Additional material is available for the Iwo Jima campaign.

Chapter 13: The Iwo Jima Campaign

With the successful landing in Luzon by forces of the Southwest Pacific Area in January, United States control of the Philippine Archipelago was assured and final severance of the Japanese line of communications to the Southern Resources Area was imminent. As a result of serious losses incurred in the Philippine and previous campaigns together with a breakdown in the pilot replacement program and a critical shortage of fuel, the Japanese Air Forces were no longer capable of effective action when employed in the conventional manner. In desperation they had initiated the "special attack" or "Kamikaze" tactics. United States forces on the other hand were stronger than ever--stronger in numbers, better trained, and moving forward with an overwhelming offensive power. United States domination of the Pacific Ocean Area was complete and the time was at hand to strike in earnest toward the heart of the Japanese Empire.

The Japanese correctly estimated the intention of the United States to attack and seize Iwo Jima under cover of carrier air raids on the Home Islands. In view of the continuing operations in the Philippines it was not considered probable that landing operations in Formosa or the Nansei Shoto would be carried out.

The Joint Chiefs of Staff had directed the Commander in Chief, Pacific Ocean Areas, to occupy one or more position in the Nanpo Shoto with the target date of 19 February 1945, and one or more positions in the Nansei Shoto [Okinawa] with a target date of 1 April 1945. The purpose of these occupations was to acquire additional airfield sites in order to increase the weight of our shore-based air attacks against the Home Islands, to complete the air-sea blockade of Japan, to facilitate preparations for an invasion of the Home Islands, and to maintain unremitting military pressure against Japan.

Accordingly, the Commander in Chief, Pacific Ocean Areas, selected Iwo Jima as the most satisfactory objective in the Nanpo Shoto. This island had three airfields, two operational and one under construction, within escort fighter range of most of the important bombing targets on Honshu, and would provide emergency landing facilities for B-29 operations from the Marianas. The capture and occupation of Iwo Jima had to be effected expeditiously in order to release shipping and naval forces for the impending Nansei Shoto operations.

Japanese operational plans did not provide for any large-scale operations in the defense of Iwo Jima; the Nanpo Shoto was not considered a vital area in the concept of the TEN Operation Plan then in effect. Only local forces were to be employed in the defense of Iwo Jima, together with limited operations of special attack airplanes and piloted torpedoes (Kaitens). Consequently, the Japanese reaction to the invasion fo Iwo Jima was quite limited.

Preliminary bombing of both Iwo Jima and Chichi Jima was conducted by shore-based aircraft from the Marianas. Covering operations for the invasion were begun by the Fast Carrier Force when, on 16-17 February, the first carrier raids on the Japanese Home Islands were made. On these two days and again on the 25th, carrier-based air strikes were made in the Tokyo area. These strikes were notable for the lack of air opposition encountered and for bad weather in the operating areas. Also during these raids a limited number of sorties were directed against strategic targets such as aircraft engine and airplane factories in the Tokyo area.

Preceded by the usual shore bombardment and carrier air strikes, the initial Iwo Jima landings were made on the 19th of February, beginning what developed into the most vicious and hard-fought campaign in the Pacific. The natural terrain features of Iwo Jima together with a very elaborate and complete underground defense system made this island most difficult to occupy. In spite of intense naval gunfire and


air bombardment, the Japanese had to be dug out by ground troops and killed individually. Against such prepared positions direct air support had but limited effectiveness. Ground casualties were high. On 16 March 1945, organized resistance ended.

In support of this operation, from the 12th of February until the end of March, neutralization of Chichi Jima in the Bonins was maintained by B-24's based in the Marianas and by strikes from the escort and fast carrier groups.

Upon completion of the operation, the airfields were rapidly developed. These three airfields were used primarily by fighters escorting the B-29 attacks against Central Honshu. On 8 March, P-51's of the garrison air force commenced operations. Iwo Jima also became a base for reconnaissance and shipping strikes by naval shore-based patrol planes. In United States hands this island became a northern outpost for the protection of vital installations in the Marianas. Before the close of the war, some 2,400 B-29's made emergency landings at Iwo Jima, a substantial number of which might otherwise have been lost.

The cost of the Iwo Jima Campaign to the United States was approximately 21,000 casualties (killed, wounded and missing), 1 escort carrier and one LCI(G) sunk, major damage to 30 ships, and 168 aircraft lost.

As a result of the Iwo Jima Campaign, airfield sites had been acquired about 600 miles closer to the Japanese Home Islands which, together with the increased strength of the Strategic Air Forces in the Marianas, permitted heavier air attacks on the Home Islands. Severe losses had been inflicted on the Japanese Air Force in the Home Islands by the initial carrier raids which, together with Iwo-based fighter sweeps, would thereafter be continued on a much wider scale.

Control of the Pacific areas had been extended still further toward the inner defenses of Japan. United States forces were enroute for the assault on Okinawa, the final bastion of the Japanese inner defenses. Within the Home Islands the Japanese were assembling the remnants of their air and naval forces for a major attempt to defend the Nansei Shoto, the expected objective of the next United States attack. At the same time, frantic preparations were being made for the final defense against the invasion of the Home Islands. Behind the scenes, political maneuverings were being carried out to end the war, thought as yet such efforts could not be made openly.


Interrogations: Comdr. Okumiya, Iwo Jima Operation, Nav No. 27, U.S.S.B.S. No. 104.

Operations in the Pacific Ocean Areas, February 1945, by Commander in Chief {Pacific Fleet] and Pacific Ocean Areas.

Additional information contained in unpublished answers to Naval Analysis Division questionnaires No. 0 and No. 6, which are in U.S.S.B.S. files.


Forces Involved

United States Forces:  
  United States Pacific Fleet Admiral C.W. Nimitz, U.S.N.
  Central Pacific Task Forces (5th Fleet) Admiral R.A. Spruance, U.S.N.
  Joint Expeditionary Forces Vice Admiral R.K. Turner, U.S.N.
  Expeditionary Troops Lt. Gen. H.M. Smith, U.S.M.C.,
3d, 4th, and 5th Marine Divisions
  Amphibious Support Force Rear Admiral W.H.P. Blandy, U.S.N.
  Attack Force Rear Admiral H.W. Hill, U.S.N.
  Gunfire and Covering Force Rear Admiral B.J. Rodgers, U.S.N.
  Fast Carrier Force Vice Admiral M.A. Mitscher, U.S.N.
  Submarine Force Vice Admiral C.A. Lockwood, Jr., U.S.N.
  Strategic Air Forces, POA Lt. Gen. M.F. Harmon, U.S.A.A.F.
  Forward Area Forces Vice Admiral J.H. Hoover, U.S.N.
  The Joint Expeditionary Force consisted of 495 ships, with 352 supporting aircraft.
  The Gunfire and Covering Force consisted of 7 old battleships, 4 heavy cruisers, and 15 destroyers.
  The Support Carrier Group contained 11 escort carriers.
  The Expeditionary Troops consisted of 11,308 troops, of this number 75,144 were assault troops and 36,164 garrison troops.
  The Fast Carrier Force consisted of 118 ships: 17 aircraft carriers, 8 battleships, 1 large cruiser, 3 heavy cruisers, 12 light cruisers, and 77 destroyers. Embarked aircraft totalled 1,170.
Japanese Forces:  
  Combined Fleet Admiral Toyoda, I.J.N.
  First Diversionary Attack Force (2d Fleet) Vice Admiral Ito, I.J.N.
  6th Fleet (submarines) Vice Admiral Miwa, I.J.N.
  3d Air Fleet Vice Admiral Teraoka, I.J.N.
Nanpo Islands Air Group:  
  The First Diversion Attack Force, consisting of units of the 2d Fleet, comprised 3 battleships, 2 battleship carriers, 2 heavy cruisers, 2 light cruisers, and 25 destroyers, In addition to units of the 2d Fleet, there were two aircraft carriers, two small aircraft carriers, and one escort carrier in the 3d Fleet, however, these carriers were not operational as no air groups were available.
  The 6th Fleet had approximately 15 operational submarines.
  The 3d Air Fleet contained approximately 400 operational aircraft.
  The Nanpo Islands Air Group consisted of six fighters and four bombers at Iwo Jima, and three seaplanes used for escort duty at Chichi Jima.
  No Japanese surface forces were committed to this operation. A small number of submarines, including midgets, did participate. The exact number is not known.
  Of the 3d Air Fleet, only approximately 40 planes (24 suicide) participated in the defense of Iwo Jima.

Appendix 96


Detailed Losses

United States Losses (from United States Sources)
Agent Sunk Damaged
Suicide planes 1 3
Bombs 0 1
Shore batteries 1 15
Operational  0  11
     Totals 2 30
Aircraft:   Personnel (does not include naval losses):
  To enemy antiaircraft 77     Killed 4,590
  To enemy aircraft 40     Missing 301
  Operational  51     Wounded  15,954
       Total 168          Total 20,845

Japanese Losses
  Sunk: Damaged:
  2 submarines.   5 lookout ships.
  4 lookout ships.  
Aircraft (period 1 February--1 March 1945)
Service Combat Operational Total
Army 150 150 300
Navy 1187  245  432
     Totals  1337 395 732
1 24 suicide.
    Counted and buried 13,234
  Estimated sealed in caves or buried by enemy   8,070
       Total 21,304
  Prisoners of War 212

Appendix 97


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