with little result.
Since the activation of the Fifth Area Army and the 27th Army in March 1944, they had been reinforced gradually by successive mobilization. By July, the 7th and 77th Divisions had been completed as tactical divisions and, together with the 7th Depot Division, were placed under the command of the Fifth Area Army commander. In August, the 69th Independent Mixed Brigade was assigned to the 27th Army.
In China, as mentioned previously, in the latter part of May the 11th Army began its Hunan-Kwangsi Operation, which was the second phase of the "ICHI-GO" Operation. This operation progressed smoothly. Changsha was captured in mid-June, Hengyang in early August and Lingling in early September. In late July, the 23d Army (two divisions and two brigades) started its operation, moving north from Canton. This too proved successful. On 10 November, Kweilin and Liuchow were captured and, by late January 1945, the Canton-Hankou Railway Penetrating Operation was completed. Thus "ICHI-GO" Operation came to a successful conclusion.
In addition, an element of the 13th Army, in cooperation with the Navy, captured Yungchia in early September and Fuchou in October. This was done in order to prevent interruption of lines of communications and to control the strategic areas along the coast of China.
The Wuchang-Hankou Defense Army had been organised temporarily by the China Expeditionary Army to guard the Wuchang-Hankou area. In mid-July Imperial General Headquarters redesignated this army the 34th Army with the same organisation, disposition and mission as the Wuchang-Hankou Defense Army.
Also in July, the following divisions were organized and placed in the orders of battle of the following armies:
114th Division - 1st Army 115th and 117th Divisions - 12th Army 118th Division - Mongolia Garrison Army
After the conclusion of the Hunan-Kwangsi Operation, Imperial General Headquarters considered it necessary to establish an area army to facilitate the general command and control of the 11th, 23d and 34th Armies, as well as the army groups in the area between the 11th and 34th Armies' areas of responsibility. In late August, therefore, it ordered the organisation of the Sixth Area Army and placed it under the command of the China Expeditionary Army. Organization of the Sixth Area Army was completed on 10 September as follows:
Sixth Area Army Headquarters (27th, 64th and 68th Divisions)
11th Army (3d, 13th, 34th, 40th, 38th and 116th Divisions)
23d Army (22d and 104th Divisions)
34th Army (39th Division and 5th Independent Mixed Brigade)
In addition, en army headquarters was required in order to place the various units disposed from Changsha to Hengyang under a single command, to facilitate the advance of the 11th Army and preparations for its subsequent operations. In late September, therefore, Imperial General Headquarters issued orders transferring the 20th Army Headquarters from Manchuria and, in mid-October, this headquarters arrived in the Wuchang-Hankou sector. Imperial General Headquarters then ordered the 27th, 64th, 68th and 116th Divisions, together with other units to the rear of the 11th Army, organized into the 20th Army and placed this army under the command of the Sixth Area Army.
In October, the 47th Division was transferred from Japan and placed under the command of the Sixth Area Army.
In November, the Governor General of Hong Kong was placed under the command of the Sixth Area Army.
As mentioned previously, in Manchuria and Korea, from August to December 1944, the 20th Army Headquarters, 1st, 8th, 10th, 12th, 19th and 23d Divisions, 2d Tank Division and the 68th Brigade were withdrawn from Manchuria and Korea. Most of these organizations were transferred to the Philippines with some elements being transferred to Formosa and China. During the same period, the 108th, 111th, 112th, 119th end 120th Divisions were organised in Manchuria and Korea.
Since 1943 most of the reserve matériel accumulated in Manchuria had been sent to the Southern Area. Later, additional military equipment, which had been issued to the Army units in Manchuria, was also transferred to the Southern Area.
On many occasions the Army General Staff warned the Kwantung Army commander to prevent any provocation which might lead to war between Japan and the Soviet Union as, with the Kwantung Army's greatly reduced strength, a defensive action against the Soviet Army might prove very difficult.
Army units in Japan were constructing coastal defense positions, especially in southern Kyushu, southern Shikoku, Ise, Toyohashi, Sagami, Chiba-Ibaragi, Sendai and the Aomori areas. By December, the
basic construction in most areas was completed and, from then on, this was gradually strengthened.
From November 1944, enemy air attacks on Tokyo, Nagoya, Osaka and northern Kyushu increased in intensity. Not only did they destroy great sections of the cities but they seriously impeded important war production. The Army General Staff, therefore, took special steps to strengthen air defenses, including replenishing and fully equipping air defense units.
As part of this program, in late December the Air Training Army Headquarters was dissolved and the 6th Air Army Headquarters was established under the commander of the General Defense Command. This headquarters was responsible for the preparation of air operations for the final defense of Japan.
One of the greatest problems at this time was supply. Investigations were held and preparations made to gradually accomplish the following five-point plan:
1. War matériel was to be accumulated in strategic coastal areas of Japan by the end of September. This was to be used by the coastal mobile units for any emergency.
2. Operational war matériel vital to the defense of Japan but not on hand, was to be manufactured immediately. Locations of accumulated matériel distributed for purposes of storage and air defense, would be changed to make the execution of the operational plan easier.
3. In Japan Proper, the Army had no operational line of communications units. All supply depots and medical facilities were under the command of the military administrative organizations (War Ministry). Line of communications activities were quite complicated. Civilian needs were to be rationed and price controls applied in order to obtain vitally necessary materials for the defense of Japan.
4. As it was anticipated that sea transportation would soon be cut between Japan Proper and the Southern Area, fighting strength was to be transferred from China and Manchuria to Japan at the earliest possible moment.
5. Every effort was to be exerted to make Japan self sufficient.
Army-Navy Discussions Regarding a Unified Air Force Command
Ever since June 1942 many investigations had been undertaken and conferences held between the Army and Navy General Staffs of Imperial General Headquarters concerning operational responsibility and cooperation between the Army and Navy Air Forces.
Both the Army and Navy Air Forces were greatly depleted (both in planes and personnel) by the long and exhausting battles that they had fought. The Navy Air Force was responsible for the sea patrol of the Indian and Pacific Oceans, offensive operations in the Northeastern Area and air operations in the Southeastern Area. It had fought long and hard in the Southern Area and during the Marianas sea battle. The Army Air Force was responsible for all operational areas other than those mentioned above and for the defense of Japan Proper. This force also had suffered heavy casualties in the air battles over New Guinea, Burma and China.
In June and again in July 1944, the Navy General Staff recommended that the entire Army Air Force be placed under Navy control in order to provide a more economical use of all air forces under a unified command. While the Army General Staff had no objection to the unified employment of air strength, it pointed out that Army ground operations could not be carried out without supporting air strength. They gave as an example the principal tactics to be used in "SHO-GO" Operation, No. 1 which was an air operation to be carried out against enemy transports under the direction of the Southern Army commander. If the Army Air Force was placed under the command of the Navy, the Army could not carry out this operation. In addition, the Army Air Force bad not been trained for over-water operations.
The Army General Staff felt that the Allies had tremendously improved their air defense methods and that if the Navy persisted in its traditional tactics, the entire Japanese Air Force would be destroyed.
The Army General Staff, therefore, felt compelled to disapprove the Navy General Staff's recommendation. In late July, however, after further discussion, the following plan was agreed upon:
The 1st Air Division, though in the chain of command of the Fifth Area Army, was placed under the operational control of the 12th Air Fleet commander. Through mutual agreement, the Combined Fleet commander was to order the 12th Fleet commander to follow orders from the Fifth
Area Army commander whenever planes were required for air operations over land areas. In air operations over the sea, the 12th Air fleet commander to receive his orders from the Combined Fleet
The 8th Air Division, though in the chain of command of the Formosa Army, was to be placed under the operational control of the 2d Air Fleet for operations over both land and sea.
The 7th and 98th Air Regiments (heavy bombers and torpedo bombers) though in the chain of command of the 1st Air Army, were to be placed under the operational control of the 2d Air Fleet commander.
In the Philippines area, the 4th Air Army and the 1st Air Fleet were ordered to cooperate in all operations whether over land or sea. The 15th Air Regiment (headquarters reconnaissance planes) was to remain under the operational control of the 1st Air Fleet commander.
All Navy air units in Japan which were responsible for air defense operations over land areas only were to be placed under the operational control of the Army Air Force air defense commanders.
Special attention was to be paid to cooperation between the Army and Navy in exchanging technical information.
Measures to Facilitate Railway Transportation on the Continent
In aid-December, Imperial General Headquarters planned a method of flexible control of the continental railway transportation system to meet the needs of the various areas, as well as to support preparations in Japan. The Chief of the Army General Staff was authorised to move the available field railway units in Manchuria and China to
the various commands (China Expeditionary Army, Kwantung Army or Korea Army) according to the requirements of the over-all transportation planning. The Kwantung Army Field Railway Unit was redesignated the Continental Railway Unit (composed mainly of Headquarters, 1st and 3d Railway Commands). The Kwantung Army and China Expeditionary Army railway units then became "floating units" with duties assigned as and when required by the Chief of the Army General Staff. Responsibility was assumed by the commander of the area in which the transportation operation was being carried on, i.e. within the area of responsibility of the China Expeditionary Army, Kwantung Army or the Korea Army.
During this period efforts were concentrated on reinforcing the fighting strength in the Philippines and Nansei Islands. This large-scale transfer of strength necessitated changes in equipment of many of the troops. Transportation and transfer of operational matériel became very complicated. Losses and damage to ships at sea, as well as the bombing of stockpiles of matériel, combined to make it almost impossible to keep en accurate record of the progress of supply operations.
In China, during the final phase of the "ICHI-GO" Operation strenuous efforts under difficult conditions had been made to establish supply facilities in the large operational area. Row, anticipating an enemy attack on the Homeland in the near future, various supply activities were planned and gradually began to be put into effect.
Fifth Phase of the War
(January - August 1945)
Part 1, Situation Prior to "KETSU-GO" Operation
(January - March 1945)
Situation Review and Conclusions Regarding United States Strategy
In the Philippines, on 9 January 1945, the United States Sixth Army landed at Lingayen Gulf. Not only was the strength of the Japanese ground forces inadequate to stage a decisive battle hut the air force was hopelessly outnumbered. General Yamashita was reluctant to advance his main strength to the beaches, believing that he could more effectively destroy the enemy from his prepared positions in the mountainous area in north Luzon. Finally, Imperial General Headquarters ordered the Fourteenth Area Army to advance but, although the Area Army was prepared to obey, enemy air and armored superiority prevented it doing so. Special attack units and raiding parties, therefore, were sent out to wage guerrilla warfare against the enemy landing units and to harass their advance. In addition, the main strength of the Area Army was ordered to fight delaying actions wherever and whenever possible. Hasty preparations for these actions proved far from adequate and the situation in the
Philippines grew steadily worse. It was soon regarded as critical. While delaying actions conducted by the Fourteenth Area Army might pin down part of the enemy forces on Luzon for a short time, the continuous lessening of power of the air force and the inevitable depletion of fuel supplies and ammunition, without any hope of fresh supplies, would soon make delaying actions futile. Strategically, the Philippines were no longer an asset in the defense of Japan.
In Burma, by the end of 1944 the Burma Area Army had completed the reorganization of its positions near Namhkam, Mongmit and Mandalay, tracts along the left bank of the Irrawaddy River and in other key areas in southwest Burma. It put forth every effort to be ready for the next campaign but lack of supplies and the knowledge that it faced an overwhelmingly superior army made the planning of a major interception operation extremely difficult.
In other areas, except for the stepping up of bombing raids by B29's, the situation was quiet. Enemy planes from their bases at Chengtu and the Marianas continued to bomb vital industrial facilities in Manchuria and Kyushu.
In the European theater, the Allies had successfully established a second front in northern France. The failure of German counter-offensives on the eastern front at the end of 1944, followed by a major winter offensive by the Soviets at the beginning of 1945, exhausted Germany's last strategic reserves.
With the almost inevitable collapse of Germany, the attitude of the Soviet Union toward Japan was a matter of growing concern. It was felt that if the Soviet Union judged the time right to strike, it would renounce the Soviet-Japanese Neutrality Pact in order to secure a voice in deciding the future of east Asia.
Imperial General Headquarters' over-all estimate of the situation was that although Japan and Germany had suffered many reverses, the Allies, despite their successes, also had suffered many casualties and that "the final victory will be for those who will stand up against increasing hardship and will fight to the last with a firm belief in ultimate victory."
It was realized that the defeat of Germany would mean the unleashing of a tremendously powerful force against Japan. By the end of 1944 the United States was producing vast numbers of planes, tanks, guns, small arms, motorized vehicles and rocket weapons. In addition, large numbers of troops and many ships now in the European theater soon would be released for use in the Pacific.
Japan estimated that one of the United States major problems would be manpower. With a force of some 11,500,000 already drafted, it was predicted that difficulty would be experienced in obtaining the additional manpower required for industry as well as for army reinforcements. It was hoped that the people, tired of years of war, would advocate the cessation of hostilities.
Imperial General Headquarters, after intensive study of the United States strategy in the Pacific, decided that their probable plan of attack against Japan proper would be to first conduct intensive air and naval operations throughout the Pacific and, after having rendered Japan impotent, to land in Japan at a favorable moment. This would be achieved by (1) isolating Japan from the Continent and the Southern Area (this had been accomplished in part already); (2) exhausting the production resources of Japan and demoralising the Japanese people (by air raids on Japan); (3) by destroying the main air, naval and land forces (the main core of the air and naval forces was destroyed during the Leyte Operation), and (4) advancing land-based fighters so that they could strike at the heart of Japan.
It was felt that the enemy would advance by one of the following two ways:
1. As the invasion of the Philippines progressed, to secure the necessary air bases, they would advance to south China, moving from there to the Nansei Islands. Swatou and Hong Kong seemed the most likely points for their landings. It was expected that these landings would occur late in March, by which time they would have sufficient air strength massed on Luzon to support the landings. The land force to be committed to this operation was estimated to be three or four United States divisions and three British or Australian divisions. About five divisions would attempt an invasion of the Nansei Islands during or shortly after June.
2. After completion of the Philippines invasion, the United States forces would attempt to move forward to Formosa, the Nansei end Ogasawara Islands and Iwo Jima, instead of south
China. Bases would be established on these islands from which bombing operations would be directed against Japan. At the same time, they would prepare for a major amphibious operation against Japan.
It was considered likely that the enemy might first aim a drive against strategic points in north Formosa in order to destroy Japanese air bases located there. This would prevent attacks against their forces invading the Nansei Islands. Enemy air bases would be advanced to points where they could be used in operations against Shanghai and the Nansei Islands. The time for the landing operations was estimated to be March or April for Formosa and May or June for Okinawa. Strength of the invading forces was expected to be about four divisions.
Believing that the United States planned to terminate the war as quickly as possible, Imperial General Headquarters felt that they would most likely take the second alternative as the shortest route toward mounting an invasion against Japan, particularly as already all Japanese supply routes to the south had been cut. In addition, radio intelligence reported that there were very definite indications that the enemy was planning to attack Iwo Jima in the very near future.
The Threat from the Soviet Union and China Increases Relations between Japan and the Soviet Union were strained to the breaking point. It was felt that much depended on the progress of the war against Germany and the Allies success in Asia. It was estimated that the Soviet Union would declare war on Japan in the summer or fall of 1945, by which time the United States would have
completed preparations for the invasion of the Homeland. The Soviet Far Eastern Army was expected to move against Manchuria, Korea, north China and Karafuto (Sakhalin) and to occupy all vital points in these areas.
The Nationalist Army in China was rapidly being remodelled after the American pattern and, as its strength increased, it was estimated it would embark on major offensives in the Hunan and Kwangsi Provinces. The total strength of this force, including nine Americanised divisions, was expected to be about 24 or 25 divisions. Indications were that an offensive would be launched about July or August in concert with an Allied invasion of the China coast.
Review of Japan's Manpower and Matériel
At the end of October 1944, the total strength of the reservists, which formed the main reservoir of manpower for military mobilization, was some 6,390,000 men. Of this number 4,690,000 were ready to be called for active duty. Imperial General Headquarters estimated that it would require in the vicinity of 40 divisions with the attendant line of communications units (1,500,000 men) to complete Japan's defenses, while on paper, it appeared that there was adequate manpower to fill these needs, there was a serious lack of trained personnel, particularly in the field of technical services such as engineering and signal. Furthermore, some 87% of the total adult population had been drafted into the food and munitions industries, which were of
primary importance in maintaining war supplies and minimum subsistence for the people. Of this production manpower approximately 47% belonged to some class of the Reservist Army. Thus, in order to effectively and systematically employ the available manpower, it would be necessary to draw up an over-all plan for proper coordination between military and labor mobilisation, otherwise many industrial activities would come to a halt.
To meet the pressing needs of the war in the Pacific over the years a large number of ships had been requisitioned but, by early 1945, most of them had been lost or severely damaged. The supply of natural resources from overseas had been sharply cut, with the consequent drop in production of military matériel. Added to this was the stepping up of enemy bombings of Japan's industrial installations to the point where production was almost at a standstill.
Basic production as planned for 1945 was: 3,000,000 tons of steel; 40,000 airplanes; 1,500,000 tons of steel ships, and 1,650,000 kiloliters of liquid fuel from Manchuria, China and Japan. Although these quotas were far lower than planned for 1944 (in fact, the quantity of liquid fuel was about half that planned for 1944), it was still more than actually had been produced during that year. Steel to be allocated to the land forces in 1945 was about 60% of that for the previous year. Production of aircraft was the only field in which greater numbers were planned.
With the reduced production it was impossible to fulfill the requirements of the Army fighting on widespread fronts. There were many problems to be solved, such as: unified control of requisitions for the Army and Navy; standardizing designs for weapons; simplification of supply procedures and exhaustive research to find unexploited resources. It would be necessary to make the utmost use of any and all matériel available from any source whatsoever. Troops were instructed to exert every effort to repair and maintain all available equipment and matériel.
Imperial General Headquarters' Operational Plans (January 1945)
All hope was gone of turning the tide of war in the Philippines. It was now necessary to prepare for a last ditch stand in Japan. Lack of matériel power must be compensated for by the strong determination of the Japanese people to sacrifice themselves for the sake of their country. Every terrain advantage and the combined actions of the entire population would be used to fight to the finish. After daily deliberations, in late January Imperial General
Headquarters published the following policy:
Whenever the opportunity presents itself the invading enemy will be crushed, most particularly the United States forces. Defense positions in depth will be constructed around the Homeland where the enemy will be intercepted and every effort made to destroy their determination to continue fighting. In the Pacific and East China Sea areas, which it is estimated will form the main battle fronts against the expected invasion by the United States forces, defense preparations will be speeded up.
Operations on the China mainland will be conducted with the idea that the United States forces are the principal enemy. At the same time, the Japanese Army in China will exert every effort to destroy the Chungking Army. In order to meet expected enemy attacks along the southeast coast of China, the China Expeditionary Army will reorganize its battle fronts. In addition, operational preparations against probable United States landings in the lower reaches of the Yangtze River end at Canton will be completed by early summer of 1945.
Every effort will be exerted to hold Formosa and the Nansei Islands in order to deny the enemy their use as air end sea bases from which to attack Japan. In addition, Formosa and Okinawa, in particular, will be used as bases from which the Japanese Air Force will operate in the East China Sea.
Operational preparations on the Homeland and Korea will be strengthened rapidly and fully at all costs. Intensive air raids by the United States Air Force are expected. Methods to deal with these raids will be established immediately.
The Homeland Group, consisting of the Kuril Islands, Karafuto (Sakhalin), Hokkaido, Honshu, Shikoku, Kyushu end the neighboring islands of Tanegashima and Yakushima will be firmly secured.
Chief emphasis for Homeland defense was to be placed on the Kanto, Kyushu and Tokai (Nagoya) districts. First priority was to be given to air defense in these districts and in the Osaka-Kobe area.
An air-warning system was to be set up so that enemy planes could be intercepted and destroyed before they reached Japan. In addition, the Army and Navy Air Forces were to cooperate fully with
the Navy in attempting to destroy enemy landing forces while still at sea.
In Korea, on 11 February 1945, the Seventeenth Area Army was established with the mission of defending the peninsula, including Cheju-do. In addition, it was directed to stress the defense of the main railway line extending the length of the peninsula, the north Korea railway and certain key sectors along the Tumen River.
With the fast deteriorating situation in the Philippines, the Southern Army was ordered to concentrate its efforts on holding strategic tones in Indo-China, Thailand, Malaya and Sumatra and to destroy the attacking enemy wherever and whenever possible. From these positions, the Southern Army was to exert every effort to stop the advance of the enemy to China and Japan. In the Philippines, the defenders were to endeavor to hold key positions on Luzon and to launch effective delaying actions.
During the early stages of the war the center of military operations had been in the overseas area. The main strength of the Japanese Army had been stationed at strategic points on the Asian continent or on outlying islands. Subsequent developments had made it necessary to withdraw these troops toward Japan and place them in new defense lines to protect the Homeland. The tide of war turned against Japan so quickly, however, that it became impossible to withdraw many of the forces stationed in the Southern and Central Pacific Areas.
Imperial General Headquarters was raced with many problems. Some of the most difficult of these were: future relations with the Soviet Union; how to achieve the defense of the Homeland with its poor fighting potential and how to accomplish urgent operational preparations in the short time at its disposal.
It was recognised that diplomatic and not military maneuvers were the only hope of maintaining the status quo with the Soviet Union.
In January 1945, Imperial General Headquarters decided to mobilize an additional force of approximately 40 divisions, 20 independent mixed brigades and the accompanying organic units for the purpose of defending the Homeland. Even so, it was felt that this could not create sufficient strength to defend Japan. It was planned, therefore, to draw further strength, especially officers, from Manchuria and China. It was recognized that this would greatly weaken these areas but the pressing need to prepare to defend the Homeland demanded that most drastic action be taken. Not only was Navy surplus matériel commandeered to bolster dwindling stocks but munitions and matériel stored in Manchuria were ordered shipped to Japan.
The plan by which it was hoped to raise the military strength to the desired level included five main points. They were:
1. The enlargement and reinforcement of air attack and air defense forces was to be given first priority in military preparations.
2. Production of special attack weapons and the training and organisation of capable personnel to man these weapons was to be undertaken immediately.
3. The primary aim was a well-trained, well-equipped force, although it was realized this might result in a force of limited size. In addition, a second force, composed mainly of civilians, probably poorly armed, would be formed.
4. The armies in Manchuria and China were to increase their self-sufficiency so that they might continue to fight without outside assistance.
5. Strong and effective administrative measures were to be adopted to strengthen the fighting power and morale of the Army.
Establishment of a Civil Defense Plan
It was planned to divide the District Army Headquarters in Japan into an operational and administrative army headquarters. The Area Army commander was to be responsible for operational preparations while the Administrative District commander was to be responsible for all military administrative activities, which would necessarily have close contact with many phases of civil administration. This was planned in order to relieve operational troops from any nonessential duties which might interfere with the execution of their purely operational activities. At the same time, it would consolidate the preparedness of the whole country for battle by firmly welding together both military and civilian forces.
Actually, the commander of each Area Army assumed the dual responsibility of administration and operations - but under different
titles. To support him through the chain of command in organizing the Homeland civilian reserve force the position of Divisional District commander was established. Under the Divisional District commander were Guard District commands and Local Defense Units commands. The Guard District commands were of two types, according to the location of the command. Type "A" were assigned to suburban and rural prefectures while Type "B" were assigned to such cities as Yokohama, Nagoya, Kyoto, Osaka and Kobe. Tokyo, because the Imperial Palace was located there, also because it was the seat of government, was excluded from this general plan.
Among the units to be organized were first in line of experience members of the regular Guard Units, who served as full-time soldiers in training and actual duty. Next in line of military qualified troops were the specially established Guard Units, composed of personnel who had had combat experience but had since returned to civilian life. Members of the specially established Guard Units were to be authorized to continue work at their civilian Jobs as well as being members of the civilian defense force. Finally, there were the Local Defense Units, composed of personnel without any military training or experience whatsoever. They too were to continue with their civilian work in addition to being responsible for military duty.
Another phase of the civilian reserve mobilization was the replacement units under each divisional district commander. Personnel
undergoing training in these units were subject to call for service with operational units.
In the case of actual ground battles, both types of Guard Units were subject to call for operational army service as units but not as individuals.
Operational Army Mobilisation Schedule
To effect quick reinforcement of battle positions, an emergency mobilisation plan for Homeland operational forces was established in early February. It placed the headquarters of the Eleventh, Twelfth, Thirteenth, Fifteenth and Sixteenth Area Armies at Sendai, Tokyo, Nagoya, Osaka and Fukuoka, respectively. In addition, four independent mixed brigades were to be activated and placed at likely enemy landing points.
The First Group Operational Army Mobilization Plan, which was to be accomplished from late February through March (actually completed 8 April 1945) using depot divisions as a nucleus, resulted in eighteen combat infantry divisions being activated. These were: 13 for Honshu, Shikoku and Kyushu (140th, 142d, 143d, 144th, 145th, 146th, 151st, 152d, 153d, 154th, 155th, 156th and 157th); 3 for Hokkaido, Karafuto and the Kuriles (88th, 89th and 147th) and 2 for Korea (150th and 160th). The primary mission of this group was to guard strategic zones along the coastline and insure the holding of sections of the coastline for operations by rear echelon attack forces. Their first task was to construct necessary fortifications.
The Second Group Operational Army Mobilization Plan was developed in April and carried out for the most part in May. It consisted of eight well equipped mobile infantry divisions (201st, 202d, 205th, 206th, 209th, 212th, 214th and 216th) of the best personnel possible under the current manpower situation; six independent tank brigades and five tank regiments. In addition, a force of four strong divisions (1st Tank Division, and 11th, 25th and 57th Infantry Divisions) and three well-trained divisions (111th, 120th and 121st) were to be transferred from Manchuria to the Homeland and Korea respectively. The primary mission of this group was to fight the last decisive battle.
As part of the mobilization, on 15 April, two General Army Headquarters, an Air General Army and nine Army Headquarters were established. Because it was realized that the task of defending Japan was too great for one defense headquarters, the General Defense Command was inactivated and the country was divided into two large defense areas under the Chief of the Army General Staff, who, in turn, assigned them to the First (East) General Army Headquarters and the Second (West) General Army Headquarters.
The Third Group Operational Army Mobilization Plan was developed in May and carried out during the latter part of May through June. This called for sixteen new divisions (221st, 222d, 224th, 225th, 229th, 230th, 231st, 303d, 308th, 312th, 316th, 321st, 322d, 344th,
351st, and 354th) for the Homeland. Of these, nine were to be coastal defense divisions and seven mobile divisions. Later, the 234th and 355th Divisions were activated - the first for coastal defense and the second as a mobile division. About the same time, the 320th Division was activated for Korea. In addition 14 mixed brigades and 5 mixed regiments were formed, plus a number of composite units centered around artillery units. These last units were used to reinforce both coastal defenses and mobile fighting strength.
The main reason that the Mobilization Plan was realized in three groups was that the state of the supply potential, both manpower and matériel, made the simultaneous activation of all operational forces impossible. Priority was given to those vital zones which had to be speedily fortified and strongly manned for strategic reasons. These zones were also given top priority for procurement of necessary war materials.
Lack of the necessary equipment made it impossible to mobilize the required line of communications units, but it was hoped that some units would arrive from Manchuria. In the Homeland itself, line of communications units would be limited to those directly needed by front-line units. Most of the rear echelon services were to be left in the bands of drafted civilians since the final battles would be fought in Japan.
The total strength of the line of communications units being
considered for mobilization consisted of independent motor transport battalions or companies, independent animal transport battalions or companies and various other duty units as the core force, amounting to some 400,000 men. They were to be equipped with approximately 12,000 motorized vehicles, 470,000 horses and 70,000 transport carts. As the Army had no new motor vehicles to spare for this purpose, it was planned to requisition them from among the 35,000 civilian cars, of which 24,000 were known to be in operating condition. One-seventh of all horses in the country were to be requisitioned. The Army would be able to furnish approximately 20,000 transport carts but the additional 50,000 carts would have to be built or requisitioned by troops in their responsible areas.
Southern Army Operations
Although the strategic value of the Southern Army had greatly diminished after the defeat in the Leyte Campaign, it was hoped it would still be able to help general operations designed to check the enemy's invasion of Japan. To this end the basic missions of the Southern Army were revised. Strong measures were to be taken to secure and stabilize French Indo-China, which was the most important area in which to maintain the self-sufficiency of the Southern Army. Matériel and personnel essential for the defense of the Homeland (fuel, air units and personnel for mobilization of new air units) were to be sent back to Japan. At the end of January, after careful study, Imperial General Headquarters published revised orders for the Southern Army.
The Southern Army Commander in Chief was ordered to destroy the attacking enemy and to secure important sectors so as to check the enemy's advance toward China and Japan. He was to secure strategically important positions on Luzon in the Philippines, as well as in Indo-China, Thailand, Malaya and Sumatra, which were now the pivots of the Southern Area. In other areas, the Southern Army was to secure those areas which were regarded as important either strategically or politically, especially those districts containing essential natural resources and those bases the enemy appeared most anxious to capture. The enemy's fighting strength was to be attacked aggressively and, whenever possible, their supply lines were to be harassed and disrupted with special attention being given to cutting their important sea communication routes. Special attention was to be given to military administration in accordance with existing conditions and the people in the south were to be indoctrinated as to the purpose of the war.
Directives were issued instructing the Southern Army in the methods to be used in regard to lines of communications, especially stressing the fact that the Southern Army could not rely on receiving supplies and reinforcements from the Homeland due to the dangers encountered by sea transportation. It was to become self-sufficient by strengthening transportation facilities in French Indo-China, Thailand and Malaya, which were the supply centers for the Southern Area. Munitions in the Southern Area were to be concentrated in
central locations conveniently accessible to units in the area. As much national defense matériel as practicable was to be sent back to Japan. Military administrative measures were to support operational plans and every effort was to be made to win the confidence of the people.
Although the Southern Army, in cooperation with the navy, made every effort to penetrate the enemy's blockade in order to send back vital strategic materials to Japan, it was estimated that only about half the shipments arrived - the rest were sunk.
On 1 February, the United States Army began its drive from Lingayen Gulf and the Batangas area and, by the 3d, had reached the northern outskirts of Manila. It was not, however, until 3 March that organized resistance in the city finally ceased. In the meantime, the Fourteenth Area Army continued persistent and vigorous delaying actions from the mountainous area in northern Luzon, the sector west of Clark Field and the area east of Manila.
By the end of May, enemy forces in the Philippines were estimated to be in the vicinity of ten well-equipped divisions on Luzon, in addition to divisions deployed on Panay, Negros, Masbate, Cebu, Palawan, Jolo, Tawitawi and Mindanao. Moreover, they had approximately 2,000 first-line planes in the area. In the face of this overwhelmingly stronger force, with an almost impossible situation in regard to supplying the troops and with casualties steadily mounting, the Fourteenth Area Army found it impossible to carry out
further effective activities. To add to the problems of an already critical situation, enemy guerrilla activities increased tremendously.
In north Burma, the situation was causing the Southern Army grave concern. In mid-February, enemy strength in the vicinity of Myitson had been greatly reinforced and the 33d Army, which had suffered many casualties, was forced to withdraw. At the end of the month the Burma Road Operation was abandoned. About the same time, a powerful enemy armored force crossed the Irrawaddy River and advanced to Meiktila. The Burma Area Army, by now short of supplies, was unable to destroy this force, which was receiving its supplies by air. The Area Army, therefore, was forced to retreat and readjust its battle lines. In addition, on 27 March, about 8,000 troops from the National Army of Burma revolted against the Japanese Army and part of the Burma Area Army was required to quell uprisings in various parts of Burma.
On 7 April, in view of the deterioration of the situation in both Indo-China and Malaya, the Southern Army charged the Burma Area Army with securing the important areas around Rangoon, Toungoo and Loikaw, but before the Area Army could change its troop dispositions, on 2 May the enemy made a surprise landing at the mouth of the Rangoon River. Rangoon was undefended and, on the 3d, the enemy occupied the town.
With the growing importance operationally of Thailand, French Indo-China and Malaya, in an effort to strengthen these areas, in mid-January the Southern Army diverted the 2d and 4th Divisions from Burma and Sumatra respectively to Thailand to reinforce positions on the peninsula. Shortly afterwards the 2d Division was transferred to French Indo-China. In addition, the 46th Division was transferred from Flores Islands to Singapore to strengthen that sector. At the end of January, Imperial General Headquarters ordered the 22d and 37th Divisions to advance to north French Indo-China from the China area and, by the end of February, these two divisions had arrived in the area. At that time, preparations for the control of French Indo-China were regarded as progressing satisfactorily.
Local forces had maintained peace and order in French Indo-China until, on 28 February, orders were issued to the Southern Army to assume military control of this area as it was felt that many sympathized with DeGaulle and that the attitude of the French Indo-Chinese was gradually turning against Japan.
There was a danger that United States forces might land in this area and that the French Army in French Indo-China might Join them.
On the morning of 9 March, the Japanese Ambassador to French Indo-China presented the following request to the Governor-General of French Indo-China:
In view of the general situation and especially the fact that United States forces are launching carrier plane strikes against French
Indo-China, Japan requests the Governor-General to resist the United States forces with his Army and to cooperate with Japan in accordance with the Joint Defense Agreement. To accomplish this, Japan requests the Governor-General to agree to the following:
The French Indo-Chinese Army and the armed police will be placed under the control of the Imperial Japanese Army for the duration of the present situation. They will obey Japanese commands in relation to organisation, disposition and movement of units, ammunition and materials. All transportation, shipping and communication facilities which are necessary to carry out the military operations will be placed under the command of the Imperial Japanese Army.
The Governor-General will order all governmental agencies and the population of French Indo-China to cooperate wholly and faithfully with the Imperial Japanese Army.
The Governor General refused these demands through diplomatic channels. The Southern Army Commander in Chief, therefore, took military action to enforce them.
The same day, the Southern Army took the offensive and, the following day, was in control of central and southern Indo-China. There was unexpectedly strong resistance in the north, but Hanoi and Hue were occupied on the evening of the 10th and Langson on the 14th.
Japanese troops began disarming and disbanding the French Indo-China Army, as well as security and police units. The Southern Army
took control of railways, shipping and communications. In the main areas these military measures were completed by the middle of March when the Army turned to suppressing elements in the mountains in northwestern and central French Indo-China.
During this time there was no appreciable change in the situation in Thailand.
Operations in the Central Pacific, Formosa and the Nansei Islands
From the beginning of February, movement of enemy convoys in the Marianas and Ulithi waters grew increasingly active. Taking off on 12 February from their bases on Ulithi and the Marianas, heavily protected by their carriers, enemy invading forces approached Iwo Jima on the 16th.46 On the 19th, after the southern shore of the island had been subjected to severe naval bombardment, the American troops landed.
The total Japanese garrison force on the island was about 23,000 strong, consisting mainly of:
Main body of the 109th Division Headquarters
2d Mixed Brigade
145th Infantry Regiment
3d Battalion, 17th Independent Mixed Regiment
26th Tank Regiment
1st & 2d Independent Machine Gun Battalions
8th & 12th Independent Antitank Battalions
2d & 3d Medina Mortar Battalions
20th Independent Heavy Mortar Battalion
One Navy unit of approximately 1,500 men
These troops were supplied with about 60% of the standard issue of ammunitions sufficient for one engagement by one division and approximately four months' rations and forage.
At first the enemy landed about one division with some 200 tanks. This force, however, was steadily increased until, by the end of February, it was estimated that there were three Marine divisions on the island.
When the enemy landed, the garrison forces resisted with bitter determination but, despite desperate efforts, they were gradually overcome by the enemy's enormous matériel superiority. On the 23d, the powerful positions manned by the naval garrison unit on Mt. Suribachi fell and part of the main defense line was lost to the enemy. During the fighting for this hill, almost the entire unit was wiped out. An instance of the enemy's matériel advantage was that in one day in late February it was reported that they had fired approximately 30,000 rounds and made over 100 air sorties.
From 23 February until 3 March, the Japanese and United States forces fought desperately over every inch of land in the main defense zone in the central sector.
The enemy landing force, supported by the United States Fleet surrounding the island, and the United States Air Corps, which had already begun using the land bases, continuously attacked with its superior artillery and tanks, sweeping all resistance before lt.
The Japanese garrison fought gallantly, sending out raiding parties and repeatedly attempting to counterattack. All their efforts, however, were futile. On 5 March, therefore, the main strength of the surviving force gathered in a redoubt in the northern sector and prepared for the final battle. On the 13th, elements of the United States forces penetrated this redoubt and the Japanese unit destroyed its regimental colors. Finally, on the night of 17 March, the commander and the remaining officers made a final charge and all died fighting. By the end of the month, most of the Japanese troops scattered around the island had been destroyed and the United States forces had completely occupied the island.
Because of the critical situation on all fronts it had not been possible to spare sufficient sir support for the Iwo Jima action. All that the commander of the Homeland defense could do was to send a small part of the 6th Air Army, which made a futile attempt to check landing operations.
As it was now almost certain that the United States forces would next attack the remaining Ogasawara Islands, Lt. Gen. Yoshio Tachibana, commander of the Chichijima Garrison Unit, took command of these islands.
After 1 April, the 14th Division, which was garrisoning Palau, made repeated attacks against the enemy naval forces operating in the waters near Peleliu and, up till mid-June, scored many gains.
To rebuild the strength on Formosa after the transfer of the 68th Brigade and 10th and 23d Divisions to the Philippines at the end of 1944, in January 1945 the 40th Army Headquarters was set up and five independent mixed brigades were activated on the island. In addition, one division each was sent from China, the Nansei Islands and Manchuria. By the end of February, the ground force on Formosa was five divisions and six brigades.
To fill the gap in the defenses of Okinawa caused by the transfer of the 9th Division to Formosa, the Army General Staff at first considered sending the 84th Division from Japan, and some munitions were shipped while the plan was still being studied. Actually, the division was not shipped as some members of the Army General Staff felt that the move was strategically unsound. Lessons learned from battle experience in the past showed that in spite of being strongly fortified these outlying islands were extremely difficult to hold and it was felt that it would be far better to strengthen the defenses on Japan itself. At this time, even the general defense plan for the Homeland had not been completed.
On 3 February, the Tenth Area Army commander received an order from Imperial General Headquarters commanding him to block every attempt by the enemy, particularly the United States Forces, to
advance their sea and air bases toward Formosa and the Nansei Islands. In order to facilitate operational preparations in the important areas in the vicinity of the Homeland and on the Homeland itself, Formosa and Okinawa in particular were to be held at all costs. This was vital in order to preserve bases for the conduct of future air operations over the East China Sea. These air operations would be coordinated with those from bases on Kyushu, southern Korea and the lower reaches of the Yangtze River. Should the enemy land on the southeastern China coast, the Tenth Area Army was to assist the China Expeditionary Army by destroying the enemy convoys at sea with its air forces.
Agreements regarding the principle points of cooperation were reached by the Army and Navy in support of this order. In general, the Army would be responsible for the land defense of Formosa and the Nansei Islands, while the Navy would be responsible for sea defense. In carrying out land operations, the Tenth Area Army commander was authorized to command as many naval land units stationed in Formosa and the Nansei Islands as he required. However, necessary negotiations were to be conducted with the Commander in Chief of the Sasebo Naval District and the Commander in Chief of the Takao Naval Guard District as to how many and which naval land units were to be used for this purpose.
Preparations and Disposition of Forces in Korea, China and Manchuria
The Korean defense plan had to include a dual strategy, setting up a bulwark in southern Korea against the Allied Forces and another in northern Korea against the Soviets. The various phases of the Operational Army Group Mobilization Plans provided the means for this. Three new divisions were to be created immediately. The 19th Depot Division was to be reorganized into the 79th Division and stationed in northern Korea. The 96th Division was activated in Korea and placed on duty in the south. The third division, however, which was to have been organized in Japan, did not eventuate. At the same time, five divisional district headquarters were to be established. During the First Group Mobilization in Japan, one Army Headquarters (58th) and two divisions (150th and 160th) were to be organized. During the Second Group Mobilization, three divisions (111th, 120th and 121st) were transferred from Manchuria to Korea. During the Third Group Mobilization, two divisions (320th and one other, for which the 127th Independent Mixed Brigade was later substituted) were to be activated.
Generally speaking, the disposition of forces in Korea was governed to a large extent by the direction of operations in subsequent stages of battle on the continent. This was especially true of the development of anti-Soviet defense plans. As a result, efforts were to be made to preserve a certain measure of flexibility readily adjustable to any emergency.
The program of battle preparations in China was extensive and varied. Some of the more urgent problems to be solved were: methods to firmly secure a number of strong air bases in China from which to operate in protecting vital bases linking China. Manchuria and Japan; preparations to beat back any enemy attack against the southeast coast of China; ways to make a speedy disposition of necessary forces to maintain peace and order, and to organize and hold ready the entire reserve force of the Army so that it could be moved quickly to the Manchurian front in case of an emergency. Late spring or early summer of 1945 was the target date for the occupation of all captured zones to be completed and the foundation for the planned strategy firmly established. It was estimated that, by making whatever required revisions or replacements necessary in the buildup of forces, by the summer of 1946 there would be such a strong military setup on the continent that it would be invulnerable to any invasion.
The objective was to raise the strength of the operational group by the end of 1945 to 20 fully equipped divisions; the force to preserve peace to 20 partially equipped divisions; the special guard force to six divisions; mixed brigades to 17; and the force to guard transportation routes to 50 battalions. By the middle of 1946 it was hoped to strengthen and reorganize eight of the 20 partially equipped divisions into fully equipped divisions. In addition, the number of guard battalions was to be enlarged to 110.
In actual fact, the total strength of the forces stationed in China at the end of 1944 was 25 regular divisions, one tank division, 10 independent mixed brigades and 11 independent infantry brigades.
With the threat of United States forces landing in China and increasing difficulties in surface transportation, measures were taken toward reinforcing southeastern China. Sufficient troops were assembled in Japan for approximately three divisions. They were provisionally organized and hurriedly shipped to China. There, with field replacement units being used as a cadre, the three new divisions, as well as 12 mixed brigades, seven guard units and accompanying organic units were activated. Simultaneously, the main strength of the forces in China began to converge toward the triangular zone in central China. To direct this operation, the Sixth Army Headquarters was transferred from Manchuria.
As the situation grew more tense in the Pacific Theater, one after another the 1st, 8th, 9th, 10th, 12th, 23d, 24th, 28th, 29th and 71st Divisions and the 2d Tank Division had been transferred from Manchuria to that theater. In addition, it was recognized that considerably more strength would be drawn from Manchuria in the near future to bolster the Homeland forces.
To cope with a greatly weakened Kwantung Army facing a possible Soviet invasion, the Army General Staff adopted a policy of increasing the number of personnel within the divisions as well as activating divisions in Manchuria. This was to be done by mobilizing Japanese civilians who had long been residents in this area. The objectives of this policy were to discourage the Soviet Union from entering a war against Japan by creating the impression of a strong army in Manchuria; to make available to the Kwantung Army troop strength which could be used as a reservoir from which Japan could draw its required reinforcements, and to make the Kwantung Army strong enough without outside help to fight a Soviet invasion which it was Judged might be launched in the summer of 1945 should the tide of war continue to turn against Japan.
At the beginning of 1945, therefore, the 3d Cavalry Brigade and some border garrison units were reorganized into eight divisions and four mixed brigades. Simultaneously, an operational group of four fully equipped divisions was transferred to Japan, while two partially equipped divisions were transferred to Korea. In addition, about one-third of the total equipment and war matériel on hand for the Kwantung Army, together with a unit of key personnel required by the General Defense Command, were transported to Japan.
Lines of Communications (Logistical Support) During this Period
During the past seven years of continuous fighting, beginning with the China Incident, Japan's stockpile of matériel had been greatly depleted and all resources had been exploited to the utmost. As time passed it became increasingly difficult to meet even the current requirements of the fighting forces and practically impossible to conserve the national defensive power so that reserves would be available for a last-ditch stand on the Homeland. In addition, with the fall of the Philippines, supply routes to the Southern Area to all intents and purposes had been severed.
In an effort to cope with the situation, all overseas armies were instructed to make every endeavor to become self-supporting and to live off the land over which they were fighting. In Japan all efforts were concentrated on stockpiling matériel from whatever sources were available and assembling fighting strength in the strategic zones of the Homeland. It was decided that supply preparations in the rear areas would be completed roughly by June 1945 and thoroughly by the end of October. Priority was to be given to the Kanto, Kyushu and Shikoku areas where preparations were to be completed by the middle of the year. In addition, the production of equipment for air combat preparations was to be completed by the end of June. An outline of the supply plan was as follows:
The war potential will be built to the maximum during the first half of 1945 and as much strength as possible will be transferred from the Continent to the Homeland.
The Army will cooperate in increasing food and fuel production.
In view of the increasing difficulties in land and sea transportation, each Army district will endeavor to establish local self-sufficiency. In this connection, emphasis will be placed on achieving self-sufficiency in food supply, repair of equipment and production of part of its equipment and fuel needs.
Dispersal and camouflage will be carried out so as to reduce losses from bombing attacks to a minimum.
Priority in equipment will be given to coastal defense units and those units disposed in the Kanto and Kyushu areas.
Priority in the supply of aircraft will be given to fighter units directly covering special attack units, interceptor units and other units in this order.
In order to conserve shipping space, units being transferred from Manchuria will leave behind their horses and non-essential equipment. However, they will bring back with them ammunition for a major engagement, two weeks' supply of fuel, a month's supply of provisions and as much fortification material as possible.
The basic plan for handling war matériel for operational purposes in the earlier stages of the preparations were as shown on Chart No. 13.
Homeland Operations and Strategy
During the early part of February the Army General Staff laid the ground work for strengthening the defenses of Japan and Korea by a series of orders to the armies clarifying command responsibilities in Formosa, Nansei Islands, China and the Southern Area, as
Chart No. 13
Plan for Reimporting War Matériel from Manchuria to Japan and Korea
Destination Description Quantity Amount to be Shipped Remarks Mar Apr May Jun Jul Aug Japan Fuel (1,000 kiloliters) Aviation Gasoline 17 12 5 Provisional program of debarkation is as follows:
Ordinary Gasoline 20 8 7 5 Light Oil, Lubricating Oil, etc 10 <- - -> Ground Ammunition Sufficient for 10 engagements by one division <- - - -> South Korea Aviation Gasoline 3,000 kiloliters <- - - -> Transported to Heijo area Ground Ammunition Sufficient for 5 engagements by one division <-- 3 -> <-- 2 --> Remarks: a. Order of priority in transportation will be: First: fuel (especially aviation gasoline); second: ground ammunition.
b. In addition to matériel mentioned above, efforts will be made to reimport railroad and river-crossing materials, materials to be used in close combat, anti-tank materials, and preservable foodstuffs.
c. Estimate of weight of goods to be transported indicated that ground ammunition sufficient for 1 engagement of division weighed approximately 2,000 tons.
d. The above list is subject to change.
well as the command of general air operations in the Eastern China Sea area.
On 6 February 1945, the three amy command headquarters were inactivated and five area amy headquarters and five military district headquarters were established. The area amy headquarters assumed responsibility for operational missions and the military district headquarters for military administrative matters. These headquarters under the command of the Homeland Defense Army were:
Northeastern Military District Eleventh Area Army Sendai Eastern Military District Twelfth Area Army Tokyo last Coast Military District Thirteenth Area Army Nagoya Central Military District Fifteenth Area Army Osaka Western Military District Sixteenth Area Army Fukuoka
In addition, three mom area armies, together with an equal number of military district commands, were activated under the direct command of Imperial General Headquarters. These were:
Northern Military District Fifth Area Army Sapporo Korea Military District Seventeenth Area Army Keijo Formosa Military District Tenth Area Army Taihoku
Since it was obvious that operational preparations could not be carried out independently of general administrative activities, the commander and staff of the area amies concurrently held the same posts with the military districts. It was hoped by this method to increase efficiency and obtain quick decisions.
At this time, the orders of battle of the General Defense Army and the Seventeenth Area Army were issued and these two amies were
ordered to move immediately into battle positions. The Northern, Formosa and Korea Military District commanders were placed under the direction of the Fifth, Tenth and Seventeenth Area Army commanders respectively in all matters pertaining to operations. The commander of the General Defense Command was entrusted with the mission of directing activities of the Seventeenth Area Army in aerial operations and protection of surface transportation. Simultaneously, orders were issued to both the commander of the General Defense Command and the Seventeenth Area Army commander to beat back any invading enemy and guard the Homeland and Korea.47
The main points of the operational order issued to the commander of the General Defense Command were:
Operational preparations in Japan will be stressed particularly in the Kanto, Kyushu and Tokai districts. Special emphasis will be placed on the air defense of key points in the foregoing sectors and the Osaka-Kobe district.
In addition to intercepting enemy air raids at an opportune time, the Commander in Chief of the General Defense Command will cooperate with the Navy in exerting every effort to destroy the enemy task forces attacking in the vicinity of Japan.
Efforts will be made to destroy the enemy at sea so as to prevent an invasion of the Homeland.
Protection of land transportation routes and harbor installations will be maintained with special emphasis being placed on guarding key points of surface transportation between Japan and Korea.
The Navy will be given as much assistance as circumstances will permit in the protection of surface transportation.
The main points of the operational order issued to the Seventeenth Area Army commander were:
In putting into effect the necessary preparations for defensive operations against an anticipated Soviet attack, the Seventeenth Area Army commander will come under the delegated command of the Commanding General of the Kwantung Army.
Operational preparations in Korea will be stressed around the key sectors of south Korea (including Saishu Island).
Key points of the trans-peninsula railroad (running the length of Korea), north Korean railway and the Ya-Lu and Tou-Kou rivers will be guarded strongly.
These orders were delivered personally to the commander of the General Defense Command and the various Area Army commanders, who were in Tokyo in early February. On this occasion, the Chief of the Army General Staff emphasized the necessity for each headquarters to be thoroughly familiar with all aspects of the plan for conducting the battle for the Homeland. He urged thorough training of each army, speedy accomplishment of all preparations, the intensifying of intelligence activities, maintenance of transportation
and communication facilities, conservation of war matériel and equipment and a diligent application of effort by staff officers to complete all preparations.
In the Southern Area, part of the Army forces had been shifted from Burma and the Sunda Islands to Thailand and Malaya. In March, in order to consolidate defense positions in the vital area of French Indo-China, Japanese forces there had disarmed the French Indo-China Army and occupied French governmental installations. By mid-June radio communications with the Philippines had ceased. The Burma Area Army had suffered still further reverses along the Irrawaddy River and, in early May, with the fall of Rangoon, the main forces were forced to withdraw to strategic areas in southern Burma.
In the China theater, by 26 January, the China Expeditionary Army had captured the entire line of the Canton-Hankou railway and, by 8 February, had occupied all airfields in the Suichuan-Kanhsien sector. Strong enemy air forces, however, continued to harass the Japanese forces and to strike at the railroads and motor highways in north and central China, and the Yangtze River and Hsiang Chiang in central China. It was known that the enemy was receiving large air shipments of munitions and personnel and it was felt that they planned to launch a major counteroffensive in the near future. In an effort to check the enemy sir force, therefore, Imperial General Headquarters ordered the China Expeditionary Army to destroy the
enemy airfields in the Laohokou and Chihkiang sectors. On 22 March, 12th Army units opened a general offensive and, by the 27th, had captured Laohokou airfield, but it was not until 8 April that the town was occupied. On 3 April, the 20th Army launched an attack to capture Chihkiang. Large enemy reinforcements arriving in the area and a superior air force prevented the 20th Army from achieving its objective and, on 9 May, orders were received from the China Expeditionary Army to suspend the operation.48
From February onward the Army General Staff continued to study plans for strengthening the defenses of the Homeland. Considerable progress had been made in mobilisation and disposition of the forces of the General Defense Command, completion of the new command system, activation of new army groups and arrival of replacement groups from Manchuria. In late March, the Army General Staff circulated among the armies its basic plan for defense of the Homeland. This was the first step in the "KETSU-GO" operational preparations.
At the same time, the Army General Staff studied plans to revise direction of operations on the Continent in keeping with the new Homeland defense program. It was decided to contract the lines in southwestern China and to strengthen defenses in central and northern China, southern Manchuria and Korea in anticipation of future operations by both Soviet and Allied forces. The Kwantung
Army, the China, Expeditionary Army and Korea Army were given the necessary orders and directives to that effect.
Air Operations and Enemy Bombing of the Homeland
On 6 February 1945, instructions (based on a tentative agreement with the Navy) were delivered to all armies concerning the
general air operation policies against enemy forces invading the East China Sea.49 The main points of these instructions were:
1. The commanders of the Tenth Area Army, China Expeditionary Army, General Defense Command, Southern Army and Kwantung Army will conduct air operations in accordance with the Army-Navy Central Agreement Regarding Air Operations for the first half of 1945 and the Outline of the Direction of the Army Air Operations.
2. The CinC of Defense will be responsible for all air operations over Okinawa and all areas north of this island.
The tentative Army-Navy Central Agreement Regarding Air Operations for the first half of 1945 established the policy for attacking and destroying enemy advances into the East China Sea. Combined Army and Navy Air Forces were to be used. Inner defense positions of Japan were to be strengthened. Special attack forces, trained in suicide tactics, were to be built up.
In the event of air operations in the area around the East China Sea (Formosa, Nansei Islands, southeast China, Kyushu and Korea) both Army and Navy Air Forces were to be deployed in the area immediately to attack the advancing enemy. Main targets for the Navy Air Force would be the enemy task force, while the Army Air Force would first attack transport ships. The Army Air Force, however, was to assist the Navy in its mission as much as circumstances permitted.
In the area along the south China coast, generally the Army Air Force would be responsible for attacking the invading enemy. Air units already stationed in the area would make the initial attack with, when possible, reinforcements being sent to the area. The Navy Air Force would assist in these operations whenever possible.
In the vicinity of Iwo Jima and the Ogasawara Islands, responsibility for the defense of the area would be shared equally by the Army and Navy Air Forces. Both would support the operations of the garrison forces stationed in this area. Future air operations in the Philippines area would be waged by the air forces already stationed in the Philippines as well as those stationed on Formosa. In the Indian Ocean area, the air units already stationed in that area would endeavor to delay any attempted enemy invasion. The present disposition would be maintained in the northeastern
Area. On the China continent, the present minimum strength was all that was available to wage air operations on the western front. In Manchuria, defensive measures were planned against an anticipated offensive by the Soviets. No specific units, however, had been allocated for this purpose.
As over-all air defense planning called for important sectors in both Japan and Manchuria to be protected strongly against enemy air attacks, emphasis was placed on continuing attacks against enemy air bases to put them out of action. In addition, every effort was to be made to build up sufficient reserve air strength through an intensive training program to increase the fighting ability of the service.
Both Army and Navy were instructed to indoctrinate their men in the spirit of suicide attacks. Special attack units were to be increased. At the same time, supporting units were to be developed to enable the special attack units to perform their missions to the fullest extent.
Generally, air battles over Japan or the East China Sea were to be the responsibility equally of the Army and Navy Air Forces. Command posts for the commanders of each service were to be in the same locality in order to insure close liaison. Army and Navy Air Force commanders, therefore, were ordered to confer immediately to decide upon a suitable place from which to conduct their combined actions. Battle fronts for which the Army and Navy were to be responsible remained as before.
An outline of the plan 1b shown on Charts Nos. 14 and 15. The Outline of Directions for Army Air Operations established a policy that, in order to meet any enemy advance toward the East China Sea area, preparations for air operations in that area would be completed by the end of March. Air operations were designated the "TEN-GO" Operations. Their main objective was to destroy enemy convoys. This was to be accomplished by the attack force and direct escort fighter force waiting until their full strength could be launched in an effective attack after the enemy convoys were well within range. Although desirable, aerial support of land operations and similar actions was to be kept to a minimum. This was important in consideration of the degree of training of the Air Forces (especially air crewmen), condition and efficiency of equipment, reserve supplies and critical shortage of fuel.
Two precautionary measures were emphasized particularly. They were:
1. Although tactically it might be desirable to send out fighters to meet enemy fighters during enemy air raids over important areas, unless there was a decided advantage and success was assured, or it was considered absolutely necessary, this would not be done,
2. Other than under very special circumstances, the air forces would not be given the mission of attempting to overcome enemy air bases.
Chart No. 14
Estimated Army Air Strength, End of March 1945
Location Unit Strength Assigned Operational Area Assigned Main Targets Fighters Bombers Reconnaissance Special Attack Japan 6th Air Army 90 90 300 Nansei Islands Transports 60 30 20 100 Sea & Land Air Bases 400 45 Aircraft China 5th Air Army 75 50 50 Formosa Transports 30 70 16 150 China Hainan, French Indo-China 3d Air Army 25 15 Formosa Formosa 8th Air Div. 120 60 10 250 Nansei Islands
Chart No. 15
Estimated Naval Air Strength, End of April 1945
Location Unit Strength Assigned Operational Area Fighters Bombers Reconnaissance Japan Third Air Fleet 340 220 20 Nansei Islands Fifth Air Fleet 200 310 10 Tenth Air Fleet Combat planes
Formosa First Air Fleet 40 40 5 Japan Homeland Air Defense Force 160 Homeland Surface Escort Force 150 Southwestern Pacific 50 Southwestern Pacific East China Sea 150 East China Sea Remarks: a. A part of the Third Air Fleet (40 fighters and 30 bombers) was to operate in the vicinity of Iwo Jima and Ogasawara Islands.
b. The Tenth Air Fleet was a reserve force. Its planes, both combat and training, were to be used as special attack planes.
To assist the Navy Air Force in striking enemy task forces, the CinC of Defense was to use all special attack forces stationed in Japan, with a sufficient fighter force assigned as escort, when the enemy attacked the Homeland. If enemy task forces approached the Nansei Islands area, the commander was to dispatch part of his special attack forces, together with the necessary escort fighter force, at an opportune time which would, in cooperation with the Navy, destroy the enemy. In a similar manner, the Tenth Area Army, China Expeditionary Army and the Southern Army commanders, at an opportune time, would commit part of their special attack forces with the necessary escort fighter forces, to defeat the enemy task forces.
All air base installations were to be strengthened immediately so that, even when subjected to heavy enemy bombings, they could continue to function. These bases were to be strongly guarded by land forces and held firmly as long as possible.
Orders stated that in the event of the enemy approaching the Nansei Islands area, counter air operations were to be equally the responsibility of the General Defense Command (6th Air Army) and the Tenth Area Army (8th Air Division).
To effect a new alignment of air forces for operations around the Homeland during January and February, air force personnel was transferred from the Southern Area sectors where the situation had deteriorated to a such degree that air support could no longer help them. The major transfers were:
The 2d Air Division, in January, transferred the 7th Air Brigade Headquarters, 62d Air Regiment (heavy bombers) and the 45th Air Regiment (assault planes), and, in February, the 66th Air Brigade Headquarters, 65th Air Regiment (assault planes), 66th Air Regiment (assault planes), 27th Air Regiment (assault planes) and the 2d Air Regiment (Headquarters Reconnaissance) to Japan.
The 7th Air Division, in January, transferred the 3d Air Brigade Headquarters and the 24th Air Regiment (fighters) to China, and the 9th Air Brigade Headquarters to Formosa. In February, it transferred the 75th Air Regiment (fighters) to China and the 20th Independent Air Unit (heavy bombers) to Japan.
The 9th Air Division, in February, transferred the 31st Independent Air Squadron (heavy bombers) to Japan.
The Southern Army, in February, transferred the Transport Brigade of the 1st Raiding Group and the 30th Fighter Group (fighters) to Japan.
The 4th Air Army had suffered severe casualties in the Philippines. In late February, therefore, orders were issued inactivating the headquarters. The 2d and 7th Air Divisions, together with the 10th Independent Air Brigade and other miscellaneous units, were placed under the command of the 3d Air Army, while the 4th Air Division, the 1st Raiding Group and various service units were assigned to the Fourteenth Area Army as ground personnel.
In Japan, the 30th Fighter Group was reorganized to include two fighter regiments and one heavy bomber regiment and assigned the mission of attacking enemy task forces operating in the vicinity of Japan.
The loss of the Philippines and the advance of the Allies to Okinawa almost completely cut communications with the Southern Area and made it impossible to send planes to that area. Under these circumstances, the Southern Army was forced to conduct prolonged delaying actions with whatever fighting strength it already had available.
Prom January 1945 onward, the enemy air force used carrier-borne planes to raid the eastern district of Japan, always with increasing intensity. On 16 February, the Kanto district was attacked by carrier-borne planes which flew approximately 1,200 sorties. There was no early warning of this attack and, as the planes flew at low altitude, radar of the frontal screen type failed to detect them. In consequence, it was not until reports began to pour in from the coastal observation posts that Imperial General Headquarters had any idea that an enemy air attack was imminent. In spite of rough weather, enemy planes continued through that day and the following day (17th) to attack airfields all over the Kanto district. On the night of 9 March, some 110 B29's took part in a bombing raid over Tokyo, dropping a large number of incendiary bombs and inflicting heavy casualties and much damage. Especially heavy raids were experienced on 18 and 19 March and again on 28 and 29 March in the northern part of Kyushu. After mid-March, air attacks were made against Kyushu, Shikoku and Kinki districts almost daily.
During March, most attacks seemed to be aimed against airfields and harbor installations in support of the enemy's Okinawa Operation, while during the first half of April, the main targets of enemy bombings were the munition industries and aircraft plants located in Kanto, Shizuoka and Nagoya areas. Toward the end of April, attacks were directed mainly against air bases on Kyushu.
About mid-April, approximately 100 small enemy planes began operations from bases on Iwo Jima.
In April, the Air General Army was established and assumed responsibility for directing air defense. In order to facilitate the protection of vital sections and important installations in Japan, however, air units with specific air defense missions were created and placed under the command of the First and Second General Army commanders.
In May, B29's began incendiary bombings of such cities as Tokyo, Yokohama, Shizuoka, Hamamatsu and Nagoya. These raids all inflicted heavy casualties and tremendous damage.
Part 2 Preparations for "KETSU-GO" Operation (April - August 1945)
Operational Preparations Resulting from Situation Estimate
By April 1945 it appeared that nothing could stop the victorious thrust of the Allies in the Pacific or on the Continent and that an attack on Japan was inevitable. On all fronts Japanese troops were retreating, resources and production were strained to the utmost, transportation and communication facilities had been badly disrupted by air raids and defense preparations were far from complete. The Army General Staff ordered a careful study to be made of the high command system and its adaptation to conducting decisive battles on the Homeland and, on the basis of reports submitted, an operational plan, based on the "Outline of the Imperial Army-Navy Operational Plan" of 20 January 1944-5, was completed about mid-March. This was known as the "Outline of Preparations for the KETSU-GO Operation." On 20 March, in an effort to speed up preparations on the Homeland, the Army General Staff called together the chiefs of staffs and staff officers of the various Area Armies and informally showed them this outline. At the same time, war games were undertaken in order to more clearly demonstrate the new strategy.
There was every indication that, within a short time, the United States forces would attempt a landing on Japan itself, in order to achieve a final victory. It was estimated that, in order to advance their sea and air bases to support the final blow against
Japan, following the Okinawa Campaign the enemy would probably first carry out landings on the coast of China, in the Korean Channel and on the islands in the vicinity of the Homeland. This attempt would probably be made in the summer, while the invasion of the Homeland itself appeared to be set for sometime during or after the fall.
Imperial General Headquarters felt sure that, prior to any invasion operation, Japan would be subjected to massive air raids in order to cripple the defenses and destroy the morale of the people. Although it appeared that the final battle would be fought in the Kanto district, it was thought probable that the initial invasion would be made on Kyushu.
In addition, it was feared that the Soviets would take advantage of the situation to extend their holdings in east Asia. In fact, intelligence reports stated that they had already begun to move their forces into position and that, after the summer, they would be ready to take the offensive any time they thought fit.
In China, the Chungking Army had received considerable support from the Allies and it was anticipated, that, in the fall or winter, this army would launch offensives on all fronts.
In addition, the Yenan (Red Chinese) Army, by accepting assistance from both the United States and the Soviet Union (particularly the Soviet Union) was steadily building its strength and increasing its counteroffensives.
As it was evident that it would be necessary to revise the high command structure, on 8 April, orders were issued, to be effective of the 15th, activating the First General Army and the Second General Army in addition to the Air General Army. The order of battle published for the First General Army placed under its command the Eleventh, Twelfth and Thirteenth Area Armies and ordered it to defend the Northeastern, Eastern and Fast Coast Military Districts. The Second General Army was to command the Fifteenth and Sixteenth Area Armies and to defend the Central and Western Military Districts. The Fifth Area Army, under the direct command of Imperial General Headquarters, was to defend the Northern Military District, while the Seventeenth Area Army, under the direct command of Imperial General Headquarters, was responsible for the defense of Korea. The Air General Army was charged with the responsibility of coordinating the air defense of Japan, the purpose being to provide a single headquarters through which the requirements of the ground forces and the Navy could be coordinated and expedited. As in the case of the formation of the First and Second General Armies, the Air General Army was to organize its headquarters and build up slowly, taking over the air units gradually until it was entirely operational, at which time it was to direct all the air power of Japan.
The revised system of high command for Japan and the neighboring areas is shown on Chart No. 16.
Chart No. 16
Revised System of High Command
With the activation of the First and Second General Armies, directly responsible to the Chief of the Army General Staff, the General Defense Command, no longer necessary, was inactivated.
By Imperial Headquarters Army Order No. 1299 each General Army commander was ordered to destroy the enemy invading strategic areas of the Homeland. To fulfill this duty, he received the following instructions:
1. War preparations, stressing the Kanto and Kyushu areas, will be intensified. Decisive battles will be waged against the United States forces when they attempt to invade Japan.
2. Strategic areas and important installations in the Homeland will be protected from enemy air attacks and, in cooperation with the Navy, sea traffic will be protected and the straits will be defended.
3. The Tsugaru Straits will form the operational boundary between the First General Army and the Fifth Area Army; the Suzuka Mountain Range between the First and Second General Armies; Lat. 30°10'N between the Second General Army and the Tenth Area Army and the Korea Straits between the Second General Army and the Seventeenth Area Army.
The basic principles to be followed by the Air General Army commander in carrying out his mission were:
1. The enemy approaching to attack strategic areas of the Homeland, especially the Kanto and Kyushu areas, will be destroyed at sea.
2. All Allied movements will be reconnoitered and every opportunity taken to intercept enemy planes coming in to attack Japan. Enemy air bases will be attacked and enemy task forces neutralized.
Lines of Communications (Logistical Support) Preparations
The whole country was to mobilize for war immediately and to develop its war potential to the utmost. Supply preparations in the rear areas were to be completed roughly by the end of June and fully by the end of October 1945. Priority, however, was to be given to the important Kanto, Kyushu and Shikoku areas, where preparations were to be completed by the middle of the year. In addition to purely strategic preparations, civil defense forces were to be placed in battle readiness and industrial activities stepped up to full capacity. All avenues that might help the armies in their final struggle were to be explored. Particular emphasis was placed on training, construction of fortifications, general dispersion of war materials, speeding up of production of priority war matériel and procurement of provisions.
The Army, acting as a core force, was to regiment the entire national strength. As concentration of fighting power in Japan was to be accomplished by mid-1945, war matériel production was to be pushed to the fullest extent during the first half of the year. Special efforts were to be directed toward withdrawing as large a fighting force as possible from the Continent to the Homeland.
The principal aims of the Air Force lines of communications preparations were the strengthening of protective installations for planes, stockpiling of bombs for special attack planes, establishment of a complete network of signal communications for transmitting
orders and intelligence reports and the dispersal of aviation fuel dumps. The deadline for the accomplishment of these preparations was June 1945.
The Army was to assume responsibility for fuel production as well as for increased food production. Wherever possible, liberal assistance was to be given civilian industries dealing in fuel and food production. In view of increasing hazards in land and sea transportation, each Army district was to establish a system of self-sufficiency whereby it could conduct operations without assistance from outside agencies. Particular stress was placed on achieving self-sufficiency in food supply, repair of equipment and production of fuel, weapons and other implements of war.
In all preparations for the "KETSU-GO" Operation, the Army was instructed to closely coordinate all activities with the Navy. Transportation
Transportation formed one of the cornerstones upon which much of the success of the "KETSU-GO" Operation depended. Therefore, all important facilities in the hands of the Transportation and Communication Ministry, as well as those of the Army and Navy, were to be unified under a strong centralized control in order to exploit their full potential and to facilitate the completion of "KETSU-GO" operational preparations by the middle of the year. Even after the battle for the Homeland was begun, every effort was to be exerted
to preserve at least sufficient transportation power to take care of troop movements, concentration and replenishment of munitions and activities relevant to the maintenance of the well being of the population as a whole. At this time, all means of transport (both military and civilian) would be controlled and operated systematically.
During the "KETSU-GO" Operation the Army General Staff would exercise ultimate control over railroads, with railway units assuming responsibility for all military railway duties. Initially, however, administration and operation of the railways would be the responsibility of the Ministry of Transportation and Communications, with the Army cooperating in every way possible.
A flexible system of command was to be developed to cover any critical situation which might develop. The Army was to be prepared to take over all railway administrative work if circumstances demanded it.
Since shipping transportation could be the deciding factor in the success or failure of the "KETSU-GO" Operation and the ultimate fate of the Empire, great effort was to be exerted to strengthen the protection of vessels and harbor installations against bombing and to assure efficient, fast-moving debarkation operations. In addition, attempts were to be made to establish a traffic zone in the Japan Sea which would be secure against enemy intercepting maneuvers.
Communication System Preparations
In order to assure the smooth working of communications even under the most rigorous bombing attacks, all means of communication were to be consolidated systematically into one comprehensive system, nerve centers commanding operational key junctions were to be rearranged and strongly protected.
In arranging and operating the communications network, priority was to be given to faster transmission of all intelligence reports required by the Air Force in conducting its operations and to Imperial General Headquarters operational orders.
In operating government or civilian communication services, first priority was to be given to military operations but those official communications necessary to the prosecution of national administration were to be given due regard. These two types of communication were to be so regulated that one would not necessarily preclude the other.
All communications equipment and installations (Army, official and civilian) were to be directed toward the serving of the strategic purposes of the "KETSU-GO" Operation. To meet strategic exigencies, the vigorous application of all types of improvisation in communication devices was to be encouraged.
Code personnel already in service with signal units were to exert every effort to increase their proficiency and a short-term intensive program for the training of additional signal and code personnel was to be begun immediately.
Strong measures were to be initiated to guard electric power plants.
In the initial stages of the decisive battle, movement of ground forces was to be according to the provisional plan already described.
Concentration of forces would then be directed according to the development of the situation. Should the direction of the invasion be evident in advance and a swift shift in basic battle positions be necessary, movement of troops would be made according to the established basic plan. Should a revision in this disposition be required, however, Imperial General Headquarters would issue the necessary orders immediately. Each General Army was instructed to set up its plan of assembly, in accordance with a pattern indicated on Chart No. 17 by the end of August, and to strive to accomplish all necessary preparations by the end of September. All movement of troops was planned to be accomplished primarily by foot in anticipation of the transportation system being disrupted during an invasion. If circumstances permitted, however, troops could be moved by train or ship. Army baggage, which the marching troops could not
Chart No. 17
PLAN OF THE ARMY GENERAL STAFF FOR MOVEMENT OF LAND FORCES DURING KETSU-GO OPERATIONS
carry, was authorised to be transported by train or ship. Troop movements were to be executed even under enemy air attacks. Operational routes were to be selected in areas where enemy interference would be relatively slight.
Concentration of troops swiftly and efficiently was the responsibility of the commandant of each operational zone. A certain flexibility was to be maintained in the transfer of troops. Should the enemy attempt to invade an area from which it had been predetermined to transfer the forces to another sector, the original movement plan would be modified and sufficient strength would remain to confront the invading enemy. In an extreme case, the entire transfer would be cancelled.
Army-Navy Strategic Collaboration
In April 1945 a new central agreement between the Army and Navy providing for command relations and division of responsibility in operations in Japan Proper and in the surrounding seas to meet the impending decisive battle was concluded. It established a unified command for ground units (even in naval or guard districts), under the First or Second General Army commanders, while surface and submarine operations were to be commanded by the Commander in Chief of the Combined Fleet. In addition, it stipulated that, in the event of an enemy attack, air defense units, important air force units and base service special attack units were to be placed under the coordinated command of the local Army and Navy commanders.
The Army strongly expressed its desire to assume the unified command of the entire ground operations, even during operational preparations, but the Navy firmly opposed this demand. Finally, an agreement was reached whereby the First and Second General Army commanders could issue orders during operational preparations but only in matters regarding ground defense plans and necessary training.
Since both surface and submarine warfare was to be directed by the Commander in Chief of the Combined Fleet, the following Army fortress units were to be placed under the command of the respective Navy commanders in order to coordinate surface operations: Soya, Tsugaru, Tokyo Bay, Yura and Hoyo Fortress Units; parts of the Shimonoseki, Iki and Pusan Fortress Units and those units charged with covering the entrances to Ise and Kagoshima Bays.
General Military Preparations and Disposition of Fighting Forces
On 2 April, as part of the Second Army Mobilization Plan, an order was issued to create eight well-equipped divisions, which were to furnish the core of the mobile fighting strength.50 This was followed on 6 April by a further order calling for the mobilizing of six independent tank brigades and five tank regiments. In the meantime, the 11th, 25th and 57th Divisions and the 1st Tank Division arrived in Japan in quick succession from Manchuria.
On 23 May, as part of the Third Army Mobilization Plan, 18 divisions (originally l6 planned) were activated.51 Also activated under this order were 14 mixed brigades, 3 mixed regiments, 3 independent field artillery regiments, 4 independent field artillery battalions, 9 independent mountain artillery regiments, 32 trench mortar battalions, 10 self-propelled gun battalions, 3 field heavy artillery battalions, 3 independent mortar battalions, 4 independent heavy artillery battalions and 30 independent engineer battalions.
By this time Iwo Jima had been lost and the defense forces on Okinawa were fighting stubbornly with their backs to the wall. The menace of an enemy invasion of Japan, especially of southern Kyushu, was increasing daily. It was now almost certain that the enemy would attempt to spearhead its attack against Japan during or shortly after the fall of 1945.
Faced with this ominous situation, there was no time to be lost in completing preparations for the "KETSU-GO" Operations. Available national power, however, was pitiably short of requirements. As a result, the government was forced to fall back on further regimenting all manpower, and replenishment of stockpiles of matériel depended on what production could be achieved during the few months left. First priority was given to the replenishment of equipment and supplies for the various Army groups stationed in the Kyushu area, even to the extent of temporarily deferring preparations in
the eastern Japan sectors, as strategically Kyushu was regarded as the most important area.
In addition, some transfers were made of the forces within Japan with the idea of filling gaps in defense preparations. The 77th Division from the northern District and the Headquarters of the 40th Army from Formosa were transferred to Kyushu, while the 147th Division from the Northern District was transferred to the Kanto District.
With the withdrawal of two divisions from its command, the Fifth Area Army was now given a new operational mission commensurate with its reduced strength. On 8 May 1945 an order was issued stating that the Fifth Area Army now had the two-fold mission of frustrating enemy attempts to advance their air and sea bases to the Northern Area and of overcoming their harassing maneuvers in the Japan Sea. The fulfilment of this mission would greatly assist the prosecution of the Homeland battle plan.
To do this, battle preparations were to be completed on Hokkaido and, from here, counterattacks were to be launched to prevent the enemy from advancing their air and sea bases. In addition, the Fifth Area Army was to provide protection for strategic points in the Kuril Islands and southern Karafuto. The Army was to cooperate with the Navy in checking enemy attempts to dominate the Japan Sea by holding firmly strategic points on the coasts of Soya and Tsugaru Straits. Furthermore, in order to operate without outside
help, the Fifth Area Army was to set up a system immediately that would make it self-sufficient in provisions, war matériel and fuel.
To prepare for a Soviet attempt to invade Hokkaido or for an Allied attempt to come down from the north, the Fifth Area Army was to strengthen the strategic zones in northern Japan and to hold the strategic areas in the Kuril Islands and Soya Strait at all costs.
Situation in Korea
Since April there had been indications that the Soviet Union was gradually transporting troops from the European Theater to the East and it was becoming increasingly clear that by timing their actions with the progress of the Okinawa Campaign, they would eventually attack Japan in or about the summer of 1945.
Toward the end of May, the Army General Staff was convinced of the urgent necessity to strengthen and consolidate defensive preparations against the Soviets la northern Korea and Manchuria. On 30 May 1945, therefore, Army Department Order No. 1339 was issued placing the Korea Army District commander under the direction of the Commander in Chief of the Kwantung Army in regard to preparations for operations against the Soviet union and the united States Army in north Korea.52
The Seventeenth Area Army commander, as operational Army commander, was responsible for operational army missions in south
Korea whereas as Korea Army District commander he was responsible administratively for the whole of Korea.
This situation called for close liaison between the commanders of the Kwantung Army and the Seventeenth Area Army, particularly as the Seventeenth Area Army commander was authorized to use army personnel of the Kwantung Army to assist his civilian staff in carrying out his mission in north Korea. A rider, however, was inserted stating that such army personnel would be used only when such use would not interfere with the execution of the operational mission of the Kwantung Army.
Direction of Operations Against Enemy Invasion of Okinawa
From early January until mid-March, enemy planes continuously attacked Formosa and Okinawa with increasing intensity. It now seemed inevitable that the next move would be against the Nansei Islands. In late March, enemy task forces, operating from their bases in the Marianas and Ulithi, attacked Okinawa, mainly with carrier groups, with the number of sorties estimated at between 500 and 700 daily. Finally, the climax was reached on 25 March when United States forces landed on Kerama Island.
Although it was now all too clear that the United States forces intended to land on Okinawa, the Japanese air units were in no condition to prevent them. The 5th Air Fleet, which was to have played a leading part in this operation, had lost its fighting power in the air operation off Kyushu, and neither the 3d or 10th Air Fleets had
yet advanced to Kyushu. Furthermore, the transfer of the 6th Air Army's special attack planes to Kyushu mas not being completed as swiftly as planned. In order to assure complete coordination of the Army and Navy Air Forces, on 19 March an order was issued placing the 6th Air Army under the command of the Commander in Chief of the Combined Fleet for all operations in the Nansei Islands area. The 12th Air Group Headquarters, which was to have directed the attack, bad not had time to replenish the losses suffered during the Philippines Campaign, nor had the scheduled deployment of twelve special attack units to the hansel Islands been started.
In spite of all this, the Commander in Chief of the Combined Fleet ordered "TEN-GO" Operation to commence on 26 March.53 The 3d and 10th Air Fleets were placed under the operational command of the 5th Air Fleet and ordered to move to Kyushu immediately. On 31 March, both Air Fleets finally completed deployment of their available strength to Kyushu.
The commander of the 6th Air Army received word on 28 March that an enemy convoy had been sighted and issued the order to attack. The strength available for this attack, however, numbered only 10 heavy bombers and about 15 assault planes. Thus, because they were unprepared operationally, the air units lost the opportunity to launch "TEN-GO" Operation effectively.
In the meantime, from 26 March, the 8th Air Division on Formosa had attacked enemy vessels around Kerama on a number of occasions. It reported that it had employed 45 special attack planes and 17 bombers and, by the 31st, had damaged or sunk 31 vessels.
The United States task force again raided the Kyushu area on 28 and 29 March but the 5th Air Fleet lacked the fighting power to carry out effective counterattacks.
On 1 April, United States Marines and Army troops landed on Okinawa and, by evening, had occupied the airfields on the north side as well as those situated in the middle of the island.54
For the first three days of April, the 8th Air Division, with ho special attack planes and 20 guide planes, delivered daring attacks against enemy vessels off Kadena. It reported that it had sunk or damaged about 20 vessels but this had little effect on the overall situation.
The Army General Staff, dissatisfied with the manner in which the 32d Army was conducting the campaign, issued orders to the effect that the 32d Army would immediately begin aggressive offensive operations and deny the enemy use of the airfields. These orders were transmitted through the Tenth Area Army commander. The 32d
Army, therefore, prepared to abandon its policy of delaying tactics and, on 8 April, to launch a general attack to win back the enemy-held airfields. While preparing for the attack, word was received that a United States convoy had been sighted off Machinato Port on 7 April and, fearing a flanking attack, the 32d Army decided to suspend its general attack.
Meanwhile, the Combined Fleet, together with the 6th Air Army, as part of a preliminary to the expected ground attack by the 32d Army, from 6 April, carried out continual naval and air bombing attacks. By the 9th, it appeared as though they had successfully reduced the number of enemy ships around Okinawa and that the enemy ground attacks were weakening. Taking advantage of this situation, on the night of the 12th, the 32d Army opened an attack, but from the beginning it proved unsuccessful and, by morning, the entire plan was abandoned. The 32d Army then fell back on its original plan of delaying actions.
On 19 April, the enemy launched a general attack against the 32d Army's fortified positions. The Japanese troops fought desperately but gradually were forced to give ground until, by the end of the month, they were driven back to the last line of entrenchments.
As the Army General Staff and Tenth Area Army commander continued to order the 32d Army commander to take the offensive, on 29 April, the Army commander decided to launch a final attack with his
full strength on 4 May. By the following day, however, checked by the bombing and bombardment of the enemy, the attack was discontinued and the 32d Army began again to conduct delaying tactics from its positions. During this offensive the Japanese 24th Division lost about two-thirds of its combat strength and the other units also suffered heavy casualties. In addition, most of the ammunition was now spent.
In spite of all this, the Navy still desired to attempt to recapture Okinawa.
On 8 April, when the Air General Army was activated, the 6th Air Army had been placed in the organizational chain of command of the Air General Army but had remained under the tactical command of the Commander in Chief of the Combined Fleet. Toward the end of Nay, Admiral Toyoda, Commander in Chief of the Combined Fleet, became the Chief of the Naval General Staff and was succeeded as Commander in Chief of the Combined Fleet by Vice Admiral Ozawa. As Admiral Ozawa was Junior to Lt. Gen. Sugahara, commander of the 6th Air Army, on 28 May, the 6th Air Army was detached from the Combined Fleet and again placed under the command of the Air General Army.
At the close of May, it was evident that the days of desperate and futile fighting against the overwhelmingly superior strength of the United States forces were about to come to an end for the defenders of Okinawa. The Army General Staff, therefore, regarded it
as essential that the entire Army be placed in position to undertake the "KETSU-GO" Operation. It was at this time that the 6th Air Army was removed from the tactical command of the Commander in Chief of the Combined Fleet.
With the fast deteriorating situation, it was necessary to modify the operational plan of the Army Air Force. At the end of May, the Army General Staff offered four alternative operational plans, according to how the situation developed.
1. Should the Okinawa Operations continue, the main force of the 8th Air Division (Formosa) and part of the 6th Air Army (Kyushu) would continue air operations against Okinawa.
2. In the event the enemy landed on Amami Oshima, the main force of the 8th Air Division (Formosa) and part of the 6th Air Army (Kyushu) would be used against this force.
3. In the event the enemy landed on Sakijima Islands (Miyako and Ishigaki), the total strength of the 8th Air Division (Formosa) would be used against the enemy.
4. In the event the enemy landed in the China Triangular Zone (around Shanghai), the main force of the 8th Air Division (Formosa) and the 13th Air Division (China) would attack. In this case, the 5th Air Army (southern Manchuria and Korea) would send 100 special attack planes to support the 13th Air Division's operation.
Strength of the Army Air Forces and location of the units at this time are shown on Chart No. 18.
Chart No. 18
STRENGTH OF ARMY AIR FORCE, END OF MAY 1945
Plans for Operations and Reorganization of Forces in the China Theater
After the successful conclusion of the Hunan-Kwangsi Operation the Commander in Chief of the China Expeditionary Army strongly recommended that he be allowed to deal a decisive blow to the Chungking forces before they could rally and carry out a counterattack, about mid-1945, by making a deep thrust into Kweichow Province. However, with the situation in the Pacific rapidly growing worse and the probability of both Japan and China being attacked from the sea daily increasing, Imperial General Headquarters felt that only small-scale raids into the interior of China should be undertaken and that emphasis should be placed on strengthening the Japanese forces in central and south China, particularly in the key sector in the lower reaches of the Yangtze River. Furthermore, with the Allied successes in Europe and in the Pacific, Imperial General Headquarters was of the opinion that the will of the Chungking Government to continue the fight would be strengthened and that it would continue to resist.
On 22 January 1945, the new mission of the China Expeditionary Army was issued exhorting its commander to put forth every effort to check the United States forces invasion of China and destroy the Chungking regime by securing the vital areas of China. Strategic areas of China were to be strengthened as quickly as possible and the national defense zone, with Japan as its center, was to be secured by defeating the enemy attempting to invade from the east and
west. This was to be achieved by strengthening the defenses of central and south China, especially along the lower reaches of the Yangtze River. Strong pressure was to be applied in order to destroy the Chungking regime's fighting potential and to combat the political influence of the United States. In addition, every effort was to be exerted to check enemy air activities in China.
The Army was ordered to establish operational bases and stabilize the occupied areas, particularly in north China and the lower reaches of the Yangtze River in order to secure national defense resources.
All ground operations, with the exception of minor attacks by raiding parties, west of Vest Sunit to Pailingmiao, along the Huang Ho and western border of Shansi Province, through Laohokou, Ichang, Shoushan, Ipehhsien and Liuchowhsien, were to be carried out only under special definite orders.
In addition, the China Expeditionary Army commander was to cooperate as far as possible in air operations in Formosa and the Nansei Islands. He was to maintain communications with the Southern Area and to cooperate with the Navy in escorting sea traffic.
When considered desirable, forces under the command of the commander of the China Expeditionary Army could operate outside their area of responsibility with the knowledge and consent of the commanders of the areas entered.
On the basis of the new operational plan in China, an Army-Navy Central Agreement was published with the following objectives:
To strengthen immediately war preparations in the southeastern coastal region of China and to concentrate the necessary military strength at a proper time to destroy United States forces attempting to invade China. To divert fighting strength mainly to the Kwantung area.
To strengthen war preparations in the strategic area of the lower reaches of the Yangtze River, especially the Shanghai area by early summer of 1945. To divert as many troops as possible to this area in the event of an enemy landing and to carry out a decisive battle to destroy the enemy.
Local Army and Navy units on Hainan Island were to be used to secure important ports and airfields on the island and, for as long as possible, to deny the enemy use of these facilities.
In order to execute this operational plan, the China Expeditionary Army planned to carry out the following troop movements: To reinforce the 23d Army with an additional two divisions. To dispatch one independent mixed brigade to Hainan Island where it was to come under the command of the Naval Guard District commander. To strengthen the 13th Army by diverting seven divisions and one tank division from north China and one division from the Wuchang-Hankou area to Shanghai.
In addition, one division was transferred from Nanching to Shanghai. Under a separate Imperial General Headquarters order, the 37th Division and later the 22d Division were dispatched from
the Sixth Area Army to French Indo-China. Furthermore, orders were issued for the reorganization of replacement units in China and the organization of 4 divisions, 12 mixed brigades and 13 independent guard units from the remaining replacement personnel. The organization or reorganization of most of these units was completed between the end of January and March, while the remainder was completed by the end of April. Three newly established divisions were used reinforce the defenses along the coast of China while the remainder were used chiefly for guard purposes in the interior.
Prior to this, on 26 January, the Sixth Army Headquarters had been transferred from Manchuria to the lower reaches of the Yangtze River to strengthen this area. There it came under the command of the 13th Army commander.
In June, the 34th Army Headquarters was moved to north Korea while its forces remained in the Wuchang-Hankou area under the direct command of the Sixth Area Army.
In addition to reinforcing ground military preparations, air strength was reorganized. In March, the 13th Air Division was activated and placed under the command of the 5th Air Army. One air brigade headquarters and three air regiments (which had been transferred in April 1944 from Manchuria to the direct command of the China Expeditionary Army) also were placed under the command of the 5th Air Army commander.
Operational Preparations Against the Soviet Union
In January 1945, operational preparations against probable American landings along the coast of China were started in the lower reaches of the Yangtze River and at Canton. In April, after United States troops landed on Okinawa, the Soviets abrogated the Soviet-Japanese Neutrality Pact. This was regarded as a strong indication that they would soon enter the war against Japan. In mid-April, therefore, Imperial General Headquarters ordered the concentration of four divisions in the vital areas in north and central China and directed the China Expeditionary Army to assemble the 3d, 13th, 27th and 34th Divisions in central China for that purpose. By mid-May, when the situation on Okinawa appeared hopeless, Imperial General Headquarters ordered the evacuation of the areas along the Hunan-Kwangsi and Canton-Hankou railway lines in the provinces of Hunan, Kwangsi and Kiangsi, so as to strengthen strategic positions in north and central China.
Germany's capitulation in May made even more certain that the Soviet Union would soon move against Japan. Although it was at first planned to use the 3d, 13th, 27th and 34th Divisions in Manchuria, later it was felt that it would take too long to move them into position. The 39th, 59th, 63d and 117th Divisions, therefore, were placed under the command of the Kwantung Army and the 5th Air Army was placed in the order of battle of the Air General Army. The Headquarters of the 5th Air Army was set up in Seoul and the balance of its forces moved into Korea and north China.
Imperial General Headquarters estimated that the main and immediate objectives of the Soviet Union would be Manchuria and China but that it would then attempt to expand into the southern countries, which were rich in natural resources. It was estimated that the Soviet Union would enter the war in summer or fall - about the same time as it was Judged the Allies would attempt to invade Japan, south Korea and north-central China. Further weight was added to this estimate by the fact that climatic conditions in Manchuria would make it advisable to attain their objective before December when the really cold weather would begin.
Although estimates of the number of Soviet troops to be employed and the time it would take for their transfer to the East differed, it was believed that it would take at least four or five months to transport approximately 40 infantry divisions with supporting tanks and planes, together with the necessary supplies and equipment, to the front. As the Soviet Union had begun to transport a force, believed to be of this size, late in February 1945, it was estimated that they would be concentrated in strategic areas in east Russia by June or July. Some of the war supplies had already been accumulated in east Russia and, as troop movements could be speeded up, even though it might take one or two more months to prepare for the attack, it was expected that they would be ready to go into action not later than September.
In January 1945, the Kwantung Army had drawn up an operational plan stating that its basic policy was to destroy the enemy invaders near the border area (a vast area outside the line formed by the mountain range east of north Korea, the mountain range west of Mutanchiang, the Lesser Khingan Range, the Greater Khingan Range and the Ssupingchieh-Chichihaerh Railway) by utilizing the terrain and defense positions. It would Repulse, check or obstruct a further enemy advance by taking advantage of the vast expanse of Manchuria and Korea in an effort to hold out as long as possible. Even under the worst possible circumstances, the mountainous area, extending from the southern sector of Manchuria to north Korea was to be held firmly in order to facilitate the overall prosecution of the war.
It was necessary to dispose, in advance, men and matériel throughout Manchuria and in north Korea and to construct fortifications in all areas of operations but the main portion of the combat strength was to be concentrated along the Manchuria-Korea border where determined holding operations were to be conducted. This meant that the Kwantung Army had to push operational preparations on an entirely new concept. It was faced with a formidable task. Central, south and southwest Manchuria were almost entirely defenseless against Soviet invasion and everything demanded a fresh start. Although Soviet moves made it imperative that preparations be completed as quickly as possible, the available supply of material needed to strengthen the areas was far from sufficient.
By the close of 1944 most of the better trained divisions of the Kwantung Army had been diverted to the Pacific, China, Formosa and the Nansei Islands areas and forces in Manchuria were about one-half the strength in that area at the end of 1943.55 In particular, air, signal and engineer units had been affected. In addition, there was a critical shortage of officers, particularly junior officers, in the Kwantung Army, as many had been withdrawn to Japan to strengthen the defenses of the Homeland. Equipment and supplies for units were low and in poor condition. In short, the Kwantung Army was pitiably weak in both men and matériel.
On 16 January 1945, the Army General Staff had ordered the emergency mobilization of eight divisions (121st through 128th) and four mixed brigades (77th through 80th) to be organized from the 3d Cavalry Brigade and some border garrison units but, as mentioned previously, this was an artificial increase in the defense organization of the northern boundary. In March, four picked divisions (11th, 25th, 57th and 1st Tank) were redeployed to Japan and three divisions (111th, 120th and 121st) to Korea, as well as one-third of the ammunition and some officers being transferred to Japan.
Earlier, the Kwantung Army, feeling it necessary to have an army headquarters exclusively in charge of the western front of Manchuria
and another in charge of inner Manchuria and the redoubt area, had asked Imperial General Headquarters to create two army headquarters. Nov, with the Soviet notification of the abrogation of the Soviet-Japanese Neutrality Pact, the Kwantung Army decided to complete disposition of units on its own initiative and, about mid-May, issued orders transferring the Third Area Army from Chichihaerh to Mukden, the headquarters of the Kwantung Defense Army from Mukden to Liaoyuan, the headquarters of the 4th Army from Sunwu to Chichihaerh and the 125th Division from the vicinity of Heiho to the vicinity of Tunghua. In addition, in an effort to bolster the Kwantung Army strength, the 34th Army Headquarters (from Hankou) and four divisions (from China) were transferred to Manchuria. A special construction brigade was activated to take care of construction of fortifications and roads and the demolition of airfields. At the same time studies were undertaken to determine if, by mobilizing the civilians in Manchuria, the strength of the Kwantung Army could be increased from 450,000 to 900,000 men.
In late May, with the outcome of the battle for Okinawa all but decided, the build-up of Soviet forces in the Far East was rapidly reaching its climax. On 30 May 1945, therefore, Imperial General Headquarters reorganized the Kwantung Army according to a new order of battle and issued the following order:
1. Imperial General Headquarters intends to strengthen preparations for the operations against the United States and the Soviet Union in Korea and Manchuria.
2. The Commander in Chief of the Kwantung Army will fulfil currently assigned duties and take the necessary measures to destroy the invading United States forces, while at the same time stepping up preparations for operations against the Soviet union in north Korea. For this purpose the Commander in Chief of the Kwantung Army will dispose in north Korea the required strength under his overall and tactical command and also direct the commander of the Korea District Army in regard to preparations for operations against the Soviet Union and the United States in north Korea.
On the same day, Imperial General Headquarters ordered the Commander in Chief of the Kwantung Army to conduct preparations for operations against the Soviet Union in accordance with the "Outline of the Operational Plan Against the Soviet Union in Manchuria and Korea."56 At the same time, the commander of the Seventeenth Area Army was ordered to transfer the 79th Division, the 101st Mixed
Regiment and the fortress garrison units at Najin and Yonghung Bay in north Korea to the Kwantung Army while the Commander in Chief of the China Expeditionary Army was ordered to transfer four divisions and other units to Manchuria, and to make necessary preparations for operations against the Soviet Union.
Preparations for the Defense of the Homeland from June 1945
During the Third Stage Mobilization in June the 50th, 54th and 59th Army Headquarters were organized and placed under the command of the Eleventh (Northeast), Thirteenth (East Coast) and Fifteenth (Central) Area Armies respectively. At the same time, the Zentsuji and Hiroshima Military Subdistricts were redesignated the Shikoku and Chugoku Military Districts. These "military districts" served as the administrative headquarters for the operational 55th and 59th Army Headquarters, with the commanders and some of their staff serving in dual capacity as members of both staffs.57
During this final marshalling of Japan's manpower, in addition to the Army Headquarters, eighteen divisions were activated for service in Japan.
On 23 June, in order to improve the defenses of Tokyo, the order of battle of the Tokyo Defense Army was published. At the same time, this army was placed under the command of the Twelfth Area Army. The principal mission of the Defense Army was to strengthen
the defenses of the capital and to protect the Imperial Palace and its environs. This was to be accomplished by the construction of fortifications and the destruction of as large a number of the enemy as possible before they entered the city. It was planned that, with the launching of "KETSU-GO" Operation No. 3, the following units would be placed under the command of the Tokyo Defense Army: two or three field divisions; one regiment of the 1st Antiaircraft Division; one independent tank brigade, two heavy field artillery regiments, one independent field artillery regiment and one independent mountain artillery regiment. These units were all to be drawn from units not already under the command of the First General Army. The Tokyo Defense Army received instructions that facilities and installations, except for those actually required in the defense of the city, were to be removed or destroyed in order to deny their use to the enemy. During operational preparations strongly built underground fighting and storage sites were to be constructed. It was estimated that this operation would continue for one year. Operational supplies and equipment to be shipped in from other areas were to be stored underground. The principal mission of the Imperial Guards Division was the defense of the Imperial Palace. It could be employed in other areas, however, during operational preparations, provided such employment did not interfere with the Division's primary mission. In addition, national volunteer fighting units (under the command of the Tokyo Defense Army commander) were to be employed during the early stages of the operation for the defense of Tokyo.
In January 1945, the enemy had carried out a series of bombing raids directed mainly against the Tokai District and, in February, raids against the Kanto area. In January, the enemy had begun to transfer B29's from the interior of China to the Marianas, and, by March, the sharp increase in the number of raids on the Homeland made it evident that the transfer was well under way. Furthermore, after 9 March, the enemy switched to night raids with large formations and subjected the suburbs of Tokyo to indiscriminate incendiary bombings. Prior to this, their objectives had been military installations, mainly munitions production plants. It was thought that these air attacks directed against the Tokai, Kanto and Kyushu districts during March were aimed at supporting the invasion of Okinawa.
On 28 March, enemy bombers laid mines in the Shimonoseki-Moji area for the first time.
The air defense units fought valiantly but shortage of air strength and inferior equipment made it impossible for them to turn back the enemy bombers flying at high altitudes at night.
The enemy continued to step up their air offensive against Japan until, by June 1945, their land-based air force, which was spreading destruction in Japan, was estimated to be about 2,000 planes, of which 700 were based on Okinawa, 300 on Iwo Jima and 1,000 (mostly B29's) in the Marianas. It was estimated that enemy air strength could be expected to increase as follows:
Type and Number of Aircraft Sea Planes Fighters Light
B24's B29's Total Sep 1945 120 1,500 480 650 1,150 3,900 Dec 1945 120 1,775 830 1,200 1,500 5,425 Mar 1946 120 1,950 1,090 1,400 1,500 6,060
In June, indiscriminate incendiary raids against smaller cities were greatly intensified. Enemy mine-dropping operations against the harbors and straits in the Inland Sea and the Sea of Japan became even more persistent with the result that traffic on the Inland Sea was virtually paralyzed. Moreover, full-scale attacks by land-based air forces from Iwo Jima and Okinawa and large-scale carrier strikes continued until they began to assume the character of strategic bombings as a prelude to landing operations.
Meanwhile, enemy fighters based on Okinawa continued to attack southern Kyushu.
Gravely concerned with the situation, Imperial General Headquarters modified its policy of preserving air strength and decided to carry out interception operations against enemy bombers with its main air strength. Accordingly, the 10th, 11th and 12th Air Divisions, which had been operating under the tactical command of the Commanders in Chief of the First and Second General Armies, were brought completely under the Air General Army on 1 July.
An outline of the directive issued to the Commander in Chief of the Air General Army, who was now responsible for all air defense operations in Japan, was as follows:
1. The main objective of air defense operations conducted by the Commander in Chief of the Air General Army, in cooperation with the Navy, will be the shooting down of hostile aircraft. The procedures to be followed will be:
a. The required air strength will be stationed in important areas in Japan to engage exclusively in air defense, while sufficient strength will be held in reserve as mobile interceptor units. Special efforts will be exerted to shoot down heavy bombers. The air strength to engage exclusively in air defense will be:
Eastern District 4 fighter regiments Tokai and Central District 4 fighter regiments Western District 1 to 3 fighter regiments
These air units may be moved from one district to another as the occasion demands.
b. Should the opportunity seem favorable, even one enemy heavy bomber will be intercepted by the necessary number of fighters and destroyed.
2. Enemy flights composed of fighters alone will not be attacked, except when the situation is especially favorable or out of dire necessity.
In compliance with this directive the Air General Army mapped out a plan, known as the "SEI-GO" Operations whereby it would attack enemy aircraft by the concentrated employment of all Army interceptor fighters available in Japan. The interceptor operations were
not as successful as originally expected, however, owing to the difficulty encountered in concentrating the required strength during enemy bombing raids, while the enemy bombers were escorted during raids by strong land-based fighter units from Iwo Jima, as well as by carrier-borne fighters.
Earlier, the Navy Section had planned an air attack against B29 bases on the Marianas but Misawa, where preparations for the attack were being made, was subjected to carrier strikes on 14 July and the plan to raid air bases in the Marianas had to be abandoned.
In preparation for air operations during the "KETSU-GO" Operation and anticipating that the enemy would invade western Japan, the Army General Staff ordered the speeding up of preparations for air operations in accordance with the "Army-Navy Central Agreement Concerning the KETSU-GO Air Operations" concluded on 13 July. This agreement called for the destruction of United States landing forces and transports prior to their landing. Consequently, the air operation was designed to direct maximum effort against United States convoys carrying landing forces. All planes were to be used for these special attacks, with particular emphasis being placed on operational preparations first on Kyushu and the Korea Straits.
Many discussions were held between the Army and Navy in regard to the objectives of the air units. Traditionally, the Army placed first importance on attacks against enemy transports while the Navy
advocated first the destruction of enemy aircraft carriers. Finally, the Army's stand was accepted and it was agreed that the entire strength of the Army and Navy Air Forces would be concentrated on attacking United States convoys.
On 13 July, Imperial General Headquarters issued orders to the Commander of the Air General Army and the Supreme Naval Commander in regard to the execution of operations in accordance with the agreement, the gist of which was:
The total air strength of the Army and Navy, under a unified command, will annihilate United States forces at sea in the initial stage of their operations to invade the Homeland. Air defense and antisubmarine operations in the Homeland area will be strengthened.
Outline of Direction of Operation:
United States convoys carrying invasion troops will be destroyed mainly by special attack (suicide) tactics.
For this purpose, emphasis will be placed first on the completion of operational preparations in Kyushu, Shikoku and south Korea. Thereafter, operational preparations in other areas, particularly in the Kanto area, will be accelerated.
Reconnaissance will be conducted over enemy invasion bases and base line of operations in order to detect as early as possible any move toward invasion of the Homeland.
Attacks against enemy convoys carrying landing troops will be carried out for approximately ten days. Persistent attacks, day and
night, will be carried out in order to destroy the enemy transports before or immediately after they enter the anchorage.
Every opportunity will be taken to attack enemy task forces and to prevent any effective support of enemy convoys.
Cooperation with land operations will be considered of secondary importance, but if strength permits, elements will attack United States vessels giving supporting fire to landing forces.
The Army will concentrate its air strength under one command and conduct interception operations against the United States air forces attacking the Homeland, particularly large American bombers. The Navy will cooperate in these operations.
The Army and Navy will cooperate in launching surprise attacks against the United States' air bases for large planes, particularly those bases on the Marianas, Iwo Jima and Okinawa.
The Navy will intensify its operations against United States submarines in the Sea of Japan and endeavor to sweep away or check the movements of these submarines.
The Army and Navy will cooperate in endeavoring to frustrate any attempts by the United States Air Forces to blockade Japan with mines.
Disposition and employment of Army and Navy Air Forces based on the above plan are shown on Charts Nos. 19a and 19b.
As a general rule, the Army and Navy were to cooperate in all operations. Top commanders of the Army and Navy Air Forces were to remain at the same location during operations in order to direct close cooperate between the two services.
Chart No. 19a
Disposition and Utilisation Plan of the Air General Army Air General Army 1st Air Army (Mainland East of Suzuka Mts.) Approximately 600 Special Attack Planes 1. Reserve forces of the 6th Air Army for an operation in Kyushu and in Shikoku.
2. Main force for the operation in Kanto.
Approximately 500 miscellaneous planes Concentration of fighters for intercepting enemy bombers attacking the Homeland. 6th Air Army (Mainland West of Suzuka Mts., Shikoku and Kyushu) Approximately 400 miscellaneous planes Approximately 1000 Special Attack Planes Main body of the Air General Army as a nucleus for the operations in Shikoku and Kyushu. 5th Air Army (Main force in Korea and a part in Manchuria and Northern China) Approximately 200 miscellaneous planes 1.For either front line fighting or as a reserve force of the 6th Air Army for an operation in Kyushu and Shikoku.
2. Main force for the operation in Southern Korea.
Approximately 500 Special Attack Planes Note: This plan could be altered to fit the changing situation. 500 to 1,000 additional special attack planes were to be Note: readied during July and August. Miscellaneous planes included fighters, reconnaissance planes, assault planes, and bombers, for orthodox tactical use.
Chart No. 19b
Disposition and Utilization Plan of the Navy Air Forces Combined Fleet 12th Air Fleet (Hokkaido) No planes, only air base units Responsible for the defense of Northeastern Area. 10th Air Fleet (All Mainland) 1,070 planes for attacking task force and landing convoy
Reserve force for the 3d and 5th Air Fleet. 3d Air Fleet (Mainland east of Suzuka Mts.) 1,140 planes for attacking task force and landing convoy
40 reconnaissance planes
1. Main force for the operation in Kanto Area.
2. Reserve for the 5th Air Fleet.
5th Air Fleet (Mainland west of Suzuka Mts., Shikoku and Kyushu) 1,765 planes for attacking task force and landing convoy
100 reconnaissance planes
1. Main force for the operation in Kyushu.
2. Reserve force for the 3d Air Fleet.
4th Fleet (Truk Island) 80 planes for attacking task force Responsible for the defense of South Seas Islands. Note: The number indicates the planes on hand.
Air units were disposed on hidden fields, suicide attack units were equipped and their bases reinforced so that, in spite of the fact that the B29's continued their raids with increasing intensity, the Japanese Air Force might still retain its strength to defend the Homeland. There was little chance of appreciably increasing the air strength, however, as airplane production continued to decrease and stockpiles of fuel were rapidly being depleted with no hope of replenishment.
At the end of June, to facilitate operations on Formosa and the Homeland, the following air units were transferred from the Southern Area to Formosa:
From the direct command of the 3d Air Army (with headquarters at Singapore), 35th Air Brigade Headquarters; 204th Air Regiment (fighters) and the 12th Air Regiment (light bombers).
From the 5th Air Division (with headquarters at Phnom Penh), 50th Air Regiment (fighters) and the 6th Air Regiment (light bombers).
From the 7th Air Division (with headquarters on Java), 13th Air Regiment (fighters) and the 61st Air Regiment (heavy bombers).
From the 9th Air Division (with headquarters at Palembang), 21st Air Regiment (fighters); 24th Air Regiment (fighters); 26th Air Regiment (fighters); 58th Air Regiment (heavy bombers), and the 71st Air Squadron (fighters).
Also in June, the 7th and 98th Air Regiments, formerly under the tactical command of the Navy, were returned to the command of
the 6th Air Army. Operational units of the air training divisions in the Homeland were reorganized and placed under the direct command of the Air General Army.
At the beginning of August, it was planned to redeploy all air units stationed on Formosa to the Homeland, but termination of the war was announced before this could be accomplished.
Situation After the Fall of Okinawa
The main body of the 32d Army was lost on Okinawa and it now appeared as though the Homeland must be the next battlefield. On 20 June, the Army General Staff ordered the Tenth Area Army commander to destroy the enemy attacking Sakijima Islands and Formosa and to harass their air and navy bases in the Nansei Islands. This was designed to aid the general over-all operations. At this time, the operational boundary between the Tenth Area Army and the Second General Army was adjusted to a line between Kagoshima and Okinawa.
Furthermore, the Tenth Area Army commander was ordered to assist the China Expeditionary Army with his air force in operations against the United States and British units in Chekiang and Fukien Provinces. The Takao Naval Guard District commander was placed under the command of the Tenth Area Army commander for these operations. With the concurrence of the other Army commanders, the Tenth Area Army commander could dispatch units to other operational sectors, where they would, if necessary, be placed under the commander of that area.
After the fall of Okinawa, enemy submarines appeared in the Japan Sea and seaplanes began to attack shipping in the Korea Strait and the Japan Sea. Not only did they cause considerable damage to shipping but their presence made the transportation of units and munitions from the Continent to Japan increasingly difficult. In order to facilitate transportation of necessary units and munitions to Japan, the Army and Navy, on 28 June, published a plan to secure the Japan Sea through joint cooperation. All efforts were to be made to transport the maximum amount of essential war matériel in the shortest possible time. Initially, the main effort of escort, antisubmarine and mine sweeping operations was to be directed to the Tsushima Strait. Later it was to shift to the inner Japan Sea. To prevent infiltration of enemy submarines into the Japan Sea and to strengthen protection of shipping, a tight defense and patrol system was to be established in the Tsushima, Soya and Tsugaru Straits. Controls were to be imposed, when necessary, in order to obtain maximum efficiency in navigation and transportation. This was to be a joint operation of Army and Navy forces and close liaison was to be maintained regarding intelligence information. In carrying out the operation (designated "NICHI-GO") every effort was to be made to conserve fuel.
Continental Organization Revisions and Operations
Ever since the Soviet Union had begun to move its troops eastward, units of the Kwantung Army on the Manchukuo-Soviet border had apt a close and constant watch over rail transportation and the movements of Soviet troops in the Soviet territory. After June there was a marked increase in the number of motor vehicles in the area and Soviet troops and matériel were seen to be moving everywhere along the border. Adding considerably to the tension was the movement of Soviet troops in front of Suifenho (Pogranichnaya) near the east Manchukuo-Soviet border, a movement which appeared tantamount to tactical maneuvers.
The Kwantung Army felt that the Soviets would be prepared to launch an offensive by the end of August if the strength to be committed to the operation was to be 40 sniper divisions, or by the end of September if it was to be 50 sniper divisions.
The policy for operations against the Soviet Union, which Japan had adhered to consistently since the Manchurian Incident, had been to destroy Soviet air bases in the Maritime Territory. This policy was based on the concept that, in the event of war between Japan and the Soviet Union, the first requisite for national defense was to protect the Japanese Homeland from Soviet air attacks. The basic strategy for employing the air force as well as the ground forces, therefore, was to carry the offensive into the Maritime Territory from the eastern frontier of Manchuria and destroy Soviet
air bases in that area. This strategy had governed all military preparations of the Japanese Army in Manchuria - the organization and equipment of troops, disposition of forces, construction of defense installations, logistic preparations, construction and maintenance of airfields, railways, roads and communication networks, and military training.
The opening of hostilities in the Pacific had made no basic change in this policy. Imperial General Headquarters, however, had instructed the Kwantung Army to avoid the outbreak of war with the Soviet Union, if at all possible.
The situation now called for an entirely new concept. It was necessary to dispose in advance men and matériel throughout Manchuria and north Korea and to construct fortifications in all areas of operations. The main portion of the combat strength was to be concentrated along the Manchuria-Korea border where determined holding operations were to be conducted. In the meantime, each army was instructed to operate within its respective area without counting upon sustained logistical support (because of air inferiority). Raiding and guerrilla tactics were to be encouraged.
At the beginning of 1945, very few seasoned troops remained to defend central, south and southwest Manchuria against Soviet invasion and the material available to strengthen these areas was woefully inadequate.
The Kwantung Army decided to move back the headquarters of the various armies in order that they might supervise the operational preparations and to dispose the required strength in the areas farther to the rear.
On the eastern front, by the end of March, the headquarters of the 3d Army was moved back from Yehho to Yenchi and the headquarters of the 5th Army from Tungan to Yehho. At the same time, the boundary of the defense sectors of the 3d and 5th Armies was moved further south. As the Kwantung Army continued to organize its forces in Manchuria one Army headquarters, eight divisions and seven mixed brigades were mobilized. The Third Area Army Headquarters was moved back to Mukden in order that it might supervise and expedite the strengthening of the defenses and completion of new operational preparations in central and southern Manchuria. Under the Third Area Army, in July, the 30th Army Headquarters was activated and charged with the responsibility of construction in the fortified areas. Defense of northern Manchuria was transferred to the 4th Army Headquarters. On 5 June, the Kwantung Defense Army was redesignated the 44th Army and charged with the defense of western Manchuria. Altogether approximately 250,000 of the 400,000 reservists residing in Manchuria were mobilized by 10 July. This figure did not include some 150,000 men assigned to civil transportation and other duties.
In addition, the following units were organized: eight divisions (134th through 139th (inclusive) as well as the 148th and 149th); seven mixed brigades (130th through 136th (inclusive)), and a few line of communications units. The 158th Division also was to be organized as soon as possible.
While the 34th Army Headquarters (transferred from China) was engaged in defense preparations in north Korea, on 13 July, the Army General Staff issued an order specifying the action to be taken by the 34th Army should the Soviets attack the Central Sector between
the 34th Army and the Seventeenth Area Army. The main objective was to be the destruction of the attacking Soviet forces in the important regions of north Korea. Should this prove impossible, the Army was to use its main force to check the enemy's advance toward Pyongyang and part of its strength to protect Seoul.
At the same time the Army General Staff issued orders to the Seventeenth Area Army to exert every effort to prevent the enemy from establishing air and naval bases on Saishu Island by annihilating the enemy during the initial landing operations. One division was to be held in south Korea to reinforce the strength of the 58th Army at a time when an enemy landing on Saishu Island seemed imminent.
The China Expeditionary Army, contracting its front in the Hunan and Kwangsi areas, redeployed the 3d Tank Division to Inner Mongolia to strengthen preparations there and dispatched four divisions from central and north China to Manchuria and Korea. These divisions came under the command of the Kwantung Army commander as they passed over the border - the 63d Division on 19 June; 117th Division on 25 June; 59th Division on 19 July, and 39th Division on 21 July. The China Expeditionary Army continued to withdraw in southwest China, launching counterattacks to hold back the pursuing Chungking Army. On 28 July, the 11th Army Headquarters withdrew from Kweilin. On all fronts the withdrawal was carried out with very little interference from the enemy.
The initial action taken by Imperial General Headquarters toward the end of May to provide defense against the Soviet Union's entry into the war in Manchuria and Korea was regarded as totally inadequate. It, therefore, conducted further studies and, at the end of July, published the following conclusions:
Holding actions will be conducted in Manchuria and a decisive battle in Korea. If the desired operational objectives cannot be achieved, efforts will be made to hold strategic districts in south Manchuria and south Korea.
In order to build up the required strength in the Manchuria-Korea area, as many units as possible will be transferred from China.
In China, fronts in the Hunan and Kwangsi Provinces will be contracted by the end of 1945, and as many units as possible (objective, approximately ten divisions and ten brigades) will be transferred to Manchuria and Korea. At the same time, important sectors in north China will be secured against United States and Soviet attacks. This will aid the general operations of the Japanese Armed Forces.
Operations Following the Soviet Entry into the War
On 9 August the Soviet Union declared war on Japan and commenced a powerful invasion of Manchuria along a 4,000 kilometer front. The Kwantung Army commander counterattacked with units stationed along the border.
Imperial General Headquarters, immediately upon receipt of the report that the Soviet Union had entered the war, on 9 August issued an order in preparation for launching full-scale defensive operations.
The substance of the order was:
The Soviet Union has declared war against Japan. It commenced hostilities at 2400 hours on 8 August at several places along the Japanese-Soviet and the Manchukuo-Soviet borders. The action, however, is not as yet extensive.
Imperial General Headquarters intends to take immediate measures to launch full-scale operations against the Soviet Union and to destroy the enemy by employing the forces deployed in the border areas.
The Seventeenth Area Army will be placed under the command of the Kwantung Army, the transfer being effective at 0600 hours on 10 August.
The Kwantung Army Commander in Chief will counterattack with units stationed along the borders and prepare for general operations. In doing this he will bear in mind that the Kwantung Army will direct its main operational efforts against the Soviet Union in order to safeguard Japan Proper and Korea. The minimum strength necessary to meet a possible invasion by the forces of the United States will be kept in south Korea.
The Commander in Chief of the China Expeditionary Forces will take immediate steps to send part of his forces and matériel to south Manchukuo. At the same time, he will be prepared to attack Soviet forces should they attempt to invade the China area.
The operational boundary between the Kwantung Army and the China Expeditionary Army will be from Shanhaikuan through Tachengtzu, the east tip of Tarinor to Yugutszeryyn Khid. The boundary line itself will be within the area of responsibility of the China Expeditionary Army.
The commander of the Fifth Area Army will continue his current mission while, at the same
time, preparing to launch a full-scale attack against the forces of the Soviet Onion with his troops deployed along the border.
Although there was no official declaration of war against the Soviet Union, on 10 August, Imperial General Headquarters decided to launch full-scale operations against the Soviet Army and issued orders stating:
The intention of Imperial General Headquarters is to continue major operations against the forces of the United States and, at the same time, to commence full-scale operations to destroy the Soviet forces by destroying their inordinate ambition and crushing their forces, thus upholding the national polity and safeguarding the Homeland.
The Commander in Chief of the Kwantung Army will direct his main operational efforts against the Soviet Army and will destroy the enemy in order to protect Korea.
An order similar in outline to the above was issued to the Fifth Area Army. The Commander in Chief of the China Expeditionary Army was directed to assist the Kwantung Army's operations in southern Manchuria and north Korea in any way possible. At the same time, he was ordered to transfer about six divisions and six brigades with ammunition sufficient for six engagements of division strength to the Manchukuo-Korea area.
In spite of stubborn resistance by the Japanese forces, the Soviet Far Eastern Army, with its superior air power and armored forces, successfully invaded Manchuria with unexpected speed. Within a week it had advanced to the Mutanchiang Plain in the east,
Sunwu in the north, the peak of the Tahsinganling Mountain Range in the northwest and to Taoan and Taonan in the west. The critical situation in the Pacific and the threat of invasion of the Homeland prevented badly needed air force reinforcements being sent to the area. This was the situation when the termination of hostilities was announced.
Lines of Communications (Logistical Support) During Fifth Phase
Instructions had been issued to the armies located outside Japan to make themselves self-supporting as, in most cases, they were almost completely cut off from the Homeland. Within Japan, believing that an invasion of Kyushu was imminent, first priority was given to the rapid completion of logistic preparations on Kyushu and Shikoku, especially southern Kyushu and southern Shikoku. Intensive air attacks, however, prevented the planned transfer of equipment and materials from the continent and from other parts of Japan to these areas.
In an attempt to establish independent self-supporting organizations within each army district, central supply depots (which bad been established originally to supply overseas units) were reorganized and placed under the command of the local Army District commanders. In spite of efforts to stockpile munitions and to protect manufacturing plants by dispersing them, enemy air raids continued to destroy the munition dumps and plants. Air raids were also having their effect on transportation so that even food was becoming a
critical item in areas which were unable to produce their own supply. In addition to their other duties, therefore, the Army District commanders were ordered to make every effort to repair and restore to operation damaged civilian production facilities and agricultural equipment so that each area might be self-supporting. The Army District commanders were still struggling to achieve their missions when the war ended.
Termination of Hostilities
The beginning of August found all major dispositions of troops completed and the main coastal fortifications built. Preparations in Kyushu were given first priority as the Army General Staff judged that an Allied invasion of that area could be expected in September, or even sooner. Supplies, although not adequate for a long campaign, were sufficient for an initial defense and the Army General Staff believed that the first landings on Kyushu could be crushed.
But August was to bring startling developments. At 0810 on 6 August, the United States Air Force dropped the first atomic bomb on Hiroshima. Two days later they dropped a second bomb on Nagasaki, with telling effect. On 9 August, the Soviet Union, pursuing a course determined upon before the release of the atomic bombs, declared war on Japan and rapidly moved its forces into Manchuria. Greatly troubled, Imperial General Headquarters was now faced with the problem of either accepting the terms of the Potsdam Declaration or suffering an unknown fate which could possibly prove even more disastrous.
At 1030 on 9 August, the Supreme War Direction Council met at the Imperial Palace. This was the first in a series of conferences held to terminate the war. It was while it was still in session that the second atomic bomb was dropped on Nagasaki at 1130 hours.
After much discussion, although the Council agreed in principle to accept the Potsdam Declaration, it bogged down on the conditions to be attached to Japan's acceptance. Finally, the meeting recessed until after an extraordinary Cabinet meeting could be called that afternoon. At 1430 that afternoon, the first Cabinet Conference, to decide whether to seek peace immediately or to continue resistance, was opened. It was not until the 10th, however, after several conferences and much argument, that agreement was reached and a radio sent accepting the terms of the Potsdam Declaration but with the proviso that "the said declaration does not comprise any demand which prejudices the prerogatives of His Majesty as a sovereign ruler." On the 12th, the Allies replied that:
From the moment of surrender the authority of the Emperor and the Japanese Government to rule the state shall be placed under restrictions of the Supreme Commander for the Allied Powers, who will take such steps as he deems proper to effectuate the surrender terms.
The ultimate form of government of Japan shall, in accordance with the terms of the Potsdam Declaration, be established by the freely expressed will of the Japanese people.
The Foreign Minister insisted Japan should be satisfied with this reply but the War Minister, the Chief of the Army General Staff and the Chief of the Navy General Staff strongly disagreed. They firmly believed that this would mean the loss of Japan's traditional form of government, as represented by the Emperor, and argued that by continuing the war more favorable terms could be obtained. Their desire to continue the war was based on their confidence that the Kyushu Operations could be conducted successfully at least for a time.
Further conferences were held until, on the 14th, breaking tradition whereby, in the past, agreement was reached by members of the Council prior to convening a Council in the Imperial Presence, the Emperor took the initiative and convoked an Imperial Conference. After listening to the views of the Prime Minister, the Chiefs of the Army and Navy General Staff and the Army Minister, the Emperor expressed his desire to initiate procedures to end the war. Those at the meeting included Field Marshal Sugiyama, First General Army commander; Field Marshal Hata, Second General Army commander; Fleet Admiral Nagano, a member of the Board of Marshals and Fleet Admirals. These officers had been summoned as senior officers of the Army and Navy and not as field or fleet commanders.
Immediately following the Council's decision to end hostilities, the war Minister, Chief of the Army General Staff, Inspectorate General of Military Training, First and Second General Army commanders and the Air General Army commander met and vowed obedience to the Imperial decision. To make the agreement more binding, a written statement was prepared and signed by all those attending the meeting. It stated, "The Army will act strictly in accordance with the Imperial decision."
Subsequently, at 1800 hours on the 14th, a message, signed jointly by the war Minister and the Chief of the Army General Staff, was dispatched to all armies under the direct command of Imperial General Headquarters, informing them of the Imperial decision. The same afternoon the War Minister and the Chief of the Army General Staff summoned their subordinates and explained the circumstances that had led to the Imperial decision to end hostilities. At the same time, the War Minister instructed his officers to obey the Imperial decision.
On 15 August, the Navy Minister similarly instructed all naval forces to act strictly in accordance with His Majesty's desires. In addition, he summoned the chiefs of staff of all the higher headquarters in Japan and all fleet commanders and commandants of naval stations in Korea and Japan to the Navy Ministry and issued instructions concerning matters pertinent to the termination of the war.
Except for some elements which attempted uprisings on the 14th, all Army forces quietly obeyed the Imperial order.
At 1200 hours on 15 August, the Emperor, for the first time in history, made a broadcast. This was the announcement of the Imperial Rescript on the termination of the war, and proclaimed the acceptance of the terms of the Potsdam Declaration and opened the way to peace negotiations.
Although the War Minister and the Chiefs of the Army and Navy General Staffs had at first urged the continuation of the war, once the Emperor had stated his wishes, they accepted his decision. There were others, however, who could not bring themselves to accept defeat. Lt. Col. Jiro Shiizaki and Maj. Kenji Hatanaka of the Military Affairs Bureau, together with Majors Sadakichi Ishihara and Hisashi Koga, staff officers of the 1st Imperial Guards Division (believing that the entire Japanese Army would follow the example of a key unit) conspired to prevent the surrender. About noon on the 14th, Lt. Col. Shiizaki and Maj. Hatanaka and some of their supporters went to the 1st Imperial Guards Division Headquarters where they urged the Division commander, Lt. Gen. Takeshi Mori, to join the plot. Although strongly opposed to the surrender, General Mori refused to disobey the Emperor's expressed wish and, in the excitement, Maj. Hatanaka shot and killed the General. Then, issuing orders in General Mori's name, Ishihara and Koga were successful
in having the 2d Imperial Guards Division increase the guard around the Imperial Palace and cut off all contacts with the outside. In the meantime, Maj. Hatanaka searched frantically for the record on which the Emperor had recorded the Imperial Rescript which was to be broadcast the following day. He was unable to find it and events began to turn against the conspirators.
On the morning of the 15th, General Shizuichi Tanaka, commander of the Twelfth Area Army, as soon as he received news of the uprising, went to the Imperial Palace and personally withdrew the forces surrounding it. He then reported to the Imperial residence that he had the situation in hand and that there would be no further difficulty.
Lt. Col. Shiizaki and Maj. Hatanaka committed suicide in the Palace grounds and Maj. Koga took his life at the headquarters of the 1st Imperial Guards Division. Maj. Ishihara died in Ueno Park, where he was attempting to break up a demonstration by students from the Mito Army Air Signal School. Former students of Maj. Ishihara, they had assembled to protest against and fight to prevent the surrender.
Although the Imperial decision to end the war had been made and the Imperial Rescript had been broadcast, the actions of the Army and Navy had to be controlled by orders from Imperial General Headquarters. Consequently, Imperial General Headquarters immediately issued orders to suspend active operations.
On 16 August, direct radio communication was commenced in English between General MacArthur's headquarters in Manila and the Japanese Government and Imperial General Headquarters in Tokyo. At 1600 hours on the same day, Imperial General Headquarters issued an Imperial order to all Japanese Army and Navy forces to cease hostilities. The surrender of the Japanese armed forces was to be unconditional.
It is highly significant that assent to these terms and the surrender were carried out in the name of the Emperor. The traditional structure of the Japanese state remained intact.
APPENDIX NO. 1
Army Directives Army Directive No. 982 1 Nov 41 Army Directive No. 991 6 Nov 41 Army Department Orders Army Department Order No. 569 1 Dec 41 Army Department Order No. 570 1 Dec 41 Army Department Order No. 571 1 Dec 41 Army Department Order No. 572 1 Dec 41 Army Department Order No. 573 1 Dec 41 Army Department Order No. 574 1 Dec 41 Army Department Order No. 1081 24 Jul 44 Army Department Order No. 1213 26 Dec 44 Army Department Order No. 1245 6 Feb 45 Army Department Order No. 1339 30 May 45
Army Directive No. 982
1 November 1941
Pursuant to Imperial General Headquarters Army Order No. 526.
1. The orders given to Kenkichi Yoshizawa, Envoy Extraordinary and Ambassador Plenipotentiary, are given in the appendix.
2. When the Envoy Extraordinary and Ambassador Plenipotentiary is dispatched to French Indo-China, he will conduct negotiations regarding the following matters in accordance with the Matsuoka-Henry Agreement of 30 August 1940, and Article 3 of the appendix to the agreement between Japan and France dated 29 July 1941, documents exchanged between the two parties concerning the military co-operation.
Matters regarding army garrisons, billets, supplies, maneuvers, troop transportation, the use and establishment of air bases, and other matters regarding the military coordination, between the Japanese and French South Indo-China Armies.
Matters having direct bearing on the duties of the army.
3. In accordance with Army Secret China General Order No. 3506, the abovementioned official will take over the duties of the Surveillance Committee in French Indo-China following the release of its personnel; he will assume the duties of searching for materials bound for Chiang Kai-shek and, through strict surveillance, will stop the transportation of such supplies.
4. Negotiations with French Indo-China regarding military demands, for the purposes of preparing for operations against the
Southern Area, will be conducted in accordance with Imperial General Headquarters, Army Department Directive No. 957, issued 14 September 1941.
5. In conducting negotiations with French Indo-China, pursuant to the foregoing paragraphs 2 and 3, the Envoy Extraordinary and Ambassador Plenipotentiary will, beside maintaining close co-ordination in regard to negotiations, cooperate with the general policies of the other ambassadors concerning French Indo-China.
Army Directive No. 991
6 November 1941
Pursuant to Imperial General Headquarters, Army Order No. 556.
1. The Southern Army operational procedure and the Army-Navy Central Agreement regarding the Southern Area Operations, to which the Commander in Chief of the Southern Army will adhere in preparing for the Southern Area Operations, are as given in the annex.
2. The Commander in Chief of the Southern Army will complete operational preparations on or about the end of November.
3. Efforts will be made to maintain friendly relations with French Indo-China and Thailand. Local negotiations concerning military demands on French Indo-China, will include the items indicated in Imperial General Headquarters Army Department Directive No. 982 issued to the Commander of the 25th Army on 1 November 1941.
4. The Commander in Chief of the General Defense Command will order the defense units in Formosa and Nansei Islands to co-operate in air defense, garrison duties, etc., of the units under the command of the Commander in Chief of the Southern Army, which are assembled in these areas.
5. Particular care will be taken to conceal the objectives of preparations for these operations.
Army Department Order No. 569
1 December 1941
1. Japan has decided to wage war against the United States, Great Britain and the Netherlands.
2. The CinC of the Southern Army will launch offensive (Invasion) operations on X Day December.
3. In the event of the following emergencies before X Day December, the CinC of the Southern Army is authorized to take action as specified below:
a. If the enemy makes a serious initial attack on the Southern Army, offensive (invasion) operations will be launched in co-operation with the Navy at the opportune time.
b. If the British forces enter Thailand, the Southern Army, in co-operation with the Navy, will invade Thailand at the opportune time.
c. In the event enemy aircraft make repeated reconnaissance of our important bases and convoys, they will be shot down.
4. Detailed directives will be issued by the Chief of the General Staff.
Army Department Order No. 570
1 December 19411.
Japan has decided to wage war against the United States, Great Britain and the Netherlands. The Southern Army will launch offensive operations on X Day December and immediately occupy the strategic areas in the Philippines. British Malaya and the Netherlands East Indies.
2. The South Seas Detachment Commander, in co-operation with the Navy, will invade "G" immediately after X Day December. Following the occupation of "G", the South Seas Detachment Commander will concentrate his forces in this area and make preparations for operations against the "R" islands.
3. In the event that, prior to X Day December, enemy aircraft make repeated reconnaissance of our important bases and convoys, the South Seas Detachment Commander is authorized to shoot them down.
4. Detailed directives will be issued by the Chief of the General Staff.
Army Department Order No. 571
1 December 1941
1. The CinC of the Chine Expeditionary Forces will make necessary preparations to occupy the British Concession in Tientsin, the International Settlement in Shanghai and other enemy interests in China.
2. Detailed directives will be issued by the Chief of the General Staff.
Army Department Order No. 572
1 December 1941
1. Japan bad decided to wage war against the United States, Great Britain and the Netherlands.
2. The CinC of the China Expeditionary Forces will cooperate with the Navy and occupy Hong Kong with a force organized around the 38th Division under the command of the 23d Army Commander. Operations will be launched immediately after the Southern Army's landings on or air raids upon Malaya are confirmed. After Hong Kong is occupied, the neighboring areas will be secured and a military government established.
3. In the event of the following occurrences, the CinC of the China Expeditionary Forces is authorized to take action as specified below:
a. In the event the enemy makes an initial attack before the commencement of operations, the attack will be intercepted at an opportune time.
b. In the event enemy aircraft carry out repeated reconnaissance of our military movements, etc., they will be shot down.
4. Detailed directives will be issued by the Chief of the General Staff.
Army Department Order No. 573
1 December 1941
1. The CinC of the China Expeditionary Forces will occupy the British Concession in Tientsin, International Settlement in Shanghai and other enemy interests in China. If considered necessary, use of force is authorized.
2. Detailed directives will be issued by the Chief of the General Staff.
Army Department Order No. 574
1 December 1941
1. The units given in the annex will be placed under the command of the Shipping Transport Commander and incorporated into the orders of battle of the Southern Army, 15th Army, loth Army and 25th Army.
2. Officers ordered to organize the units and the Korea Army Commander will place the units named in the annex under the command of their newly assigned commanders at their present stations or by dispatching them to the south.
3. Transfer of command will be effective when the units given in the annex depart from ports in Japan, Korea or China. The Southern Army Kempeitai, 1st Field Construction Unit Headquarters and the 1st Sea Transport Observation Unit, however, will be placed under the command of their newly assigned commanders at 0001 hours, 1 December.
4. Each newly assigned commander of the units given in the annex is authorized to exercise delegated command over these units in regard to operational preparations before they come under his command.
5. Detailed directives will be issued by the Chief of the General Staff.
Units to be incorporated into order of battle of Southern Army:
Southern Army Kempeitai
Commander: 2d Field Kempeitai Commander
2d Field Kempeitai Headquarters (61st Ind Inf Group)
4th Field Kempeitai (25th Army)
Note: The 2d Field Kempeitai Headquarters will be removed from the order of battle of the Southern Army and incorporated into the organization of the Southern Army Kempeitai.
Units to be incorporated into the organization of the air units directly assigned to Southern Army:
Air Research Division, Southern Army (Army Aeronautical Department)
1st Field Air Replacement Unit (1st Air Group (Hiko Shudan)
Units to be incorporated into the organization of the line of communications units directly assigned to the Southern Army;
17th Field Post Office Unit (Guards Depot Div)
17th L of C Veterinary Hospital (57th Depot Div)
1st Tracked Vehicle Repair Unit (Guards Depot Div)
Units to be incorporated into the order of battle of the 15th Army:
Communications Unit, 15th Army
Commander: 15th Signal Unit Commander
15th Signal Unit Headquarters (CinC, China Expeditionary Forces)
6th and 7th Ind Signal Companies (pack horse) (5th Depot Div)
Note: The following signal units in the order of battle of the 15th Army will be incorporated into the organization of the 15th Army Signal Unit.
23d Independent Signal Company (B) (pack horse) (7th Div)
87th Independent Signal Company (motorized) (5th Depot Div)
38th and 43d Fixed Radio Units (5th Depot Div)
Units to be incorporated into the organization of the line of communications units of the 15th Army and placed in the 15th Army order of battle:
101st Ind Motor Transport Battalion (Guards Depot Div)
51st Independent Transport Battalion (A) (3d Depot Div)
33d Sea Duty Company (51st Depot Div)
35th Sea Duty Company (52d Division)
101st Construction Duty Company (Guards Depot Div)
39th and 40th Casualty Clearing Platoons (51st Depot Div)
Units to be removed from the command of the Korea Army Commander and incorporated into the line of communications unit directly assigned to the 15th Army:
73d L of C Sector Unit (20th Div)
93d and 94th Land Duty Companies (53d Div)
Unit to be incorporated into line of communications unit directly assigned to the 10th Army.
102d Ind Motor Transport Battalion (61st Ind Inf Group)
Force to be incorporated in the order of battle of the 25th Army:
56th Division (56th Div)
Units to be placed under the command of the Shipping Transport Commander:
1st Field Construction Unit Headquarters (61st Ind Inf Group)
1st Sea Transport Observation Unit (Shipping Transport Commander)
Army Department Order No. 1081
24 July 1944
1. Imperial General Headquarters plans to direct a decisive battle against the main body of the United States forces during the latter half of this year. It is estimated that the Imperial Army will fight this decisive battle in Japan Proper, the Philippines or the area between. Imperial General Headquarters will determine later the exact time and place of this decisive battle.
2. The Commander in Chief of the Southern Army, the Formosa Commander, Commander in Chief of the General Defense Command, Fifth Area Army Commander, and the Commander in Chief of the China Expeditionary Forces will co-operate with the Navy in making immediate preparations for the decisive battle and the fulfilment of their assignments. The outline of the tactical command policy to be pursued by Imperial General Headquarters in directing future operations is as shown in the appendix.
3. In order to carry out the decisive battle, the Chief of the General Staff is authorized, within the scope of plans to be made, to issue directives to the commanders concerned for the employment (including the transfer of command) and preparations of the air force.
By Imperial Command:
Chief of the General Staff
To: Yoshijiro Umezu, Chief of the General Staff
Count Hisaichi Terauchi, Commander in Chief, Southern Army
Shunroku Hata, Commander in Chief, China Expeditionary Forces
Prince Naruhiko, Commander in Chief, General Defense Command
Rikichi Ando, Commander, Formosa Army
Kiichiro Higuchi, Commander, Fifth Area Army
Army Department Order No. 1213
26 December 1944
1. In addition to his present duties, the Commander in Chief of the General Defense Command will carry out the following air operations:
a. Air operations in the Marianas and Iwo Jima areas.
b. Air operations in the Nansei Islands area, with Kyushu as base.
By Imperial Command:
Chief of the General Staff
To: Prince Naruhiko, Commander in Chief, General Defense Command
Army Department Order No. 1245
6 February 1945
1. Imperial General Headquarters intends to destroy the advancing enemy, particularly the American forces, our principal foe, and to secure the strategic national defense areas centered around the Homeland, thereby destroying the enemy's will to fight.
2. The Commander in Chief of the General Defense Command will secure Japan by annihilating the invading enemy. The essentials of the plans which must be adhered to in accomplishing the foregoing mission are as follows:
a. Operational preparations in Japan will be stressed, particularly in the Kanto, Kyushu and Tokai districts. Special emphasis will be placed on the air defense of key points in the foregoing sectors and the Osaka-Kobe district.
b. In addition to intercepting enemy air raids at an opportune time, the Commander in Chief of the General Defense Command will cooperate with the Navy in exerting every effort to destroy enemy task forces attacking the vicinity of Japan.
c. Efforts will be made to destroy the enemy at sea so as to prevent an invasion of the Homeland.
d. Protection of land transportation routes and harbor installations will be maintained with special emphasis being placed on guarding key points of surface transportation between Japan and Korea.
e. The Navy will be given as much assistance as circumstances will permit in the protection of surface transportation.
f. The Commander in Chief of the General Defense Command will, if necessary, confer and cooperate with the Commander in Chief of the Kwantung Army, Commander in Chief of the China Expeditionary Forces, Fifth Area Army Commander, Tenth Area Army Commander, Seventeenth Area Army Commander and Navy commanders concerned in regard to the foregoing operations. He will dispatch a part of his forces to other armies' zones of operations and reorganize command relationships accordingly.
g. Air operations outside the zone of operations will he based upon Imperial General Headquarters Army Department Order No. 1213.
3. The Seventeenth Area Army Commander will secure Korea by annihilating the invading enemy. He will be subject to the delegated command of the Commander in Chief of the Kwantung Army for such matters as operational preparations against the Soviets. The essentials of the plans which must be adhered to in accomplishing the foregoing missions are as follows:
a. Operational preparations in Korea will be stressed around the key sectors of the south Korea area (including Saishu Island).
b. Key points of the trans-peninsula railroad (running the length of Korea), northern Korea railway and the Yalu and Toukou Rivers will be guarded strongly.
c. The Seventeenth Area Army Commander will, if necessary, confer and cooperate with the Commander in Chief of the General Defense Command, Commander in Chief of the Kwantung Army and Navy commanders concerned in regard to the foregoing operations and dispatch a part of his forces to other armies' zones of operations and reorganize command relationships accordingly.
4. The boundary between the zones of operations of the Japan Defense Army and the Fifth Area Army will be Tsugaru Strait with the Tsugaru Strait and the Tsugaru Fortified Zone in Aomori Prefecture being under the control of the Fifth Area Army. The boundary between the zones of operations of the Japan Defense Army and Tenth Area Army will be Lat. 30°10'N. The boundary between the zones of operations of the Japan Defense Army and Seventeenth Area Army will be Korea Strait.
5. Directives concerning the details will be issued by the Chief of the General Staff.
By Imperial Command:
Chief of the General Staff
To: Prince Naruhiko, Commander in Chief, General Defense Command
Kiichiro Higuchi, Commander, Fifth Area Army
Rikichi Ando, Commander, Tenth Area Army
Seishiro Itagaki, Commander, Seventeenth Area Army
Otozo Yamada, Commander in Chief, Kwantung Army
Yasuji Okamura, Commander in Chief, China Expeditionary Forces
Army Department Order No. 1339
30 May 1945
1. Imperial General Headquarters plans to strengthen preparations for operations against the United States and the Soviet Union in Korea and Manchuria.
2. The Commander of the Seventeenth Area Army will annihilate the enemy invading central and southern Korea.
3. The Commander in Chief of the Kwantung Army will, in addition to carrying out his present mission, annihilate the American Army when it attacks, and at the same time, make preparations for operations against the Soviet Union in northern Korea. For this purpose the necessary units under his over-all and direct command will be disposed in northern Korea. The Commander of the Korea Area Army will be under his command in regard to preparations for operations against the Soviet Union in northern Korea and operations against the United States.
4. For the defense of northern Korea, the Commander of the Korea Area Army will assume command of the units disposed according to the preceding paragraphs; his authority, however, will be limited to matters which do not interfere with the units' preparation for operations.
5. Detailed directives will be issued by the Chief of the General Staff.
By Imperial Command:
Chief of the General Staff
To: Otozo Yamada, Commander in Chief, Kwantung Army
Yoshio Kotsuki, Commander, 17th Area Army
Yoshio Kotsuki, Commander, Korea Area Army
APPENDIX NO. 2
Chronology of Major Events During War
1941 Jul 2 Imperial General Headquarters ordered the Kwantung Army Special Maneuver. 28 Japanese Army advanced into South French Indo-China. 29 Mutual Defense Agreement concluded between Japan and French Indo-China. Oct 18 Third Konoye Cabinet resigned and Tojo Cabinet formed. Nov 26 Hull Note issued. Dec 8 Outbreak of Pacific War. 9 15th Army advanced to Bangkok. 11 Japan, Germany and Italy agreed not to sign separate peace treaties with the Allies. 21 Japan-Thai land Military Alliance concluded. 1942 Jan 2 14th Army captured Manila. 18 Japan-Germany-Italy Military Alliance. Feb 8 14th Army's attack on Bataan temporarily suspended. 15 25th Army captured Singapore. Mar 8 15th Army captured Rangoon. 9 Dutch Forces surrendered in Netherlands East Indies. Apr 3 14th Army's attack on Bataan resumed.
Apr 9 14th Army occupied Bataan. 18 U.S. task force made first air raid on Japan. May 7-8 Naval battle of Coral Sea. Jun 5 Naval battle of Midway. 7 North Seas Detachment landed on Kiska. 8 North Sea Detachment landed on Attu. Jul 1 Navy forces landed on Guadalcanal. Aug 7 Allies landed on Guadalcanal and Tulagi. 20-21 Ichiki Detachment counterattacked on Guadalcanal. Sep 5 South Seas Detachment captured summit of Oven Stanley Mountain Range. 12-14 First general attack by Kawaguchi Detachment on Guadalcanal. 26 South Seas Detachment began withdrawal from Owen Stanley Range. Oct 24-25 Second general attack by 2d Division on Guadalcanal. Nov 10 Activation of Eighth Area Army. Dec 31 Decision to withdraw from Guadalcanal. 1943 Jan 20 Japanese commence withdrawal from Buna Sector. Feb 1-7 Japanese withdraw from Guadalcanal. Mar 3 51st Division sunk in Dampier Strait. May 12 Allies landed on Attu.
Jun 30 Allies landed on Rendova Island, Solomons, and Nassau, New Guinea. Jul 29 Japanese commence withdrawal from Kiska. Aug 1 Declaration of Independence by Burma. 1 Signing of Japan-Burma Alliance Pact. Sep 4 Allies landed at Hoppoi, east of Lae. 8 Italy surrendered. 22 Allies landed at Finschhafen. 28 Decision made to establish Munitions Ministry. Oct 14 Declaration of Independence by the Philippines. 21 Establishment of Provisional Government of Free India. Nov 1 Allies landed on Torokina. 5-6 Greater East Asia Convention held at Tokyo attended by leaders from Japan, Manchukuo, Nanching Government, Philippines, Thailand and Burma. Nov 21 Allies landed on Makin and Tarawa. 23 Cairo Conference. 28 Teheran Conference. Dec 26 Allies landed on Cape Gloucester. 1944 Feb 1 Allies landed on Kwajalein. 17 Allied task force attacked Truk. 18 Allies landed on Eniwetok.
Feb 23 Allied task force attacked Marianas. 29 Allies landed on Admiralties. Mar 8 Imphal Operation started. Mar 30 thru Apr 3 Allies attacked Palau and Hollandia. 18 First Phase of "ICHI-GO" Operation started. 22 Allies landed on Hollandia. May 27 Allies landed on Biak. 27 Second Phase of "ICHI-GO" Operation started. Jun 15 Allies landed on Saipan. 19-20 "A-GO" Operation (Naval Battle off Marianas). Jul 8 China-based, B29's first raided Kyushu. 22 Tojo Cabinet resigned and Koiso Cabinet formed. 29 China-based B29's first raided Manchuria. Sep 15 Allies landed on Peleliu and Morotai. Oct 12-16 Air battle off Formosa. 20 Allies landed on Leyte. 24-26 Philippines Sea Battle. Nov 9 President Roosevelt elected for the fourth time. 10 China Expeditionary Army occupied Kweilin and Liuchow, 24 Allied Saipan-based B29's raided Tokyo area for first time. Dec 15 Allies landed on Mindoro.
1945 Jan 9 Allies landed at Lingayen Gulf. Feb 19 Allies landed on Iwo Jima. 26 Allies entered Manila. Mar 9 Southern Army began to dispose forces in French Indo-China. 9-10 First Allied air raids on Tokyo using incendiary bombs. 26 "TEN-GO" Air Operations commenced. Apr 1 Allies landed on Okinawa. 5 Soviet declared intention to abrogate Russo-Japanese Neutrality Pact. 7 Koiso Cabinet resigned and Suzuki Cabinet was formed. May 3 Allies occupied Rangoon. 8 Germany surrendered. Jul 26 Three Power Joint Declaration issued at Potsdam. Aug 6 First atomic bomb dropped on Hiroshima. 9 Soviet entered war. 9 Second atomic bomb dropped on Nagasaki.
APPENDIX NO. 3
Chronology of Major Liaison Conferences During Greater East Asia War
1941 Sep 6 Council in Imperial Presence decided to make further efforts to solve the tense Japanese-American situation by peaceful methods. At the same time preparations for war were to be initiated, so that Japan would be ready to defend her entity as a sovereign nation should diplomatic negotiations fail. Nov 5 Council in Imperial Presence decided to concentrate efforts on preparations for war while still seeking to break deadlock by diplomatic means. Nov 15 Liaison Conference decided on outline of objectives titled "Tentative Plan to Expedite the Termination of War with the U.S., Britain, China and the Netherlands." 20 Liaison Conference decided on outline of administration of occupied Southern Areas. 23 Liaison Conference decided on measures to be taken toward Thailand. Dec 1 Council in Imperial Presence resolved to open hostilities against U.S., Britain and the Netherlands. 1942 Mar 7 Liaison Conference adopted "General Outline of War Direction Policies to be carried out in the Future", at which an estimate of the world situation and Japan's strength was made. Dec 10 Council in Imperial Presence agreed upon "Matters Relating to a Readjustment between Requirements for Operations and National Material Strength in the Conduct of War and the Maintenance and Strengthening of National Power."
1942 Dec 21 Council in Imperial Presence agreed upon "Basic policy toward China in order to carry out the Greater East Asia War." 1943 May 31 Council in Imperial Presence approved "Outline Plan for the Direction of Greater East Asia Political Strategy", main point of which was to accelerate the independence of Philippines and Burma. Sep 30 Council in Imperial Presence approved "Outline Plan for the Direction of Future War", in which the Council decided on last line to be secured for national defense as recommended by Imperial General Headquarters. At this meeting it was decided to increase aircraft production. 1944 Aug 4 Liaison Conference reorganized into Supreme Council for the Direction of War. 19 Council in Imperial Presence adopted "Outline Plan for the Direction of War", at which it was decided to continue the war and defend the Homeland to the last man. 1945 Jan 25 Supreme Council for the Direction of War approved "Outline of Emergency Measures to Support the Decisive Battle." Jun 8 Council in Imperial Presence adopted basic policy for preparation of Homeland decisive battle. Aug 10 Council in Imperial Presence agreed upon acceptance of Potsdam Declaration with an understanding concerning status of the Emperor. 14 Council in Imperial Presence agreed upon unconditional acceptance of Potsdam Declaration.
APPENDIX NO. 4
Chronology of Major Actions and Decisions by the Army General Staff
1941 mid-Sep Issued orders concerning preliminary war preparations, organizing operational forces and dispatching them to South China, Formosa and French Indo-China. Nov 6 Issued orders of battle of Southern Army, 14th Army, 15th Army, 16th Army, 25th Army and South Seas Detachment. Ordered Armies to carry out preparations for Southern Invasion Operations. 15 Issued preliminary order to carry out Southern Invasion Operations. D-Day was to be announced by separate order. 26 An agreement was reached between the Army and Navy regarding division of responsibility for military administration of occupied Southern Area. Dec 1 Issued order naming 8 December as D-Day. 3 Instructed Kwantung Army to avoid any border dispute with the U.S.S.R. Instructed China Expeditionary Army to strengthen anti-Chungking blockade and to weaken Chungking's will to continue war. late-Dec Decided to advance Java Invasion Operation by one month. 1942 Jan 4 Ordered South Seas Detachment to occupy Rabaul. 22 Ordered Southern Army to expand operations in Burma to capture all important areas. Feb 2 Ordered South Seas Detachment to capture important points in British New Guinea and the Bismarck Archipelago.
Feb 7 Ordered Southern Army to capture Andaman Islands and authorized it to operate in Portuguese Timor. 10 Placed 4th Division under the command of l4th Army to strengthen the Bataan offensive. mid-Mar Tentative plan for direction of subsequent military operations following completion of Southern Invasion Operations was established, main point of which was consolidation of occupied Southern Area and conservation of fighting power. Mar 20 Issued first of a number of orders transferring part of air and ground forces from Southern Army to Manchuria, Homeland and China. late-Mar Began studies on Hew Caledonia-Fiji-Samoa and Western Aleutian Operations on the basis of a tentative agreement between the Army and Navy to carry out these operations. early-Apr Published a plan to conclude the China Incident by launching an attack against Chungking. Apr 20 Issued order of battle of the Borneo Garrison Army. 30 Ordered the China Expeditionary Army to capture air bases in Chekiang Province. May 5 Issued orders of battle of Ichiki and North Seas Detachments and assigned them the mission of capturing Midway Island and the Western Aleutian Islands, respectively. 18 Issued order of battle of the 17th Army and assigned it the mission of invading Fiji, Samoa and New Caledonia. Jun 27 Placed 14th Army under the direct command of Army General Staff. 29 Ordered the Southern Army and the 14th Army to stabilize and secure occupied areas. Army-Navy Central Agreement was concluded regarding defense policy and defense responsibility in the occupied Southern Areas.
Jul 4 Activated the first and Second Area Armies, Tank Army and 2d Army under the Kwantung Army to strengthen war preparations in the north. 10 Activated the 3d Air Army under the Southern Army. 11 Cancelled New Caledonia-Fiji-Samoa Operation Plan and ordered the 17th Army to capture Port Moresby and mop up eastern New Guinea. Aug 13 Assigned the 17th Army the additional mission of recapturing Guadalcanal and Tulagi. 29 Issued order to reinforce 17th Army with the 2d Division. 31 Issued order giving recapture of Guadalcanal priority. Sep 3 Ordered the China Expeditionary Army to carry out preparations for Chungking Operation. Nov 16 Issued orders of battle for Eighth Area Army and 18th Army, effective date 26 November. Instructed Eighth Area Army to strengthen Southeastern Area and recapture Guadalcanal. Dec 10 Cancelled order to prepare for Chungking Operation. 31 Army and Navy General Staffs decided on new operations policy to withdraw units from Guadalcanal. Adjusted the front line in the Southeastern Area to the northern Solomons-New Britain Island-eastern New Guinea line. 1943 Jan 4 Issued orders to Eighth Area Army in support of the 31 December decision. 7 Activated 19th Army under Southern Army to strengthen preparations in North-of-Australia Area. 30 Ordered the China Expeditionary Army to occupy important points on Luichow Peninsula and in the French Leased Territory along Kuangchow Bay.
Feb 11 Redesignated Northern District Army as Northern Army giving it the status of an operational army. late-Feb Published a plan to direct Southwest Pacific Area operations during 1943. Mar 27 Activated Burma Area Army under Southern Army to strengthen command system in Burma. Apr 12 Took first step to strengthen ground operational preparations in Central Pacific Area by dispatching 1st and 2d South Seas Defense Units (Army) to that area. May 20 Issued order to withdraw units from western Aleutians. Jun 19 Issued orders to dispatch 7th Air Division and 1st Raiding Group to New Guinea in preparation for Bena-Bena Operation. Jul 28 Activated 4th Air Army under Eighth Area Army command to strengthen air operations in Southeastern Area. Aug 30 Issued order to adjust main defense position in New Guinea from Lae-Salamaua to Finschhafen area. Sep 15 Army and Navy General Staff decided on new operations plan to establish a firm national defense line extending from Banda Sea area to Marianas through western New Guinea and Carolines. 30 Ordered Southern Army to strengthen operational preparations in North-of-Australia Area, also ordered Eighth Area Army to shift to a delaying action. Oct 29 Ordered transfer of Second Area Army headquarters and 2d Army headquarters from Manchuria to North-of-Australia Area to strengthen operational preparations there. Ordered the Second Area Army to assume command of North-of-Australia Area under direct command of Army General Staff. Nov 15 Took first step to strengthen operational preparations on Ogasawara Islands by dispatching 1st and 5th Independent Mixed Regiments to that area. Dec 10 Issued orders of battle of French Indo-China Garrison Army and Thailand Garrison Army.
1944 Jan 7 Approved execution of Imphal Operation by Southern Army. 15 Activated 28th Army under Burma Area Army to strengthen operations in Akyab area. 15 Activated 29th Army in northern Malaya. 24 Ordered China Expeditionary Army to carry out Hunan-Kwangsi ("ICHI-GO") Operations. Feb 15 Activated 5th Air Army under China Expeditionary Army command. 25 Activated 31st Army in Central Pacific Area to consolidate operational preparations there. Placed the 31st Army under the command of the Combined Fleet. early-Mar Began joint studies with the Navy for "A-GO" Operations. Mar 14 Issued order to transfer 18th Army and 4th Air Army from Eighth Area Army to Second Area Army. Effective date 25 March. 16 Redesignated the Northern Army as Fifth Area Army. Activated 27th Army in Kuriles under the Fifth Area Army command to strengthen operational preparations there. Effective date 27 March. 22 Issued orders of battle of Formosa Army and 32d Army and directed them to strengthen operational preparations on Formosa and Nansei Islands respectively (Battle Preparations No. 10). 27 Activated Seventh Area Army at Singapore under Southern Army. 27 Placed Second Area Army and 14th Army under Southern Army command to simplify command system in the South. Effective date 15 April. Apr 11 Activated 33d Army in northern Burma.
early-May Issued order directing "Battle Preparations No. 11" to strengthen the Philippines. May 2 Ordered Southern Army to contract first line in western New Guinea to Manokwari-Sorong-Halmahera line. 4 Ordered Homeland Defense commander to strengthen defense of Homeland and placed Eastern, Central and Western District Armies, and all Air Defense Divisions and Brigades in the Homeland under his command. 9 Ordered Southern Army to contract first line in western New Guinea to Sorong-Halmahera line. 12 Ordered transfer of 2d and 4th Air Divisions from Manchuria to the Philippines to strengthen operational preparations there. Jun 15 Activated four divisions in the Philippines and placed them under 14th Army command. 26 Issued order of battle of Ogasawara Group under direct command of Army General Staff. Jul 4 Directed Southern Army to discontinue Imphal Operation. 11 Placed 32d Army under Formosa Army command. 18 Ordered China Expeditionary Army to capture important points along the southeast coast of China. 21 Organized 36th Army under direct command of Army General Staff to strengthen the defense of Homeland. 24 Issued order regarding battle preparations for "Sho" Operations. late-Jul Measures taken to unify operations of Army and Navy Air Forces in various local areas. Aug 4 Redesignated 14th Army in the Philippines as Fourteenth Area Army. Activated 35th Army under Fourteenth Area Army.
Aug 26 Activated Sixth Area Army under China Expeditionary Army to support Hunan-Kwangsi Operation. mid-Sep Ordered Kwantung Army to defend Manchuria by general delaying tactics. mid-Sep Ordered Southern Army to secure southern Burma and to cut Burma-Yunnan route. Sep 22 "Sho" Operation, No. 1 (for the Philippines area) given top priority. 22 Redesignated Formosa Army as Tenth Area Army. Oct 18 Nov 1 Ordered execution of "Sho" Operation, No. 1.
Issued order to expedite the execution of "Sho" Operation, No. 1.
mid-Dec Took measures to exploit a more effective use of Continental Railways. Dec 26 Activated 6th Air Army to strengthen air defense operations in the Homeland. 1945 mid-Jan Decided on a new outline plan of decisive operations to protect strategic sphere around the Homeland. Jan 16 Ordered Kwantung Army to mobilize eight divisions and four mixed brigades. 22 Ordered China Expeditionary Army to shift its main efforts from anti-Chinese operations to anti-American operations and to speed up operational preparations along southeastern coast of China. 26 Ordered transfer of 6th Army headquarters from Manchuria to China to strengthen command system in lower reaches of Yangtze River.
Jan 27 Ordered Southern Army to direct its operations so that the Army should obstruct enemy advances toward China and the Homeland. early-Feb Ordered China Expeditionary Army to mobilize three divisions, 12 mixed brigades and seven independent garrison units. Feb 3 Ordered Tenth Area Army to secure Formosa and Nansei Islands, and repel advance of enemy air and sea bases in that area. 6 Issued order of battle for Homeland Defense Army and, under its command, activated the Eleventh, Twelfth, Thirteenth, Fifteenth and Sixteenth Area Army Headquarters and four mixed brigades in the Homeland, Also activated Civil Defense Forces. Redesignated Korea Army as Seventeenth Area Army and Korea Army District. Activated two divisions in Korea. 6 Issued orders concerning air operations in east China Sea Area ("TEN-GO" Air Operation). 26 Decided on General Mobilization Plan for Homeland Defense, calling for mobilization of 42 divisions, 19 mixed brigades and six tank brigades in three groups. 28 Issued order for First Group Mobilization. 28 Ordered Southern Army to occupy French Indo-China with armed forces, if necessary. Mar 1 Army-Navy Central Agreement regarding Air Operations for the First half of 1945 was concluded and issued. 19 Placed 6th Air Army under Combined Fleet command. 20 Disclosed rough draft plan of "KETSU-GO" Operations to chief of staff of each area army. 31 Issued order to transfer four divisions from Manchuria to the Homeland.
Apr 2 Issued order for Second Group Mobilization. 8 Activated First and Second General Armies and Air General Army in the Homeland. Homeland Defense Army was inactivated, effective date 15 April. 8 Published "KETSU-GO" Operation Plan for defense of Homeland and Korea. 18 Ordered China Expeditionary Army to assemble four divisions in north-central China from south China. May 5 Decided to transfer one Army headquarters and four divisions from China to Kwantung Army. 8 Instructed Fifth Area Army to direct its main efforts to the defense of Hokkaido. Also gave the Army an outline plan for anti-Soviet defense. 10 Issued order to transfer 40th Army Headquarters from Formosa to Kyushu. 23 Issued order for Third Group Mobilization. 26 Returned 6th Air Army to Air General Army command. 30 Ordered China Expeditionary Army to withdraw from Hunan-Kwangsi area and strengthen strategic positions in north-central China. Also ordered transfer of four divisions from China to Kyushu. 30 Issued order of battle of Kwantung Army. Instructed the Army to prepare for anti-Soviet defense operations with main objective to secure southern Manchuria. Also authorized the Army to dispatch a part of its forces in northern Korea and to the control of Korea Army in regard to operational preparations. late-May Kyushu given first priority in defense of the Homeland. Jun 23 Activated Tokyo Defense Army under First General Army. 28 Took measures to maintain sea transportation in Korean Strait and Japan Sea.
Jun 30 Returned all air defense units (flying units) to Air General Army command from General Armies' command. Instructed Air General Army to strengthen air defense against B29s. Jul 10 Effected total mobilization in Manchuria and mobilized eight divisions and seven mixed brigades. mid-Jul Issued Army-Navy Air Agreement for "KETSU-GO" Operations. Jul 26 Directed Southern Army to hold southern Burma and Sumatra as long as possible, while firmly securing Malay, Thailand and French Indo-China as central sectors in the south. Aug 9 Ordered Kwantung Army and Fifth Area Army to prepare for an all-out defense operation against the Soviet. 9 Placed the Seventeenth Area Army under Kwantung Army command. 9 Ordered China Expeditionary Army to send six divisions and six brigades to Manchuria. Ordered Kwantung Army and Fifth Area Army to commence all-out defense operations. 14 Instructed all the Army forces to faithfully obey the Imperial Decision to end the war. Issued order to suspend all attacks against Allied forces. 16 Issued order to cease all hostile activities.
APPENDIX NO. 5
Guide to Designation of Units, Their Missions and Normal Size
Designation Normal Mission Normal Size Example Independent Mixed Regiment Defense of isolated island or isolated point 3 inf bns 4th Indep Mixed Regt 1 arty bn 1 engr co Border Garrison Unit Garrison of border in Manchuria 3 to 10 inf bns 5th Border Garrison Unit 3 to 10 arty bns 1 to 4 engr cos Detachment Combat team for specific purpose (Temporarily organized) 2 to 3 inf bns South Seas Det 5th South Seas Det Kawaguchi Det 1 arty bn 1 tank co 1 engr co Defense Unit Defense of isolated island 3 inf bns 1st South Seas Defense Unit 1 arty bn 3 tank cos 1 sig co Independent Garrison Unit Garrison of railroads in Manchuria 4 to 6 inf bns 1st Independent Garrison Unit Expeditionary Unit Unit temporarily organized from units stationed in Manchuria and Korea to reinforce troops in Central Pacific 3 to 6 inf bns 1st Expeditionary Unit 1 to 2 arty bns 1 to 2 engr cos Mixed Infantry Group Combat team for specific purpose (Temporarily organized) 3 inf bns 56th Mixed Infantry Group (Sakaguchi Det) 1 arty bn 1 engr co Independent Brigade Originally formed to garrison occupied areas. Later used for combat. 3 inf regts 65th Brigade 1 engr unit 1 sig unit Cavalry Brigade Combat unit 2 to 3 cavalry regts 1st Cavalry Brig 1 tank unit 1 arty unit 1 engr unit
Guide to Designation of Units, Their Missions and Normal Size (Cont'd)
Designation Normal Mission Normal Size Example Independent Tank Brigade Combat unit formed for defense of the Homeland 2 tank regts 1st Independent Tank Brig 1 machine gun unit 1 maintenance unit Amphibious Brigade Unit specially organized for Landing operation 3 mobile inf bns 1st Amphibious Brig 1 tank unit 1 machine gun unit 1 engr unit Independent Mixed Brigade Combat team for general purpose 3 to 6 inf bns 68th Indep Mixed Brig 1 arty unit 1 engr unit Fortress Unit Defense of fortress 1 to 2 hvy arty regts Tokyo Bay Fortress Unit Some inf units 1 AAA unit 1 engr unit Cavalry Group Combat unit 2 cavalry brigs 3d Cavalry Group 1 sig unit Division Combat unit 1 inf gp hq 1st Division 3 inf regts 1 rcn (cavalry) regt 1 arty regt 1 engr regt 1 sig unit Tank Division Combat unit 3 tank regts 2d Tank Division 1 inf regt 1 rcn unit 1 arty regt 1 AAA unit 1 anti-tank gun unit 1 engr unit
Guide to Designation of Units, Their Missions and Normal Size (Cont'd)
Designation Normal Mission Normal Size Example Group Common name of such units as division, tank division, cavalry group, independent mixed brigade, etc. Commander of a group was a general with one or more general staff officers. Army General field operation Varied according to the operational need. Normally composed of one or more divisions, other combat units and necessary line of communications units. 1st Army Mongolia Garrison Army Garrison Army Garrison Varied according to need. Normally composed of garrison units and military administrative organs. Borneo Garrison Army Thailand Garrison Army Armored Army Armored Army was established, in 1942, with 1st and 2d Tank Division as its nucleus. Area Army General field operations Varied according to need. Normally composed of one or more armies, other combat units directly assigned and line of communications units. Second Area Army Burma Area Army
ABCD: rejects Japan's plan, 33
Adak: 85; landing cancelled, 86
Aden: Allied naval strength near, 38
Admiralty Is: 147; 170; 176; 184
Africa: Allied naval strength near, 38; 40; est enemy strength in, 79; 140
A-GO Opn (See Operations)
Air Armies, Japanese
1st: 136; 159; 195; 232; 286; disposition of, 324
2d: 77; 286
3d: 77; order of battle, 91; 92; 136; 165; 168; 186; 222; strength Mar 45, 277; 280; 326
4th: organized, 128; to 2d Area Army, 175; 185-7; 200; 205; 215; 217; 219; 220-1; 232; 280
5th: 164-6; strength Mar 45, 277; 304; 309-10; 324
6th: 229; 258; strength Mar 45, 277; 279; 286; 300; 302-4; 324; 327
Airborne Raiding Group, 1st: 220; 280
Air Brigades, Japanese
1st: 21; 128
2d: (Airborne Raiding) 220
3d: 136; 280
10th: (Ind) 280
Air Divisions, Japanese
1st: 136; 159; 179; 205; 231
2d: to Philippines, 186-7; 280
3d: to China Exp Army, 92; 166
4th: to Philippines, 186-7; 280
5th: 92; 133; 186; 222; 326
6th: 111; reinforced, 127-8
7th: 127-8; 136; 156; 186; 280; 326
8th: 182; 205; 232; strength Mar 45, 277; 279; 301; 304
9th: 168; 186; 280; 326
10th: 205; 210; 286; 319
11th: 205; 210; 286; 319
12th: 205; 210; 286; 319
13th: 304; 309
51st, Trng: 286
52d, Trng: 286
53d, Trng: 286
Air Fleets, Japanese
1st: 191; 205; 232; strength Mar 45, 278
2d: 205; 232
3d: 205; strength Mar 45, 278; 299; 300; 325
5th: strength Mar 45, 278; 299; 300-1; 325
10th: strength Mar 45, 278; 299-300; 325
12th: 205; 231; 232
Air Force, British: 81
Air Force, Japanese: 16; 94
Air Force, U.S.: 81; in China, 107
Air General Army: 282; 285-7; 303; 310; 319-20; 322; disposition of, 324; 327; 340
Air Groups, Japanese
2d: 21; 31
3d: 21; 44
5th: 21; 31; 44; 52; in Burma, 70
30th: (Fighter) 215; 280; 286
Air Homeland Defense Force (Navy): strength Mar 45, 278
Airplane production: est enemy increases, 80
Air Regiments, Japanese
7th: 232; 326
24th: 280; 326
98th: 232; 326
Air Squadrons, Japanese
31st, Indep: 280
Air Training Army Hq: 210; inactivated, 229
Air Units, Japanese
Airborne, 1st: 67
Bangkalangbrandan Defense: 168
Palembang Defense: 168
20th Indep: 280
21st Indep: 21; 44
Aitape: 170; 176
Akyab: airfield occupied, 70; 118; 122; 132; 133; 135
Alaska: est enemy strength in, 78; 143
Aleutians: 77; est enemy strength in, 78; forces to be used agst, 84; IGH ordered occupation of, 85-6; 107; 115; 121; 143-4; 172; 178
Allied strength and disposition Sep 43: 141-2; increased strength, 143
Amami Oshima: 43; 304
Amami Oshima Fortress Unit (See Units)
Amboina: 65; occupied 66; 185
America (See United States)
Ammunition: stockpile, 17
Anami, Gen., Korechika: 11
Andaman Is: orders to attack, 64; captured, 70; 71; 89; 113; 118; 144; 145; 183; 223
Andaman Sea: 118
Anshan: raided, 199
Aomori Prefecture: 179; 228
Arakan Mts: 132
Area Armies (See Armies)
Armament, Japanese: placed under military control 24-5; built up, 26-7
Armies, Area, Japanese
Burma: 113; 135; 160; 171; 187; 222; 224; 235; 253; 271
North China: 19; 94; 164; 166
Second: 76; to Davao, 155-6; 159; mission revised, 175-6; 177-8; 182; 185; 187; 223-4
Third: 314; 331
Fifth: 179; 195-6; 202; strengthened, 225; 231-2; 268-9; 285-7; 293; 297-8; 334
Sixth: 227-8; 309
Seventh: 182; 185; 223-4
Eighth: activated 108; 110-3; withdrawn from Guadalcanal and Buna, 119; 121; 123; 125; 128-9; 135; 148-50; 152; 156; isolated, 170; mission revised, 175-6; 184
Tenth: 216; 219; 259-60; 268-9; 273; 279; 287; 301-2; 327
Eleventh: 247; 268; 285-6; 316
Twelfth: 247; 268; 285-6; 316; 342
Thirteenth: 247; 268; 285-6; 316
Fourteenth: 199-200; 208; order of battle, 209; 215; 217; strengthened, 219; withdraws from Leyte, 210; 221; 223-4; 234-5; 252; 280
Fifteenth: 247; 268; 285-6; 316
Sixteenth: 247; 268; 285-6
Seventeenth: activated, 243; 268-70; 285-7; 293; 298-9; 315; 332; 334
British Army: in Burma, 69; retreated to India, 70; 212
British-Indian Army: 118; 132
National Army of Burma: 253
Central: 77; 81; 114 Chungking: 74; 118; 122-3; 132-4; 137; l4l; 242; 284; 306; 332
Nationalist, 1st: 148; 163; 239
War Sector, 1st: 164
War Sector, 6th: 164
War Sector, 9th: 164
5th: retreated north of Burma Kunming Road, 70
6th: retreated toward Cheli and Fohai, 70
66th: retreated north of Burma-Kunming Road, 70
Armies, Dutch: 67
Armies, French Indo-China: 134; 255; 271
Armies, General, Japanese
First (East): 248; 282; 285-7; 293-5; 317; 319; 340
Second (West): 248; 282; 285-7; 293-5; 319; 327; 340
Armies, Indian National: fn 1, 149
Armies, Imperial Japanese: 12; build-up, 15; conscription, 16; disposition of, 18-9; in China, 30; in Manchuria, 32; overall opns plan, 49; 54; 122; 145; in Burma, 201; in China, 242; 243; 255; in Manchuria, 330
Borneo Garrison: 185; renamed 37th Army, 223-4
China Expeditionary: 19; 45-9; 52; 54; orders to wage war, 59; 60; orders for China
Incident, 61; 76; 81; 92-4; 113-4; 116; 122; 137; 158; 163; 165-7; 196; 199; 202; 213; 216; 226-7; 233; 242; 260; 271-3; 279; 306-10; 316; 327; 332; 334-5
Formosa: 18; 47; 49; 180-2; 184; 196; 202-3; 209; 213; 215; redesignated Tenth Area Army, 216; 232
French Indo-China Garrison: 112; 168; 225
General Defense: 268
Homeland Defense: 268
Korea: 18; 159; 195; 219; 233; 273
Korea District: 315
Kwantung: 18; 30-2; 76; 116; 137; 166; 196; 215; 228; 233; 264; 270; 272-3; 298-9; 310-2; 314-6; 329-35
Kwantung Defense: 31; 61; 314; designated 44th Army, 331
Mechanized Army Hq: 76
Mongolian Garrison: 19; 166; 226
Northern: 32; 136-7; 159; 168; redesignated Fifth Area Army, 179
Southern: 19; order of battle, 43; 45-9; 51; 57; orders to wage war, 59-60; 64; recommends speed-up opns, 65; Burma Opn, 68-70; 74-6; defensive adjustments, 87-8; 91-3; 108; 112-3; 122; 135; 138; 149-50; 152; 156; 159-63; 165; 167; 171; 177-8; 182; change in mission, 183-8; 198; 200; 202-3; 213-4; 216; moves to Saigon, 221-2; 224-5; 231; 243; 250-6; 273; 279-81
Thailand Garrison: 122; 168
Tokyo Defense: 316-7
Wuchang-Hankou Defense: redesignated 34th Army, 226
1st: 19; 166; 226
2d: 156-7; 187-8
3d: 18; 31; 331
4th: 18; 31; 314; 331
5th: 18; 31; 331
6th: 18; 31; 263; 309
11th: 18; 94; 165-6; 199; 225-6; 332
12th: 18; 164; 166; 172; fn 4, 187; 226-7; 272
13th: 18; 94; 137; 166; 226; 308-9
14th: 19; 43; 45; 52; lands in Philippines, 64; reinforced, 65; 76; 100; fn 2, 155; 156; 158; re Italians, 167; 180; 182; 185; 187-8; reorganized into 14th Area Army, 208
15th: 19; 44; 52; crosses Burma-Thailand border, 63; Burma Opns, 68; occupies Rangoon, 69; occupies Mandalay, 70; 133; 135; 161-2; 170; 187; 221-2
16th: 19; 44-5; 51; reinforced, 65-6; occupies Java, 67; 104; 135; 156; 185
17th: ordered take Port Moresby, 97; reinforced, 99-100; on Guadalcanal, 101-10; 112
18th: 108; 112; 123-6; 129; 170; 175-8
19th: 135; 156
20th: 19; 227-8; 272
23d: 19; 45; 47; 52; 60; attacks Hong Kong, 63; 164-6; 226-7; 308
25th: 19; 44-5; 51; lands on Malaya, 62; 168; 185
27th: organized to defend Kuriles, 179; strengthened, 225
28th: 160; 222
29th: organized to defend
Malaya, 168; 185; 223-4
30th: activated, 331
31st: activated 153-4; 184; 187; order of battle, May 44, 189; 193
32d: to defend Nansei Is, 180-2; at Okinawa, 209; 215; 301-3; 327
33d: fn 3, 161; 187; 222; 253
34th: 226-7; 309; 314; 331-2
35th: activated, 208-9
40th: 259; 297
55th: 286; 316
58th: 286; 332
Armies, Red Chinese Yenan: 284
Soviet Army, Far Eastern: 32; 39; 239; 335
Soviet Army, in east: 30; 54; 65; 228; 298; 329; 332; 335
Armies, Thailand: 36
Armies, U.S.: 147; 199; 212; 241; 242; 252; 254-5; 298; 299; 303; 306; 308; 310; 335
U.S. Sixth: 234
Army Air Force, Japanese: ordered patrol Indian Ocean, 113; in East China Sea area, 274-5; 304; strength May 45, 305
Army Air Opns, Direction of: 273; 276
Army Air strength: Mar 45, 277
Army General Staff: 2-4; responsibilities, 5; 7; 9-10; 13; 23; 31; 48-9; issues orders for war, 59-60; orders for China incident, 61; desires conquest of Burma, 68; issues orders Burma Opn, 69; 75; opposes occupation of Australia, 82-3; 85; 92; 98; orders 17th Army reinforced, 99-100; 104; 106; 109; 111-2; 117; plan for Southwest Area, 131; strengthens Northeast Area, 136-8, 145; 149; 157-61; 166; re Italians, 167; 175-9; reinforces Formosa and Nansei Is, 179-85; 188; 192-4; plans to strengthen Japan's defenses, 195-9; 214-5; 219; 222; 225; 228-33; 259; 264; 266; 270; 272; 283; 287; 290; 298; 301-4; 313; 327; 331-2; 337; 339-40; accepts Emperor's decision, 341
Army-Navy Central Agreements: re Southern Area. 89; 25 Mar 43, 128; 25 Mar 44, 153; revised, 223; on air opns, 204; 218; 273; to strengthen coastal areas of Japan, 308; re KETSU-GO Opn, 321
Army Operational Supplies: 20
Aroe Island: 117; 156; 176
Asia: fn 26, 112; 238
Astoria, U.S. cruiser: sunk, fn 21, 99
Attu: 85-6; landing, 87; 115; 122; 136; 155
Australia: troops in, 36, air strength in, 37; Allied naval strength near, 38; 40; est strength in, 78; 80; 82; 88-9; 96; 107; 143-4; 183
Banda Sea: 132; 135; 144-6; 152
Bandon: Japanese troops land at, 62
Bandjermasin: occupied, 66
Bangkok: 61; occupied, 62
Bataan Pen: 64; falls, 65
Batan Is: 181
Batavia: 67; 90
Bay of Bengal: 71; 118; 159; 161
Bene Bena: 127; 129
Berlin: fn 1, 149
Bhamo: occupied, 70
Biak Is: 170; 177-8; 192
Bismarck Archipelago: 50; plans to capture, 52-3; proposed military admin of, 56; 119; 176; 184
Bombay: Allied naval strength near, 38
Bonin Is: (See Ogasawara Is)
Borneo: 34; enemy troops in, 35; 50; proposed military admin of, 56; 65; Japanese troops land, 66; 90-1; 185; 223-4
Bose Chandra: fn 1, 149
Bougainville Is: 120-1; 123; 129-30; 147
Brigade, Amphibious, Japanese 1st: 152-3; 190
Brigade, Cav, Japanese 3d: 264; 313
Brigades, Ind Mixed, Japanese
21st: 44; 112
Brigades, Inf, Japanese
35th: 100; 102; 108
65th: 43; 64; 131
68th: 228; 259
Brigades, Tank, Japanese
Brisbane (Australia): 144
Britain (See Great Britain)
British Army (See Armies)
British-Indian Army (See Armies)
British Malaya (See Malaya)
British Fleet (See Fleets)
Buka Is: 120
Buna: 97; 111; 117; 119-21; 127; 138
Burma: 34; troops in, 35; air force in, 37; 48; 50-2; proposed military admin of, 56; Japanese troops cross border, 63; opns agst, 68, enemy strength before war, 68; opns in, 69-71; 74-5; 88; air bases strengthened, 91; 118; 121; 122; 131-3; 135-6; 144-5; 148; 160-2; 170; 173-4; 183; 185; 188; 198; 201; 212; 221-2; 224; 230; 235; 253-4; 271
Burma Area Army (See Area Armies)
Burma Road: 160
Burma-Japan Alliance Pact: 149
Buthidaung: 132; 135; 148
Cairo Conference: 148
Camranh Bay: 66
Canada: est strength in, 79; 80
Canberra, Australian cruiser: sunk, fn 21, 99
Canton: troops stationed in, 19; 53; 64; 164; 226; 242; 310
Canton-Hankou Ry Penetrating Opn (See Operations)
Cape Esperance: 99
Cape Hollman: 126
Caroline Islands: 145-6; 150-1; 154; 176; 191-2
Cavutu Is: 72
Celebes: 50; proposed military admin of, 56; 71; 223-4
Central Agreements: 3; 149-51
Central Army (See Armies, Chinese)
Central Army Command (See Commands, Japanese)
Central Authorities: fn 2, 3
Central Military District (SeeMilitary Districts)
Central Pacific Area: 101; 130; Allied strength 142; 145; 147; strategy, 149-53; Army-Navy Central Agreement on, 153; transportation in, 154-5; 158; 172; to be reinforced, 175; 183; directives, 1B8-90; 191-2; 205; 221; 243; opns in, 256-7
Central Pacific Islands: 144
Central Shipping Transport Hq: 45
Ceylon: 70-1; 77; 79; plans to invade, 96; 144
Changchun: troops at, 18; air units at, 21
Changsha: 136; 226-7
Chekiang-Kiangsi Opn (See Operations)
Chekiang Province: 93-4; 113; 199; 327
Chiang Kai-shek: 41
Chicago, U.S. cruiser: damaged, fn 21, 99
Chichijima Fortress Unit (See Units)
Chichijima Garrison Unit (See Units)
Chihsi: troops at, 18
China: 12-4; 17; 21; 23; 27; British naval strength near, 38; 41-3; 46-7; 49; 54-5; 58; 60; 68; blockade agst to be strengthened, 69; 75; 77; 81; 88-9; 93-4; 107; fn 26, 112; 114; 116; 122-3; 136-7; 141; 145; 148; 156; 160; 162-3; 166-8; 171; 174; 177; 183; 198; 200; SHO-GO air strength, 206-7; 222; 226; 228-30; 232-3; 237-40; 242-5; 251; 254; 259-62; Japanese strength in, 263; 266; 271-2; 274-5; 277; 284; 304; air strength in May 45, 305-11; 313-4; 318; 324; 331-4
China-Burma border: strategic points occupied, 70
China Expeditionary Army (See Armies)
China Incident: 7; 12; 14; 22-3; 25; 27; 30; 61; 74; 81; 114; 265
China-Japan Alliance Pact: 149
China Theater: 241; 271; reorganization of forces, 306
Chinan (Licheng): troops at, 19
Chindwin River: 170
Christmas Is: 89
Chugoku Military District (See Military Districts)
Chumphon: Japanese troops land at, 62
Chunking: 81; 88; 136; 141
Chungking Army (See Armies, Chinese)
Chungking Govt: 54; 56; 77; 81; 114; 163; 183; 306-7
Chungking Operation (See Operations)
Civil Defense Plan: established, 245-7
Clark Field: 252
Coco Is: 77
Colombo: naval strength near, 38; 71
Combined Fleet (See Fleets, Japanese)
Command Organization: Japanese military, Chapter 1
Central Army: 18; 195
Eastern Army: 18; 195
General Defense: 18; 47-9; 179-80; 195-6; 202-4; 229; 248; 264; 269-70; 272-3; 279; inactivated 287
Kwantung Defense: 18
Manila Defense: 215
Northern Army: 18; 115
Shipping Transportation: 92
Singapore Defense: 224
Western Army: 18; 45; 182; 195; 209
Communication System: 291
Concurrent Affairs: 4-5
Constitution, Japanese: 1-2; 8
Coral Sea: 73
Coral Sea Battle: 72; 83; 97
Corregidor: 64; captured, 65
Council in Presence of Emperor: 146; 339
Dairen: raided, 199
Daito Is: 181
Davao: 90; 155-6
DeGaulle, Gen., Charles: 254
Expeditionary, 1st thru 8th: 153
Ichiki: 84; ordered to occupy Midway, 85; to Truk, 99-100; ordered to retake Guadalcanal, 101-5
Ito: ordered seized Amboina, 65; occupied Amboina, 66
Kawaguchi: lands British Borneo, 66; 102-5
Munition Transport Control: 116
North Seas: 84; ordered occupy Aleutians, 85; inactivated 115
Sakaguchi: captured Bandjermasin, 66 South Pacific, 1st thru 6th: 152-3
South Seas: 19; order of battle, 44-7; 52-3; 60; occupies Guam, Wake and Rabaul, 63-4; ordered attack New Guinea, 64; 72-3; to land at Buna, 97-8; 100; 106-8
South Seas, 1st: 190
South Seas, 2d: 190
South Seas, 4th: 189
Toho (Ito renamed) captured Koepang: 66
Diet: 1; 3
Dili: captured, 66
District Army Hq: 245
Divisional Districts: 246
Divisions, Antiaircraft, Japanese 1st: 317
Divisions, Depot, Japanese:
Divisions, Imperial Guards: 19; 44; 61-2; 75; 317
Divisions, Imperial Guards
1st Hq: 1
2d Hq: 342
Divisions, Minelaying, Japanese 19th: 72
Divisions, Tank, Japanese
1st: 76; 248; 295; 313
2d: 76; 208-9; 228; 263
3d: 76; 166; 332
Divisions, Inf, Japanese
1st: 18; 31; to Philippines, 215; 228; 263
2d: 19; 44; assembled Camranh Bay, 66; 75; 104; 106; 108; to the Philippines, 127; 160; to Thailand, 254
3d: 19; 227; 310
4th: 19; 64; 75-6; 168; to Thailand, 254
5th: 19; 44; 75; 113; 135; 156
7th: 18; 137; 225
8th: 18; 31; 208-9; 228; 263
9th: 18; 31; to Formosa, 259; 263
10th: 18; 31; 209; to Philippines, 219; 228; 259; 263
11th: 18; 31; 248;295; 313
12th: 18; 31; 228;263
13th: 19; 227; 310
14th: 18; 31; 156;188-9; 259
15th: 19; crossed Burma-Thailand border, 63; 160; fn 3, 161; 170
16th: 19; 43; lands Lamon Bay, 64; 75
17th: 19; 137
18th: 19; 44; lands Rangoon, 69; 148; 160; fn 3, 161; 171; 187
19th: 18; in Korea, 32; to Philippines, 219; 228
20th: 18; 112; 127
21st: 19; 44; 64; 168
22d: 19; 166; 225; 227; 254; 308
23d: 18; 31; 215; to Philippines, 219; 228; 259; 263
24th: 18; 31; 209; 263; 303
25th: 18; 31; 248; 295; 313
26th: 19; 208-9
27th: 19; 137; to China, 166; 227; 310
28th: 18; 31; 181; 263
29th: 18; 31; to Saipan, 152; to Guam, 153; 189-90; 263
31st: 135; 160; fn 3, 161; 170
32d: 19; to Pacific area 166; 187
33d: 19; 68; occupied Rangoon and Prome, 69; 75; 160; fn 3, 161; 162; 170
34th: 19; 227; 310
35th: 19; to Pacific area, 166; 177-8; 187; remains on Leyte, 220
36th: 19; 156; 204
37th: 19; 166; 225; 254; 308
38th: 19; 45; 47; 60; 65; occupied Palembang, 67; 108
39th: 19; 166; 227; 310; 332
40th: 19; 227
41st: 19; 112; 127
43d: 189; 198
46th: 156; to S'pore, 254
47th: 204; 209; 228
48th: 19; 43; 45; lands Lingayen Gulf, 64; assembled Jolo, 66; on Timor, 135; 156
49th: 188; 224
51st: 19; 31; 42; 108; 112; 123; 125-6; 129 52d: 18; 76; 152; Truk, 153; 189
53d: 18; 160; fn 3, 161; to Burma, 171; 224
54th: 18; 135-6; 160
55th: 19; 44; 68; occupied Rangoon, 69; 132; 135; 148; 160
56th: 19; 44; 45; occupied Toungoo, 69; 160; fn 3, 161; 187; 198
57th: 18; 31; 248; 295; 313
59th: 310; 332
62d: 166; 209
63d: 310; 332
77th: 225; 297
79th: 261; 315
94th: activated, 224
100th: organized, 188
102d: organized, 188
103d: organized, 188; 209
104th: 19; 227
105th: organized, 188; 209
109th: 189; 194; 256
110th: 19; 166
111th: 228; 248; 313
116th: 19; 166; 227
120th: 228; 248; 313
121st: 248; 313
125th: 313; 314
147th: 247; 297
Dorsetshire, British heavy cruiser: sunk, 71
Dutch Army (See Armies)
Dutch-Australian Forces: 212
Dutch East Indies (See Netherlands East Indies)
Dutch Harbor (Aleutians): 144
Dutch Timor (See Timor)
East China Sea: 242; 260; 268; 273-6; 278
East Coast Military District (See Military Districts)
Eastern Army Command (See Commands, Japanese)
Eastern Military District (See Military Districts)
Economic Blockade: preparations agst, 33
Emperor: 1-4; 6-7; 9-11; 57; 338; decision to end war, 339-40; broadcasts decision, 341-3
Enterprise, U.S. aircraft carrier: damaged, 103
Europe: 4l; 119; 142-3; Allies land on 2d front, 172; 174; 235-6; 306
Expeditionary Detachments (See Detachments)
Fiji Is: 77; est enemy strength in, 78; 82-4; opn agst cancelled, 87; 96-7
Finchhafen: 126; 129; 147
Fleet, British: 63; in Indian Ocean, 70; 143
Central Pacific: 154
Combined: 45; 51; 57; 70; 72; insists Midway be occupied, 83-4; 86-7; orders capture of Makin, 101; orders attack on enemy carrier task force near Solomons, 102-3; 105; 110; 119; 200; 217; 231-2; 294-5; 300; 302-4; 325
Mobile, 1st: off Marianas, 171; 191; 193
Southern Expeditionary 1st: 67
2d: 65; 85; advanced to north of Solomons, 102-3; 105; 109
3d: attacks enemy off Soerabaja, 67; advanced to north of Solomons, 102-3; 105
4th: 52; 72; prepared to attack Port Moresby, 73; occupies Makin, 101; 131; 152; 325
5th: 85; 115
8th: at Rabaul, 98-100; 105
Fleet, U.S.: at Pearl Harbor, 61; fn 25, 109; approaching Leyte, 200
Flores Is: 254
Flores Sea: 152
Formosa: training program, 23; 42-3; 46; 53; supply base, 53; 91; 158-9; 172-5; directives, 179-82; attacked, 199-200; 202-5; SHO-GO air strength, 206-7; 212; 225; 228; 237-8; 242; 256; 259-60; 266; 274; 277-8; 299; 301; 304; air strength in May 45, 305; 307; 313; 326-7
Formosa Army (See Armies)
Formosa Military District (See Military Districts)
France: Allies establish 2d front, 235
Free India Provisional Govt: fn 1, 149
French Indo-China: 19; 23; 33; 42-3; 46-7; 49; 50-1; main supply base, 53; 62; 64; 88; air bases strengthened, 91; fn 26, 112; 134; 137; 158; 160; 163; re Italians. 167-8; 174; 183; 185; 225; 243; 250-1; 253-6; 271; 277; 309
French Indo-China Army (See Armies)
French Indo-China, Gov Gen: 254; refuses Japanese demands, 255
Fuchou: 199; 226
Fuchun Chiang: 94
Fuel, aviation: stockpile, 17; 27
Fu Ho: 94
Fukien Province: 327
Fukuoka: troops at, 18; 247; 268
Funafuchi Fortress Unit (See Units, Japanese)
Geelvink Bay: 176-8; 192
General Army Headquarters (See Armies, General, Japanese)
General Defense Command (See Commands, Japanese)
Germany: 12; 26; 31; 40-1; 119; 144; 146; 235-6; 238; capitulates, 310
German-Soviet war: 30-4; 41
Gilbert Islands: 100; 130-1; 146; 152; 173
Government of Free India, Establishment of: 149
Great Britain: 12; 23; placed embargo on oil, 29; 30; 33; strength in sth, 34-8; air force in Malaya, 34; naval strength in sth, 38-9; 41; 45; 47; 49; 54-5; 57-9; est strength, 79-80; 140; 148
Greater East Asia War: 88
Greater Khingan Range: 311
Group, Cav: 19
Guadalcanal: 96; enemy lands, 98-106; 108-11; 117-20; units withdrawn from, 121; 123; 127-8; 138; 155
Guam: troops in, 36; 48; 50; plans to capture, 52; proposed military administration of, 56; 60; occupied, 63; 100; 189; 193; 198; 221
Guard Districts: 246
Hagen: 127; 129
Hainan Is: 43; 46; fn 26, 112; 277; 308
Halmahera Is: 138; 152; 158; 177-8; 185; 187; 192
Hamamatsu: incendiary bombings of, 282
Hankou: troops at, 19; 54; 314
Hanoi: air units at, 21; 255
Hara, Yoshimichi: 11
Hata, Field Marshal, Shunroku (2d Gen Army Cmdr): 339
Hatanaka, Maj., Kenji: 341-2
Hattori, Col., Takushiro: fn 19, 98
Hawaii: Allied naval strength near, 38; 46; Japanese Fleet attacks, 61; est enemy strength in, 78; 143-4
Hawaiian Sea: 46
Heito: air units at, 21
Hengyang: 198; 226-7
Hiranuma, Baron, Kiichiro: 11
Hiroshima: atomic bomb dropped on, 337
Hitokappu Bay: 46
Hokkaido: 116; 136; placed on wartime footing, 137; 178; 195; 203-4; SHO-GO air strength, 207; 242; 247; 297-8; air strength in May 45, 305; 325
Hollandia: 170; 176; enemy lands, 177
Homeland (See Japan)
Hong Kong: troops in, 35; air force in, 37; naval strength near, 38; 45; 47; 50; plans to capture, 52; proposed military administration of, 56; 60; surrenders, 63; 66; 91; 237
Hong Kong, Gov Gen of: instructions re Italians, 167; 228
Hong Kong Operation (See Operations)
Honshu: 179; 204; 242; 247
Horii, Maj. Gen., Tomitaro: 44
Houston, U.S. cruiser: sunk, 67
Hoyo Fortress Unit (See Units)
Hozumi, Maj., Matsutoshi: 84
Hsiang Chiang: 271
Huang Ho: 164; 307
Hukawng River Valley: 148; 171; 187
Hulun: troops at, 18
Hunan-Kwangsi Operation (See Operations)
Hunan-Kwangsi Sector: 164
Hunan Province: 239; 310; 332-3
Iceland: est enemy strength in, 79
Ichang: 81; 307
ICHI-GO Operation (See Operations)
Ichiki, Col., Kiyonao: 84
Ichiki Detachment (See Detachments)
Imoto, Col.: fn 19, 98
Imperial Conference: 9-10; 39; 43; decides on war, 57-9; 141; to end war, 339
Imperial General Headquarters: established, 7; 33-4; 43; 45-7; 49; 52; 55-7; 64-5; orders Lae, Salamaua and Port Moresby captured, 72-3; 75-7; 81-3; 85-9; orders air bases strengthened, 91-2; orders Chinese air bases destroyed, 93-7; orders Guadalcanal retaken, 101; 103; reviews situation Oct 42, 107-8; activates 8th Area Army, 108; 111-4; 119; 122-3; 127; 129-31; 140; enemy situation Sep 43, 141; 145-6; 152-5; 157; 162-3; 165; 182-3; 190-1; 194-5; 200; 202; 204; 209; plan for island defense, 210-3; orders SHO-GO No. 1, 215-6; 218; 221; 223; 226-7; 230; 232; 234; 236-8; est manpower requirement. 239; operational plan, Jan 45, 241-5; revises Southern Army's orders, 250-1; 259; 268; 271; 281; 284; 285; revises command system, 286; 291-2; 306; 308; 310-1; 314-5; 319; 322; 330; 333; 335; 337; 340; issues orders suspending opns, 342; issues orders to cease hostilities, 343
Imperial General Headquarters Army Orders
No. 556: 46
No. 557: 47
No. 558: 47
No. 564: 48
No. 569 thru 574: App No. 1
No. 626: 85
No. 628: 85
No. 1081: 202
No. 1245: 269
No. 1299: 287
No. 1339: 298
Imperial General Headquarters Directive No. 991: 47
Imperial General Headquarters Navy Order No. 1: 45
Imperial Japanese Army (See Armies)
Imperial Palace: 196; 317; 338; 342
Imperial Rescript: 341-2
Imphal: 118; 161-2; 170; 221
Imphal Basin: 161
Imphal Operation (See Operations)
India: troops in, 36; air strength in, 37; 40; 77; est enemy strength in, 79-80; 88-9; 113; 118; 131; 133; 162; 183; 222
India Independence Movement: fn 1, 149
India National Army (See Armies)
Indian Ocean: 40; 70; 72; 84; 89; 96; 107; 113; 143; 173; 212; 230; 274
Indo-Burma border: 113; 122
Indo-China (See French Indo-China)
Industries, National Defense: expansion of, 24
Inland Sea: 319
Inner South Seas: 46
Inspectorate General for Army Aviation: 210
Inspectorate General for Army Training: 3-5; 340
Inspectorate Office of Supply (Kwantung Army): 116
Ireland, Northern: est enemy strength in, 79
Irrawaddy River: 132; 222; 235; 253; 271
Ise: 228; 295
Ishihara, Maj., Sadakichi: 341-2
Ishiwata, Sotaro: 11
Island Defense: 210
Italy: 40-l; 140; 144; surrenders, 148; 167
Ito Detachment (See Detachments)
Iwo Jima: 237; 256; 258; 274; 282; 296; 318-9; 323
Izu Islands: strengthened, 209
Japan: 2; 12; peacetime strength, 13; 21; 25; 31; 33; 39-42; 46; 54-5; 58-9; 61; 68; 75; 81; 87; 89; 92; bombed, 93; 96; fn 26, 112; 114; 116; 119; 135; 137-41; l44-5; 149; 152; 156; 158; 160; 162; defenses strengthened, 168; 173-4; 179-81; 188-91; 194; Plans to strengthen defenses of, 195-7; raided, 199; 200-3; 205; SHO-GO air strength, 206-7; 211-2; 228-30; 232-3; 235-44; 248-52; 255; 259; 262-6; 269-70; 272; 275; 277-85; 287-8; 294-7; 306; 310-1; 313; defense of, 316; 318; 320; 323; 325-9; 333-6; 338-40
Japanese Govt: 33; 140
Japanese Thailand Military Alliance Agreement: 62
Japan Sea: 290; 297; 319; 328 Java: 50; proposed military administration of, 56; 65-6; occupied, 67; 77; 88; 90; air bases strengthened, 91; 113; 134-6; 173; 185; 223-4; 326
Java Operation (See Operations)
Java Sea Battle: 67
Jolo: 66; 252
Kagamigahara: air units at, 21
Kagoshima: 203; 295; 327
Kaitak Airfield: attacked, 63
Kanto: 242; 265-6; 269; 281; bombed, 282; 284; 287-8; 297; 318; 322; 324-5
Karafuto (Sakhalin): 239; 242; 247; 297
Kawaguchi Detachment (See Detachments)
Kawaguchi, Maj. Gen., Kiyotake: 102
Kaya, Okinobu: 11
Kerama Is: 299; 301
KETSU-GO Operation (See Operations)
Kiangsi Province: 93; 310
Kinki: bombed, 281
Kiska: 85-6; landing accomplished, 87; 122; 136; 155
Kobe: 196; 242; 246; 269
Koepang: captured, 66
Koga, Maj., Hisashi: 341-2
Koiso Cabinet: 11; 201
Koiso, Gen., Kuniaki: 11
Kokoda: 97; 104
Kokura: raided, 172; 196
Kondo, Vice Adm., Nobutake (Cmdr, So Force): 70; 71
3d: 11; 26
Konoye, Prince, Ayamaro: 11
Korea: 32; 42; 116; 153; 160; defenses strengthened, 168; 187; raided, 199; 228; 239; 242-3; 247-9; 260-1; 264; 266; 269-70; 272; 274; 285; 295; 298-9; air strength in May 45, 305; 209-13; 315-6; 322; 330-5; 340
Korea Army (See Armies)
Korea District Army (See Armies)
Korea Military District (See Military Districts)
Korean Channel: 284
Korea Straits: 287; 321; 328
Kota Bharu: Japanese troops land at, 62
Kowloon Pen: 52
Kuangchou Bay: 123; 137
Kuantan: Japanese troops occupy, 63
Kume Unit (See Units)
Kumusi River: 107
Kurile Fortress Inf Unit (See Units) Kurile Islands: 115; 137; 144; 159; 168; 172-3; 178; 202-3; 242; 247; 297-8 Kuril Islands Garrison Unit (See Units)
Kwangsi Province: 239; 310; 332-3
Kwantung Army (See Armies)
Kwantung Army Field Ry Unit (See Units)
Kwantung Defense Army (See Armies)
Kwantung Defense Command (See Commands)
Kweichow Province: 306
Kweilin: 162-5; 199; 226; 332
Kyushu: 116; 159; raided, 172; 199; 228-9; 235; 242; 247; 260; 265-6; 269; 274; bombed, 281-2; 284; 287-8; 296-7; 299; 300-1; 304; 319; 321-2; 324-5; 336-7
Kyushu Operation (See Operations)
Lae: 72; 111; 117; 120-1; 123-5; 127; 129-30
Lameng: garrison overcome, 198
Lamon Bay: Japanese troops landed, 64
Landing Force (Japanese), Yokosuka, 5th Spec: 101
Langson: 165; 252
Laohokou: 272; 307
Lashio: occupied 70
Lesser Khingan Range: 312
Lesser Sunda Is: proposed military admin of, 56; 90; 156
Leyte: 199; 200; 215; enemy lands on, 216-7; 219: Japanese forces withdrawn, 220
liaison Committee: 7
Liaison Conference: 7-9; members of, 11, 33, 39; plan for war, 40-1; decided date for war, 57
Licheng (Chinen): troops at, 19
Linchuan Mts: 95
Lines of Communications: 53; air lines estab in So Area, 91; logistical support Jun 42, 92-3; logistical problems, 43; 138-9; logistical support Mar-Jun 44, 197; 265-6; 288-9; 336-7
Lines of Communications, Burma Area Army: Inspectorate Sect, 188
Lines of Communications, Second Area Army: Inspectorate Sect, 188
Lines of Communications, Southern Army: Inspectorate Sect, 188
Lingayen Gulf: Japanese troops land at, 64; U.S. forces land, 234; 252
Local Defense Units: 246
Logistical Support (See Lines of Communication)
Lombok Strait: 156
Louisiade Archipelago: 73; 106
Lu Chiang: 165
Luichow Pen: 122; 137; 198; 226
Lunga River: 105
Luzon: attacked, 64; 199; 200; 213; 216; 220; 235; 237; 251-2
MacArthur, Gen., Douglas: 191; 343
Machinato Port: 302
Madagascar: est enemy strength in, 79
Madang: 111; 120-1; 127; 129
Makassar: occupied, 66; 152
Makassar Strait: 156
Makin Atoll: enemy surprise landing on. 100; 4th Fleet occupies, 101; 147
Malaya: 34; troops in, 35; air force in, 37; 48; 50-3; proposed military admin of, 56; 58-60; Japanese land on, 62; advance, 63; occupy, 70; 75; 88; 91; fn 26, 112; 134; fn 1, 149; 158; 160; 168; 171; 173; 183; 185; 225; 243; 251; 253-4; 271
Malaya Operation (See Operations)
Malay Force (Navy): 71
Malay Pen (See Malaya)
Manchukuo (See Manchuria)
Manchuria: 12-4; 17; 21; 25; 30; defenses strengthened, 31; 34; 4 42; 54; 61; 65; 75-7; fn 26, 112; 114; 116; 137; 145; 152-3; 155-6; 160; 166-7; 181; 186; 188; raided, 199; 208; 215; 227-9; 232; 235; 239-40; 244-5; 248-9; 259; 261-4; 266; 272; 275; 298; 304; air strength in May 45, 305; 309-16; 324; 329-35; 337
Manchurian Incident: 12-3; 22; 24; 329
Mandalay: occupied, 70; 132; 235
Manila: occupied, 64; 66; 96; 185-6; 213; 215; 252; 343
Manila Defense Command (See Commands)
Manokwari: 152; 177-8; 185
Manpower and Matériel: Oct 44, 239-41
Maranikau River: 105
Marcus Is: 130; 144
Mariana Is: 146; 150-1; 154; 171-2; 174; 179; 189-93; 197; 200-1; 221; 230; 235; 256; 299; 318; 321; 323
Marianas Operation (See Operations)
Marine Corps, U.S.: lands in Solomons, 98
Marine Division, U.S., 1st: fn 22, 99
Maritime Territory: 329
Marshall Is: 46; 131; 146-7; 173; 175; 190
Marshals and Fleet Admirals, Board of: 3
Materials Mobilization Plan: 55
Mechanized Army Headquarters (See Armies)
Mediterranean Sea: Allied naval strength in, 38
Meiji, Emperor: 1
Midway: est enemy strength in, 78; 83; forces to be used agst, 84; order to occupy, 85-6
Midway, Battle of: 86-7; 97
Midway Operation (See Operations)
Mikawa, Vice Adm. (Cmdr, 8th Fleet): 99
Military Administration in occupied areas: 55
Central: 268; 285-6; 293; 320
East Coast: 268; 285-6; 293
Eastern: 268, 285-6; 293; 320
Formosa: 268-9; 297
Korea: 268-9; 285-6; 298-9
Northeastern: 268; 285-6; 293
Northern: 268-9; 285-6; 297
Western: 268; 285-6; 293; 320
Military Order No. 1: 5-6
Milne Bay: 104
Mindanao: 187; 200; 252
Mindoro: enemy lands at, 220
Ministry of Munitions: 149
Miri: oilfields, airfield occupied, 66
Misima Is: 73
Mito Army Air Signal School: demonstrate agst surrender, 342
1st Gp Opnal Army: 247
2d Gp Opnal Army: 248
3d Gp Opnal Army: 248-9
Mobilization Schedule: 247-50
Moji: raided, 172
Moluccas: 50; proposed military admin of, 56; 138
Mongolia, Inner: 332
Mongolian Garrison Army (See Armies)
Moresby (See Port Moresby)
Mori, Lt. Gen., Takeshi (1st IGD Cmdr): killed, 341
Morotai: 198; 211-2
Moulmein: occupied, 63; 69
Moulmein-Pegu Road: 69
Mt Suribachi: 257
Mukden: raided, 199; 314; 331
Munda: 121; enemy bombs, 128; enemy occupies, 129; 138; 147
Munition Transport Control Detachment (See Detachments)
Musi River: 67
Mutanchiang: troops at, 18; air units at, 21; 312; 335
Myitkyina: occupied 70; 132; garrison overcome, 198
Nagano, Fleet Adm., Osami: 11; 71; 339
Nagasaki: atomic bomb dropped on, 337-8
Nagoya: 196; 229; 246-7; 268; bombed, 282
Nagumo, Vice Adm.: committed suicide, 194
Nakgusiku Bay Portress Unit (See Units)
Nakhon: Japanese troops land at, 62
Nanching: troops at, 19; air units at, 21; 308
Nansei Is: 175; directives 179-82; 202-5; SHO-GO air strength, 207; 212; 233; 237-8; 242; 256; 259-60; 266; 274; 277; 278-9; 299-300; 307; 313; 327
National Defense Industries (See Industries)
National Mobilization Law: enacted, 25
Naul Is: 101
Nauru Is: 144
Naval Air strength, Mar 45: 278
Navy Administration Area: 93
Navy Air Force, Japanese: disposition of, 325
Navy Air Forces: in East China Sea area, 274-5; 279
Navy General Staff: 2-4; 7; 9; 10; 46; recommends occupation of Australia, 82-3; 217; 230-1; 303; 339-40; accepts Emperor's decision, 34l
Navy in Indian Ocean (See Operations)
Navy, Japanese: 48; 50; 60; 64; 70-2; 76; 83; 88-90; cooperate Chekiang-Kiangsi Opn, 94; at Guadalcanal, 98; strength for Solomons Opn, 100; 106; 109-11; 118; at Rabaul, 125; 137; 145; 150-1; 154; losses off Marianas, 171; 179; cooperates defense of Formosa and Nansei area, 180; 191; 193-4; 200; 218; 285; 287; 289; 307; 320
Navy Minister: 2-4; 6-7; 10
Near East: est enemy strength in, 79
Negros: 252 Nemuro: 159
Netherlands: 12; 26; placed embargo on oil; 29-30; economic blockade, 33; strength in south, 34-8; 40; 45; 47; 49; 55; 57-9
Netherlands East Indies: strength in, 34-8; 48; 51; 59; 65; occupied, 70; 90; 117; 183
New Britain: 53; 147
New Caledonia: 77; est enemy
strength in, 78; 82-4; opn agst cancelled, 87; 96-7
New Georgia: 119-20; enemy lands on, 128
New Guinea: proposed military administration of, 56; 64; 77-8; 82; 97; 100; 104; 106-8; 110; 117-21; 123; 125-6; 129; 135; 138; 146-7; 150; 152; 156; 159; 170; 173-8; 183-4; 230
New Guinea Operation (See Operations)
New Zealand: troops in, 36; air strength in, 37; Allied naval strength near, 38; est enemy strength in, 78-9; 82
NICHI-GO Operation (See Operations)
Nicobar Is: occupied, 70; 89; 113; 144-5; 183; 223
North China Area Army (See Area Armies)
Northeastern Area: 107; 122; 136; Allied strength in, 142; directives, 178-9; 205; SHO-GO Army air strength, 206; 212; 230; 274
Northeastern Military District (See Military Districts)
Northern Area: 297
Northern Army (See Armies)
Northern Army Command (See Commands)
Northern Pacific Area: 183
North of Australia Area: 117; 121; strategy, 149-53; opns in, 155-7; 170; 173-4; directives, 175; 182-5; 188; 191; 205; 212; 223-4
Ocean Is: 101
Ogasawara Is (Bonin): troops at, 19; 43; 48; 154; 189-90; 194; 203; strengthened. 209; 211; 221; 237; 258; 274
Oikawa, Adm., Koshiro: 11
Oil: lack of, 26; stockpile, 28; requirements, 28; embargo plated on, 29; 33
Okabe Detachment (See Detachments)
Okinawa: attacked, 199; 225; 238; 259-60; 273; 281; 296; 299; 301-4; 310; 314; 319; 323; 327-8
Okinawa Campaign: (Allied) 284; 298; 301; 304
Operational Preparations: 10th, 180; 11th, 188
A-GO (Marianas): 190-4
Aleutians: plans, 82-5; progress of, 86-7
Burma: 68-70; outline orders for, 69; 133; 185; 253
Canton-Hankou Ry Penetrating: 226
Guadalcanal: 98-107; 127
Hong Kong: 45; 65 Hunan-Kwangsi: 164; 167; begun, 172; 198; 202; 226-7; 306
ICHI-GO: (China) Directives for, 162-7; 172; 198; completed, 226; 233
Java: plans for, 65; completed, 67-8
KETSU-GO: (Japan) situation prior to, 234; plans for 272; preparations for, 283-7; 289-91; movement of land forces, 293; 296; 304; 317; 321
Leyte: 218; troops withdrawn, 220; 237; 250
Malaya: 51; 53
Midway: plans 82-5; progress of, 86-7
Navy in Indian Ocean: 70-2
New Guinea: 104; 126
NICHI-GO: (Transportation) 328
Peiping-Hankou: 164; 167; completed, 172
Philippines: 45; 53
Port Moresby: planned, 72; suspended, 73; 106
Rabaul Area: 144
SEI-GO: (Air) 320
SHO-GO: preparations for and development of, 200-11; army air strength, 206; navy air strength, 207
SHO-GO No. 1: (Philippines) 200; 203-4; adjustment in strength, 208; preliminary actions leading to, 211-5; conduct of, 215-21; 231
SHO-GO No. 2: (Japan and Philippines) 203-4; adjustment of strength, 209 SHO-GO No. 3: (Japan) 203-4; adjustment in strength, 209
SHO-GO No. 4: (Northeastern Area) 203-4
Solomons: 104; 110
Southeast Area: plans, 82-5; Nov-Dec 42, 108-12 Southern: 39; development of plan, 42; orders of battle for 43; 54; 65; 68; 72-3; 77; 161; 172
TEN-GO: (Air) 276; 300
U-GO: (Burma) 160-2; 170; 187; 198; 201
Osaka: troops at, 18; 196; 229; 242; 246-7; 268-9
Owen Stanley Range: 106-7; 120
Ozawa, Vice Adm.: (CinC, Combined Fleet) 303
Pacific Ocean: 230; Allies advance in, 283
Pacific Theater: 142; 148; 166: 241; 263; 306; 313; 330; 336
Pacific War (See World War II)
Palau: 42-3; 53; 60; 115; 128; 157; Allies attack, 171; 184-5; 188-90; 192-3; 259
Palembang: occupied, 67; 132; 134; 326
Panama: est enemy strength in, 78
Papua Gulf: 106
Paramushir Is: 122
Pearl Harbor: 58; Japanese Fleet attacks, 61
Peian: troops at, 18
Peiping: troops at, 19
Peiping-Hankou Operation (See Operations)
Peleliu Is: 198; 211-2; 259
Perth (Australia): 144
Perth, Australian cruiser: sunk, 67
Phibun, Prime Minister of Thailand: signs Japanese-Thailand Military Agreement, 62
Philippines: troops in, 36; air force in, 37; naval strength near, 38-9; 50-2; proposed military administration of, 56; 59; attacked, 64; U.S. forces surrender in, 65; 75-6; 91; 93; guerrillas in, 113; 117; 127; 131; 134; 139; 144; 150; 158; 168; 172-5; 179; 182-8; 191; 193; 200; 202-5; SHO-GO air strength, 206-8; 211-8; 220-4; 228; 232-3; U.S. forces land, 234-5; 237; 241; 243; 251-2; 259; 265; 271; 274; 280-1
Philippines, Battle of: 200
Philippines, Campaign: 300
Philippines-Japan Alliance Pact: 149
Philippines, Operation (See Operations)
Philippines Republic: Declaration of Independent of, 149
Philippines Sea Battle: 191
Phnom Penh: air units at, 21; 62; 326
Phuquoc Is: 61
Imperial Army-Navy Operational Plan, Outline of: Jan 45, 283
KETSU-GO: 272; 283
Operational Army Group Mobilization Plans
2d: 261; 295
3d: 261; 296; 316
Operational Plan Agst U.S.S.R. in Manchuria and Korea, Outline of: 315
War Matériel, Plan for Reimporting from Manchuria to Japan and Korea: 267
Pogranichnaya (See Suifenho)
Point Taivu: 101-2
Policy, General Outline of Future War Direction: 7 Mar 42, 140; Sep 43, 141
Port Moresby: 72-3; 82-3; 87; 97-8; 104; 106; 119-20
Port Moresby Operation (See Operations)
Potsdam Declaration: 337-8, accepted 341
Prachuap: Japanese troops land at, 62
Premier of Japan: 4; 6-7; 9-10; 33
Preparation, 100th: 32
Prince of Wales: British battleship, sunk, 63
Privy Council: 2; 10-1
Pusan Fortress Unit (See Units)
Quincy: U.S. cruiser, sunk, fn 21, 99
Rabaul: plan to occupy, 53; 60; captured, 63-4; 73; 97-9; 113; 117; 121; 123; 125-6; 128-30; 138; 144; 146; 158; 170; 175
Rabaul Area Operation (See Operations)
Rabi Airfield: 104; 106
Canton-Hankou: 162-5; 271; 310
Dairen-Hsinking: fn 11, 315
Hsinking-Tumen: fn 11, 315
Hunan-Kwangsi: 162-5; 310
Peiping-Hankou: 162-4 Ssupingchien-Chichihaerh: 312
Ralph Talbot: U.S. destroyer, damaged, fn 21, 99
Rangoon: occupied, 69; 90; falls, 253; 271
Rangoon River: 253
Regiments, Ind Mixed, Japanese
Regiments, Inf, Japanese
41st: 100; 108
Regiments, Tank, Japanese 26th: 256
Regulations, Army and Navy General Staff: 1; 2
Rendova Is: 121; enemy lands on, 128
Rennel Is: 106
Repulse: British battleship, sunk, 63
Roi (Marshalls): 147
Russell Is: 109
Russia (See U.S.S.R.)
Russo-Japanese war: 13
Ryujo: Japanese aircraft carrier, sunk, 103
Saigon: troops at, 19; 112; 185; 221
Saipan: 152; Allies capture, 171; 189; 192-4; 198-9; 210
Saishu Is: 270; 332
Saito, Lt. Gen.: committed suicide, 194
Sakaguchi Detachment (See Detachments)
Sakijima Is: 304; 327
Salamaua: 72; 111; 117; 120-1; 123-5; 127; 129-30
Salween River: 69; 122; 165
Samoa: 77, est enemy strength in, 78; 82-4; opn agst cancelled, 87; 96-7
San Cristobal: 106
Santa Isabel Is: 119-20
Sanya: troops at, 19
Sapporo: troops at, 18; 268
Sarumi Is: 170; 176
Sasebo Naval District: 260
Savo Is, Battle of: fn 20, 99
Sealark Channel: fn 22, 99
Second General Army (See Armies)
SEI-GO Operation (See Operations)
Sendai: 228; 247; 268
Seoul: troops at, 18; 310; 332
Seria: oilfields occupied, 66
Seto Naikai (Inland Sea): 116
Shanghai: troops at, 19; 60; 64; 137; 158; re Italians, 167; 181; 204; 208; 238; 304; 308
Shansi Province: 307
Shigemitsu, Mamoru: 11
Shiizaki, Lt. Col., Jiro: 341-2
Shikoku: 228; 242; 247; 265; bombed, 281; 288; 322; 324; 336
Shikoku Military District (See Military Districts)
Shimada, Adm., Shigetaro: 11; appointed Navy C/S, 149
Shimonoseki: raided, 172
Shimonoseki Fortress Unit (See Units)
Shimonoseki-Moji area: mines layed, 318
Shipping Transportation Command (See Commands)
Shizuoka: bombed, 282; 325
SHO-GO Operation (See Operations)
Shortland Is: 120; 123
Siam (See Thailand)
Singapore: 50; surrenders, 63; 75; 90; air bases strengthened, 91; 158; 185-6; 217; 221; 254; 326
Singapore Defense Command (See Commands)
Sino-Japanese war: 13
Sittang River: 69
Slot (Solomons): 99
Soemba Is: 156
Soerabaja: 67; 90
Solomons: 64; 96; 99-100; 102; 104; 106; 108; 110-4; 117; 119-21; 128; Japanese troops withdraw, 129; north strengthened, 130; 146-7; 150; 159
Solomons Operation (See Operations)
Sorong: 152; 177-8; 185
Southeast Area: 105-6; 117; orders and operational plans for, 119; 121; 127; 130-1; 135; 137-40; Allied strength. 142; 145-6; 148; strategy, 149-53; 173; 191; 230
Southeast Area Force (Navy): strength for Solomons Opn, 100; 121
Southeast Area Operation (See Operations)
Southeast Pacific Area: 107-8; 143-4
Southern Area: 13; 17; est of enemy strength in, 34-8; 41; 68; 75-6; 81-2; 88-9O; 92-3; 96; 111; 114; 116; strengthened, 136; 140; 158; 160; 162; 168; 181; unification of command system, 182-5; 187; 201; 223; 228-30; 237; 265-6; 271; 279; 281; 307; 326
Southern Army (See Armies)
Southern Force (Navy): 70-1
Southern Operation (See Operations)
Southern Pacific Area: 145; 149; 183; 243
South Pacific Detachment (See Detachments)
South Pacific Garrison Unit (See Units)
South Pacific Mandated Islands: 144
South Seas Detachments (See Detachments)
South Seas Garrison Units (See Units)
South Seas Islands: 108
Southwest Islands: 46; 159
Southwest Pacific Area: 107; 113; 128; 131-2; troop movements, 135; 139; Allied strength, 142; 144-5; 168; SHO-GO air strength, 207; Navy air strength, Mar 45, 278
Soviet Union (See U.S.S.R.)
Soviet Army, Far Eastern (See Armies)
Soviet Army, in east (See Armies)
Soviet Far East Air Force: 55
Soviet Invasion of Manchuria: preparations agst, 31-2
Soviet-Japanese Neutrality Pact: 236; abrogated, 310; 314
Soviet-Japanese Relations: 30
Soya Fortress Unit (See Units)
Soya Straits: 159; 297-8; 328
2d Destroyer: 66
3d Destroyer: sails into
Muntok, 67; 103
2d Submarine: 71
Stalin: declares Japan aggressor nation, 200
St Andrew Is: 177; 184
Starling Bay: 71
Strategic Collaboration, Army-Navy: 294-5
Sugahara, Lt. Gen.: (Cmdr, 6th Air Army) 303
Sugiyama, Field Marshall, Gen.: (1st Gen Army Cmdr) 11; 339
Suichuan: 164; 271
Sulo Archipelago: 191
Sulu Sea: 224
Sumatra: 34; 50; proposed military administration of, 56; 65; 77; 88; 90-1; fn 26, 112; 113; 134; 144-5; 168; 173; 183; 185; 243; 251; 254
Sunda Is: 271
Sunwu: 314; 336
Supplies, Japanese reserve: 27-9
Supreme Commander: 1-2;, 8-9
Supreme Commander for Allied Powers: 338
Supreme Military Council: 3
Supreme War Council: 8
Supreme War Direction Conference: 7
Supreme War Direction Council: 338
Surface Escort Force: air strength, Mar 45, 278
Suzuka Mt Range: 287; 324-5
Suzuki, Adm. Baron, Kantaro: 11
Suzuki Cabinet: 11
Suzuki, Lt. Gen., Teiichi: 11
Szechuan Province: 77; 81; 114
Tachibana, Lt. Gen., Yoshio: 258
Tahsinganling Mt Range: 336
Takao: troops at, 19
Takao Naval Guard District: 260; 327
Tanaka, Gen., Shizuichi (12th Area Army Cmdr): 342
Tanegashima Is: 242
Tani, Masayuki: 11
Tanimbar Is: 117; 156; 176
Tank production: est enemy increases, 80
Tarawa (Gilberts): 147
Teheran Conference: 148
Tenaru River: 101
TEN-GO Operation (See Operations)
Terauchi, Gen. Count, Juichi: 43
Thai Government: 122
Thailand: 34; air strength in, 37; 47; 49-50; 52; 59-61; Japanese troops enter, 62-3; 88; air bases strengthened in, 91; 122; 135; 160; re Italians, 167; 173-4; 183; 185; 224; 243; 251; 254; 256; 271
Thailand Army (See Armies)
Thailand Garrison Army (See Armies)
Tienching: 60; re Italians, 167
Timor: 50; orders to attack, 64; 90; 135; 156
Tinian: 198; 221
Togo, Shigenori: 11
Toho Detachment (See Detachments)
Tojo Cabinet: 11; 26; 39; 201
Tojo, Gen., Hideki: 11; 39; appointed Army C/S, 149
Tokai, (Nagoya): 242; 269; 318 Tokyo: troops at, 18; fn 1, 149; 196; raided 199; 214; 229; 247; 268; 270; bombed, 281-2; 316-8; 343
Tokyo Bay Fortress Unit (See Units)
Tokyo Defense Army (See Armies)
Torokina (Bougainville): 147
Tou-kou River: 270
Toungoo: occupied, 69; 132; 253
Toyoda, Adm., Soemu: 11; 303
Toyoda, Adm., Teijiro: 11
Training manuals: 17; 22
Training programs: 17
Transportation and Communications, Ministry of: 289-90
Tripartite Alliance: 12; 31
Troop Employment: 292
Truk: 100-1; 103; 147; 152; 173; 189; 325
Tsugaru Fortress: 179
Tsugaru Fortress Unit (See Units)
Tsugaru Straits: 159; 179; 287; 297; 328
Tsushima Strait: 328
Tulagi: 72-3; 96; enemy lands, 98; 100-1; 104; 110
Tumen River: 243
Tungan: troops at, 18; 331
U-GO Operation (See Operations)
Ulithi: 256; 299
Umezu, Gen., Yoshijiro: 11
U.S.S.R.: 12; 14; 23; 31; 39; 41; 54; 58; 61; 74-5; 119; 141; 145-6; 148; 179; 235-6; threat from increases, 238; 244; 264; 284; 298; operational preparations agst, 310-6; 329-30; entry into war, 333-5; 337
United States: 12; 23; oil imported from, 27; oil embargo, 29; 30; 33; strength in south, 34-8; air force in Philippines, 34; 39-41; 45-7; 49; 55; 57-9; strength in, 78; 80; 82; 96; 140-1; 143; 238; 284; 287; 307; 315; 333
U.S. Air Force: raids Japan, 172; 242; 258; drops atomic bomb, 337
U.S. Army (See Armies)
U.S. Fleet: 51; 143
U.S. Marines: 301
U.S. Navy: 147; off Marianas, 171; 258
Amami Oshima Fortress; 180
Chichijima Fortress: 153
Chichijima Garrison: 258
Funafuchi Portress: 180
Hoyo Fortress: 295
Independent Garrison: (in Manila) 113
Iki Fortress: 295
Kume: garrisoned Bandjermasin, 66
Kurile Fortress Infantry: 115
Kurile Islands Garrisons
Kwantung Army Field Railway: 233
Nakgusiku Bay Fortress: 180
North Sea: 115
Pusan Portress: 295
Shimonoseki Fortress: 295
South Pacific Garrisons
South Seas Garrison
1st: destroyed at sea, 130
2d: to Marcus Island, 130-1
3d: to Wake Island, 130
4th: to Bougainville Island, 130-1
Soya Portress: 295
Tokyo Bay Fortress: 295
Tsugaru Fortress: 295
Vincennes, U.S. cruiser: sunk, fn 21, 99
Wake: occupied, 63; 144; 190
Wanchuan: troops at, 19
War: Japan plans, 39
War Minister: 2-7; 10; 340; accepts Emperor's decision, 341
War Preparations: 46
War Sector Armies (Chinese) (See Armies)
Washington: 33; 49; 57-8
Western Army (See Armies)
Western Army Command (See Commands)
West Sunit: 307
Wewak: 111; 120; 127; 175-6
World War I: 12; 22
World War II: 10; preparations for, 12; 14; training for, 23; air training for 24; preparations for, 30-56; operational progress. 61-85; 96
Wuchang-Hankou Defense Army (See Armies)
Wuchang-Hankou Sector: 164; 226-7; 308-9
Yakushima Is: 242
Ya-Lu River: 270
Yamamoto Adm., Isoroku (CinC, Combined Fleet): 70
Yamashita, Gen., Tomoyuki: fn 5, 219; 234
Yangchu: troops at, 19
Yangtze River: 242; 260; 271; 306-10
Yano Bn: to Guadalcanal, 123
Yawata: raided, 172; 196
Yenan Army (Red Chinese) (See Armies)
Yokohama: 196; 246; incendiary bombings, 282
Yokosuka Naval District: 131
Yonai, Adm., Mitsumasa: 11
Yonghung Bay: 316
Yungchia: 199; 226
Yunnan: 136; 162; 165; 187; 198