Page 387 

ENDORSEMENTS BY JAG, COMINCH AND SECNAV TO ADMIRAL HEWITT'S REPORT 
 
[TOP-SECRET] 
 
                         UNITED STATES FLEET 
                HEADQUARTERS OF THE COMMANDER IN CHIEF 
                           NAVY DEPARTMENT 
                  Washington 25, D. C., 13 Aug. 1945. 
 
FF1/A17 
Serial: 002008 
Top Secret 
 
Third endorsement to Adm. Hewitt's Report to SecNav dated 12 July 1945. 
From: Commander in Chief, United States Fleet and Chief of Naval  
Operations  
To: The Secretary of the Navy. 
Subject: Report of Further Pearl Harbor Investigation by Admiral H. K.  
Hewitt, U. S. Navy. 
 
1. I concur in general in the remarks and recommendations of the Judge  
Advocate General as expressed in the second endorsement. In answer to  
the specific questions asked in the first endorsement, the following  
opinions are submitted:  
 
(a) I am of the opinion that the evidence is not sufficient to warrant  
trial by court martial of any person in the Naval Service, in that the  
evidence will not sustain the charges required by the Articles for the  
Government of the Navy. 
 
(b) With regard to the sufficiency of the evidence to warrant other  
proceedings, I am still of the opinion, which I have previously  
expressed, that Admiral Stark and Admiral Kimmel, though not culpable to  
a degree warranting formal disciplinary action, were nevertheless  
inadequate in emergency, due to the lack of the superior judgment  
necessary for exercising command commensurate with their duties.  
 
(c) Appropriate action appears to me to be the relegation of both of  
these officers to positions in which lack of superior strategic judgment  
may not result in future errors. The action has been taken in the case  
of both Admiral Stark and Admiral Kimmel. No further action is  
recommended.  
 
(d) For the reasons stated by the Judge Advocate General, I consider it  
impracticable to bring Admiral Stark and Admiral Kimmel, or either one  
of them, trial prior to the termination of hostilities with Japan, nor  
are court martial other proceedings (prior to the termination of  
hostilities with Japan) advisable because such proceedings would almost  
certainly involve disclosure of information which would be detrimental  
to current military operations and to national security measures.  
 
2. I concur in the opinion of the Judge Advocate General that the Navy  
Department is morally obligated to order Admiral Kimmel to trial before  
a General Court Martial, should Admiral Kimmel so insist. However, this  
action could not he taken until after the completion of hostilities with  
Japan. 
 
3. I concur in the suggestion of the Judge Advocate that this record be  
made available to Admiral Kimmel and his counsel; that Admiral Kimmel be  
informed that he is free to make public anything contained in this  
record and prior records as soon as that may be done without prejudice  
to security; that if Admiral Kimmel insists, a General Court Martial  
will be convened to try him for alleged offenses he may have committed  
on or before December 7, 1941. 
 
4. As to Admiral Hewitt's deductions from war experience-paragraph 28.  
page 180-I am unable to concur fully with (a) thereof but do concur  
fully with (b) thereof. Nor am I able to concur fully in his paragraph  
29 (page l80)-which parallels his paragraph 28 (a)-for the reason that  
he himself sets forth substance at various places in his "findings" and  
"conclusions", namely that while the system of command was that of  
mutual cooperation it was, in reality, complete and inadequate  
implementation of that system which was at fault. 
 
Page 388 
 
There is the further fact that, given the information which was  
available in Washington, it is reasonable to assume that the system of  
mutual cooperation would have been fully alerted and made to function  
effectively. 
 
                                                             E. J. KING. 
 
Otis  
Originated by F-00 (Adm. Edwards) 8/10/45.  
Rewritten by F-0 (Adm. King) 8/13/45.  
 
10 AUGUST 1945. 

Top Secret 
Second Endorsement. 
From: The Judge Advocate General. 
To: Commander-in-Chief, United States Fleet and Chief of Naval  
Operations. 
Subject: Report of further Pearl Harbor investigation by Admiral H. K.  
Hewitt, U. S. Navy.  
 
1. Subject report clarifies obscure points and supplies omissions in the  
earlier investigations. It is considered that this and former  
investigations, taken together, present as clear a picture of the  
pertinent facts as will ever be adduced. With this report, therefore. I  
believe the investigation of the Pearl Harbor attack should be  
considered completed.  
 
2. Admiral Hewitt's report brings out and confirms a distinction which  
impressed me at the time of studying the earlier investigations, a  
distinction which does much to clarify thinking on the question of  
placing responsibility for the Pearl Harbor disaster. It appears that  
there was no lack of appreciation on the part of any of the responsible  
officers that war was coming, and coming quickly, during the critical  
period immediately preceding 7 December 1941. The point on which those  
officers failed to exercise the discernment and judgment to be expected  
from officers occupying their positions, was their failure to  
appreciate, from the information available to them, that Pearl Harbor  
was a likely target for aerial attack and their failure to take the  
necessary steps to prevent or minimize such a surprise attack. Each of  
these officers, in estimating the critical situation, demonstrated a  
poor quality of strategical planning, in that he largely ruled out all  
possible courses of action by which the Japanese might begin the war  
except through an attack in the Western Pacific.  
 
3. I do not believe that the lack of more complete understanding and  
cooperation between Admiral Kimmel and Lieutenant General Short had any  
great effect on the ultimate result; for it is abundantly shown that  
they each entertained the same fallacious views, and closer  
understanding would most likely merely have strengthened those views.  
Likewise, I submit that the importance of information from Japanese  
sources has been overemphasized, for had more basically sound principles  
been observed, the Pearl Harbor disaster would not have occurred. The  
security of Pearl Harbor was the very core of our Pacific strategy, a  
fact which did not receive sufficient consideration in the strategic  
concept of responsible officers. 
 
4. In answer to the specific questions asked in the first endorsement.  
The following opinions are submitted:  
 
(a) As is more fully developed in the answer to question (b), it is not  
believed that there is sufficient evidence to warrant conviction of any  
of the officers concerned of any offense known to naval law.  
 
(b) Under the facts of this ease, there are only two offenses which are  
worthy of consideration (1) Neglect of Duty and (2) Culpable  
Inefficiency in the Performance of Duty. Under either charge it would he  
necessary to define the duty of the officer concerned, and to show that  
it was his duty to follow a course of action other than the one he did.  
In my opinion this would be impossible, as the acts of omission of these  
officers do not rise above the status of errors of judgment. No clearly  
defined duty can be established which was neglected or improperly  
performed. As stated by Fleet Admiral King, in his endorsement on the  
findings of the Court of Inquiry, the evidence in the case boils down to  
the fact that the acts of the officers in question "indicate lack of  
superior judgment necessary for exercising command commensurate with  
their rank and their assigned duties, rather than culpable  
inefficiency". "Lack of Superior Judgment" is not an offense triable by  
general court-martial.  
 
(c) The charges and specifications for any court-martial proceedings  
must be filed not later than a date "six months after the termination of  
hostilities in the present war with Japan as proclaimed by the President  
or as specified in a con- 
 
Page 389 
 
current resolution of the two Houses of Congress, whichever is the  
earlier". Public Law 77-79th Congress, approved June 7, 1945. There are  
serious doubts as to the constitutionality of this and the earlier  
extensions of the Statute of Limitations enacted by the Congress since 7  
December 1941 and applicable to trials arising out of the Pearl Harbor  
disaster as a violation of the Constitutional prohibition against ex  
post facto laws. Admiral Kimmel has executed a waiver of the Statute of  
Limitations for a period of six months past the end of the present war,  
and therefore the question of the validity of the Congressional  
extensions is not controlling in his case. However, as it has become  
apparent since the time that Admiral Kimmel was requested to execute  
this waiver that other officers are also blameworthy, it is my opinion  
that the Navy Department would be acting in an inequitable manner in  
instituting any proceedings against Admiral Kimmel on his waiver, unless  
Admiral Kimmel himself so requests. 
 
(d) The requirements of 39th Article for the Government of the Navy and  
Section 346 of Naval Courts and Boards pertaining to the rank of members  
of a general court-martial will make it most difficult to constitute a  
court for the trial of the officers here concerned during war time or  
during a period of six months after the cessation of hostilities. Many  
of the officers of appropriate rank, both on the active and the retired  
lists, would be disqualified because of interest in the subject matter,  
the probability of being called as a witness, or by virtue of having  
been connected with one of the investigations into the matter. If more  
than one of the officers in question are brought to trial, an entirely  
new court would be necessary in each case, as members who had tried a  
former case arising out of the Pearl Harbor attack would be subject to  
challenge. The Summoning of the necessary witnesses would result in  
temporarily removing from their duty stations many of the key officers  
in the naval organization. For the foregoing reasons, I am of the  
opinion that any such court martial proceedings prior to the end of  
hostilities with Japan is highly impractical and would be detrimental to  
the war effort, and further, that any such proceedings during the six  
months immediately following the end of hostilities would seriously  
impair the efficiency of the naval service.  
 
5. Notwithstanding the difficulties pointed out above, I am of the  
opinion that the Navy Department is morally obligated to order Admiral  
Kimmel tried by general court-martial should Admiral Kimmel so insist.  
In August 1943, Secretary Knox sent Admiral Kimmel a memorandum from  
which the following is quoted, "I feel that it would be to the best  
interests of all concerned if you should now agree not to plead the  
statute of limitations in bar of trial upon my assurance that the trial  
will be had at the earliest practicable date." And in Admiral Kimmel's  
waiver he agreed, "I will not plead, nor permit any attorney or other  
person on my behalf to plead, the statute of limitations in bar of my  
trial by General Court-Martial in open court for any alleged offenses  
with which I may be charged relating to the period on or before December  
(sic) 7th, 1941, should my trial be held during the present war or  
within six (6) months thereafter."  
 
6. I suggest that this record be made available to Admiral Kimmel and  
his counsel; that Admiral Kimmel be informed that he is free to make  
public anything contained in this record and prior records as soon as  
that may be done without prejudice to the public interests; that if he  
insists a general court-martial will be convened to try him for alleged  
offenses he may have committed on or before December 7, 1941; and that  
his decision be abided.  
 
T. L. GATCH.  
 
25 JULY 1945. 

First Endorsement. 
To: The Judge Advocate General.  
Commander-in-Chief, United States Fleet and Chief of Naval Operations. 
Subject: Record of proceedings and Report of further Pearl Harbor  
investigation by Admiral H. Kent Hewitt, USN.  
 
1. Forwarded for comment and recommendation.  
 
2. The endorsement by the Judge Advocate General will include his  
opinion (a) as to the sufficiency of the evidence to warrant court- 
martial or other proeeedings, (b) as to the offense or offenses which  
might be made the subject of court-martial or other proceedings,  
assuming the sufficiency of the evidence concerning such offense or  
offenses, (c) as to the date prior to which any such court-martial or  
other proceeding must be instituted, and (d) as to the practicability of  
any such court-martial or other proceeding prior to the termination of  
hostilities with Japan, particularly in view of the regulations  
concerning  
 
Page 390 
 
the composition of a court and in view of the necessity of obtaining  
testimony from witnesses engaged in operations against the enemy. 
  
3. The endorsement by the Commander-in-Chief, United States Fleet and  
Chief of Naval Operations will include his opinion (a) as to the  
sufficiency of the evidence to warrant court-martial or other  
proceedings, (b) as to the practicability of any such court-martial or  
other proceeding prior to the termination of hostilities with Japan,  
particularly in view of the regulations concerning the composition of a  
court and in view of the necessity of obtaining testimony from witnesses  
engaged in operations against the enemy, and (c) as to the advisability  
of any such court-martial or other proceeding prior to the termination  
of hostilities with Japan, particularly in view of the possibility of  
disclosure of information relating to current and prospective military  
operations and to national security. 
 
                                                               FORRESTAL 
 
                                                           12 JULY 1945. 
From: H. Kent Hewitt, Admiral, U. S. Navy.  
To: The Secretary of the Navy. 
Subject: Report of further investigation into the facts surrounding the  
Japanese attack on Pearl Harbor, 7 December 1941.  
 
Reference: 
(a) Report of Commission appointed by the President to investigate and  
report the facts relating to the Japanese attack on Pearl Harbor, 7  
December 1941.  
(b) Record of examination of witnesses having knowledge of the facts in  
connection with the Japanese attack on Pearl Harbor, conducted by  
Admiral Thomas C. Hart, USN (Ret.).  
(c) Public Law 339, 78th Congress.  
(d) Precept appointing Naval Pearl Harbor Court of Inquiry, 13 July  
1944.  
(e) Record of proceedings and: report of Naval Pearl Harbor Court of  
Inquiry.  
(f) First Endorsement, dated 2 November 1944, by the Judge Advocate  
General, and Second Endorsement, dated 6 November 1944, by Commander in  
Chief, U. S. Fleet and Chief of Naval Operations, to record of  
proceedings of Naval Pearl Harbor Court of Inquiry.  
(g) Report of Army Pearl Harbor Board, dated 20 October 1944.  
(h) Letter 3 December 1944 from Commander in Chief, U. S. Fleet and  
Chief of Naval Operations, to the Secretary of the Navy, on report of  
Army Pearl Harbor Board.  
(i) Precept 2 May 1945 appointing H. Kent Hewitt, Admiral, U. S. Navy,  
to conduct further Pearl Harbor investigation.  
(j) Memorandum 18 May 1945, concerning the scope of the further  
investigation and approval thereof by the Secretary of the Navy.  
(k) Precept 6 July 1945 amending reference (I). 
 
Enclosure: 
 
(A) Report of further investigation into the facts surrounding the  
Japanese attack on Pearl Harbor, 7 December 1941.  
(B) Record of proceedings of this investigation, and exhibits therein. 
  
1. The precept of the Secretary of the Navy, dated 2 May 1945, reference  
(i) as amended by reference (k), directed that Admiral H. Kent Hewitt,  
USN, make a study of the previous investigations, that such further  
investigation as might appear to be necessary be then conducted, and,  
that upon completion of the investigation a report be submitted to the  
Secretary of the Navy setting forth the findings and conclusions  
reached. 
 
Review of the previous investigations disclosed that various matters of  
importance, principally concerning intelligence, had not been  
investigated thoroughly. The subjects proposed for further investigation  
were approved by the Secretary of the Navy on 21 May 1945. 
 
3. Counsel in this investigation was John F. Sonnett, Special Assistant  
to the Secretary of the Navy. Also assisting were Lieutenant Commander  
Benjamin H. Griswold, III, USNR, and Lieutenant John Ford Baecher, USNR.  
The reporters were Ship's Clerk Ben Harold, USNR, and Chief Yeoman  
Raymond E. Reese, USNR. These men took a special oath to maintain the  
security of the information developed during the investigation. 
 
Page 391 
 
4. During this proceeding, which commenced 14 May 1945, the testimony of  
38 witnesses, some of whom had testified previously, was taken on 26  
days, at Washington, D. C., at San Francisco, and at Pearl Harbor. 81  
exhibits were received.  
 
5. Delivered herewith are the report of this further investigation  
(Enclosure A), and the record of proceedings and exhibits therein  
(Enclosure B). In preparing this report, an effort has been made to  
present, in one document, the essential facts within the scope of this  
inquiry which have been developed by this and preceding investigations.  
 
                                                         H. KENT HEWITT. 
 
Page 392 
 
[Blank] 
 
Page 393 

REPORT BY ADMIRAL H. K. HEWITT ON FURTHER PEARL HARBOR INVESTIGATION 
 
TABLE OF CONTENTS 
 
Introduction. Prior Investigations and Scope of this Investigation   
                                                                    Page 
[Page references are to the original document, not the PHA Vol. 39.
PHA page number are included, but the numbers below are the ones in 
[brackets] in the text.]
 
  A. The Roberts Commission ........................................   1 
  B. Admiral Hart's Investigation ..................................   4 
  C. Naval Court of Inquiry ........................................   4 
  D. Army Pearl Harbor Report ......................................  11 
  E. Findings of the Secretary of the Navy and further  
     investigation .................................................  14 
  F. Witnesses in this investigation ...............................  15 
  G. Exhibits received in this investigation .......................  18 
 
Section I. The War and Defense Plans. 
  A. U. S. Pacific Fleet Operating Plan Rainbow Five ...............  23 
  B. Joint Coastal Frontier Defense Plan, Hawaiian Theater, Orange 
     14ND-JCD-42 ...................................................  31 
  C. Annex VII, Section VI to the Joint Coastal Frontier Defense 
     Plan ..........................................................  34 
  D. Joint estimate covering Army and Navy air action in the event of 
     sudden hostile action against Oahu ............................  35 
  E. Naval Base Defense Force Operation Plan No. 1-41 and Naval 
     Base Defense Air Force Plan ...................................  37 
  F. Pacific Fleet Letter on security of the fleet at base and in  
     operating areas ...............................................  39 
  G. Execution of Plans prior to 7 December 1941 ...................  41 
  H. Admiral Kimmel's views as to the possibility of a surprise air 
     attack ........................................................  42 
  I. Adequacy of forces to carry out tasks assigned ................  44 
  J. Command Organization ..........................................  45 
  Findings .........................................................  49 
 
Section II. Japanese Espionage at Hawaii. 
  Espionage Reports ................................................  53 
  Findings .........................................................  59 
 
Section III. Naval Intelligence and Events Preliminary to the Attack. 
  A. The organization of Naval Intelligence in general; sources of  
     information, and relations with the Pacific Fleet .............  60 
  B. The approach of war; intercepted communications available at 
     Washington, and messages sent by CNO to Admiral Kimmel.  
     1. The resignation of the Japanese Cabinet and October 16th 
        dispatch ...................................................  62 
     2. Japanese messages concerning German attitude; Nomura's  
        desire to resign ...........................................  63 
     3. Action taken by Admiral Kimmel .............................  64 
     4. The first Japanese deadline message; Japanese interest in 
        American ships .............................................  65 
     5. Arrival of Kurusu; Stark and Marshall recommendations 
        as to ultimatum ............................................  65 
     6. Further and final Japanese "deadline messages" .............  66
     7. The November 24th dispatch to CincPac and others ...........  67 
     8. Dispatches concerning reinforcement of Wake and Midway .....  68 
     9. Intercepted Japanese communications of November 26th 
        and 27th ...................................................  69 
    10. The State Department note of November 26th and Japanese  
        reaction thereto; the war warning of November 27th .........  70 
 
Page 394 
 
Section III. Naval Intelligence-Continued                           Page 
  B. The approach of war-Continued 
    11. The dispatch of November 28th ..............................  73 
    12. Intercepted diplomatic communications, November 29 to 
        6 December 1941 ............................................  74 
    13. Intercepted Japanese espionage messages between 29 
        November and 6 December 1941 ...............................  82 
    14. Intercepted message advising of fourteen-part reply by Japan- 
        ese and first thirteen parts of reply-6 December 1941 ......  82 
    15. Communications intercepted on 7 December 1941 ..............  83 
    16. Delivery of part 14 and the 1 p. m. message and action  
        taken ......................................................  85 
    17. Messages sent to Admiral Kimmel between 29 November and 7  
        December 1941 ..............................................  87 
    18. Admiral Kimmel's failure to transmit information to 
        subordinate commanders .....................................  87 
  C. The interception of Japanese telephone and cable messages .....  88 
  D. The "winds" code and the alleged "winds" message 

     1. Prior investigations .......................................  95 
     2. The basis of the previous findings that there was a "winds" 
        executive [sic] message prior to the attack ................  97 
     3. Evidence obtained in this investigation concerning "winds" 
        message .................................................... 100 
  E. Information concerning the organization of the Japanese Navy. 
     1. ONI report of 25 July 1941 ................................. 107 
     2. Pacific Fleet Intelligence Bulletin No. 45-41 .............. 107 
  F. Information concerning the location and movements of Japanese 
     naval forces. 
     1. Information available at the time of the war warning ....... 110 
     2. Admiral Kimmel's source of information after the war  
        warning .................................................... 111 
     3. Information received by Admiral Kimmel after the war  
        warning .................................................... 112 
  Findings ......................................................... 125

Section IV. Reconnaissance. 
  A. The Responsibility for Long Distance Reconnaissance ........... 134 
  B. Reconnaissance Conducted from Oahu ............................ 135 
  C. Proposed Army Reconnaissance to Jaluit ........................ 136 
  D. The Direction to Execute an Appropriate Defensive Deployment .. 137 
  E. The Reconnaissance that could have been flown ................. 137 
  F. The Sectors which would have been covered ..................... 139 
  Findings ......................................................... 140 
 
Section V. The Attack on Pearl Harbor 
  A. Japanese submarines on 7 December 1941 ........................ 143 
  B. Suspicious submarine contacts prior to 7 December 1941 ........ 148 
  C. Detection of Aircraft by the Army Radar System ................ 149 
  D. The Air Attack ................................................ 149 
  E. Location of Pacific Fleet Units ............................... 151 
  F. Condition of Readiness ........................................ 153 
  G. Reaction to the Attack ........................................ 153 
  H. Composition and Movements of the Attacking Force .............. 155 
  I. The Casualties and Damage ..................................... 156 
  Findings ......................................................... 157 
 
Section VI. Findings and Conclusions. 
  A. Restatement of Findings ....................................... 159 
  B. Conclusions ................................................... 175 
 
Page 395 
 
REPORT OF HEWITT INQUIRY          390 
 
[ /]               INTRODUCTION 
PRIOR INVESTIGATIONS AND SCOPE OF THIS INVESTIGATION 

A. The Roberts Commission.  

Pursuant to Executive Order dated 18 December 1941, a Commission, headed  
by Mr. Justice Owen J. Roberts, conducted an investigation into the  
facts surrounding the Japanese attack on Pearl Harbor. The Commission  
reported its findings on 23 January 1942 and concluded:  
 
1. Effective utilization of the military power of the Nation is  
essential to success in war and requires: First, the coordination of the  
foreign and military policies of the Nation; and, second, the  
coordination of the operations of the Army and Navy.  
 
2. The Secretary of State fulfilled his obligations by keeping the War  
and Navy Departments in close touch with the international situation and  
fully advising them respecting the course and probable termination of  
negotiations with Japan.  
 
3. The Secretary of War and the Secretary of the Navy fulfilled their  
obligations by conferring frequently with the Secretary of State and  
with each other and by keeping the Chief of Staff and the Chief of Naval  
Operations informed of the course of the negotiations with Japan and the  
significant implications thereof.  
 
4 The Chief of Staff and the Chief of Naval Operations fulfilled their  
obligations by consulting and cooperating with each other, and with  
their superiors, respecting the joint defense of the Hawaiian coastal  
frontier; and each knew of, and concurred in, the warnings and orders  
sent by the other to the responsible commanders with respect to such  
defense.  
 
5. The Chief of Staff of the Army fulfilled his command responsibilities  
by issuing a direct order in connection with his warning of probable  
hostilities. In the following words "Prior to hostile Japanese action  
you are directed to undertake such reconnaissance and other measures as  
you deem necessary."  
 
6. The Chief of Naval Operations fulfilled his command responsibility by  
issuing a warning and by giving a direct order to the commander in  
chief, Pacific Fleet, in the following words:  
 
"This despatch is to be considered a war warning." 
 
and  
 
"Execute an appropriate defensive deployment preparatory to carrying out  
the tasks assigned."  
 
[2] 7. The responsible commanders in the Hawaiian area, in fulfillment  
of their obligation to do so, prepared plans which, if adapted to and  
used for the existing emergency, would have been adequate.  
 
8. In the circumstances the responsibility of these commanders was to  
confer upon the question of putting into effect and adapting their joint  
defense plans.  
 
9. These commanders failed to confer with respect to the warnings and  
orders issued on and after November 27, and to adapt and use existing  
plans to meet the emergency.  
 
10. The order for alert No. 1 of the Army command in Hawaii was not  
adequate to meet the emergency envisaged in the warning messages.  
 
11. The state of readiness of the Naval forces on the morning of  
December 7 was not such as was required to meet the emergency envisaged  
in the warning messages.  
 
12. Had orders issued by the Chief of Staff and the Chief of Naval  
Operations November 27, 1941, been complied with, the aircraft warning  
system of the Army should have been operating; the distant  
reconnaissance of the Navy, and the inshore air patrol of the Army,  
should have been maintained; the antiaircraft batteries of the Army and  
similar shore batteries of the Navy, as well as additional antiaircraft  
artillery located on vessels of the fleet in Pearl Harbor should have  
been manned and supplied with ammunition, and a high state of readiness  
of aircraft should have been in effect. None of these conditions was in  
fact inaugurated or maintained for the reason that the responsible  
commanders failed to consult and cooperate as to necessary action based  
upon the warnings and to adopt measures enjoined by the orders given  
them by the chiefs of the Army and Navy commands in Washington.  
 
Page 396 
 
13. There were deficiencies in personnel, weapons, equipment, and  
facilities to maintain all the defenses on a war footing for extended  
periods of time, but these deficiencies should not have affected the  
decision of the responsible commanders as to the state of readiness to  
be prescribed.  
 
14. The warning message of December 7, intended to reach both commanders  
in the field at about 7 a. m. Hawaiian time, December 7, 1941 was but an  
added precaution, in view of the warnings and orders previously issued.  
If the message had reached its destination at the time intended, it  
would still have been too late to be of substantial use, in view of the  
fact that the commanders had failed to take measures and make  
dispositions prior to the time of its anticipated receipt which would  
have been effective to warn of the attack or to meet it.  
 
[3]  16. The failure of the officers in the War Department to observe  
that General Short, neither in his reply of November 27 to the Chief of  
Staff's message of that date, nor otherwise, had reported the measures  
taken by him and the transmission of two messages concerned chiefly with  
sabotage which warned him not to resort to illegal methods against  
sabotage or espionage, and not to take measures which would alarm the  
civil population, and the failure to reply to his message of November 29  
outlining in full all the actions he had taken against sabotage only and  
referring to nothing else, tended to lead General Short to believe that  
what he had done met the requirements of the warnings and orders  
received by him. 
 
16. The failure of the commanding general, Hawaiian Department, and the  
commander in chief, Pacific Fleet, to confer and cooperate with respect  
to the meaning of the warnings received and the measures necessary to  
comply with the orders given them under date of November 27,1941,  
resulted largely from a sense of security due to the opinion prevalent  
in diplomatic, military and naval circles, and in the public press, that  
any immediate attack by Japan would be in the Far East. The existence of  
such a view, however prevalent, did not relieve the commanders of the  
responsibility for the security of the Pacific Fleet and our most  
important outpost.  
 
17. In the light of the warnings and directions to take appropriate  
action, transmitted to both commanders between November 27 and December  
7, and the obligation under the system of coordination then in effect  
for joint cooperative action on their part, it was a dereliction of duty  
on the part of each of them not to consult and confer with the other  
respecting the meaning and intent of the warnings, and the appropriate  
measures of defense required by the imminence of hostilities. The  
attitude of each, that he was not required to inform himself of, and his  
lack of interest in, the measures undertaken by the other to carry out  
the responsibility assigned to such other under the provisions of the  
plans then in effect, demonstrated on the part of each a lack of  
appreciation of the responsibilities vested in them and inherent in  
their positions as commander in chief, Pacific Fleet, and commanding  
general, Hawaiian Department.  
 
19. Causes contributory to the success of the Japanese attack were:  
 
Disregard of international law and custom relating to declaration of war  
by the Japanese and the adherence by the United States to such laws and  
customs.  
 
Restrictions which prevented effective counterespionage.  
 
Emphasis in the warning messages on the probability of aggressive action  
in the Far East, and on anti-sabotage measures.  
 
[4]  Failure of the War Department to reply to the message relating to  
the anti-sabotage measures instituted by the Commanding General,  
Hawaiian Department.  
 
Non-receipt by the interested parties, prior to the attack, of the  
warning message of December 7,1941  
 
20. When the attack developed on the morning of December 7,1941, the  
officers and enlisted men of both services were present in sufficient  
number and were in fit condition to perform any duty. Except for a  
negligible number, the use of intoxicating liquor on the preceding  
evening did not affect their efficiency.  
 
21. Subordinate commanders executed their superiors' orders without  
question. They were not responsible for the state of readiness  
prescribed.  
 
B. Admiral Hart's Investigation.  

Pursuant to precept of of the Secretary of the Navy dated 12 February  
1944, Admiral Thomas C. Hart, USN (Retired), conducted an examination of  
witnesses having knowledge of facts in connection with  
 
Page 397 
 
the Japanese attack. Admiral Hart completed his examination on 15 June  
1944.  
 
C. Naval Court of Inquiry.  
 
Public Law No. 339, 78th Congress, approved 13 June 1944, directed the  
Secretary of War and the Secretary of the Navy, severally, to proceed  
forthwith to investigate the facts surrounding the Pearl Harbor  
catastrophe, and to commence such proceedings against such persons as  
the facts might justify.  
 
A Court of Inquiry, consisting of Admiral Orin G. Murfin, USN (Retired),  
Admiral Edward C. Kalbfus, USN (Retired), and Vice Admiral Adolphus  
Andrews, USN (Retired), with Commander Harold Biesemeier, USN, as Judge  
Advocate, was appointed by the Secretary of the Navy on 13 July 1944.  
The Court was directed to convene on 17 July 1944, or as soon thereafter  
as practicable, for the purpose of inquiring into all circumstances  
connected with the attack made by Japanese forces on Pearl Harbor,  
Territory of Hawaii, on 7 December 1941; to inquire thoroughly into the  
matter, and to include in its findings a full statement of the facts it  
might deem to be established. The Court was further directed to state  
its opinion as to whether any offenses were committed or serious blame  
incurred on the part of any person or persons in the Naval service, and,  
in case its opinion was that offenses had been committed or serious  
blame incurred, to recommend specifically what further proceedings  
should be had. The Court of Inquiry commenced its proceedings on 31 July  
1944, and submitted the record of its proceedings on 20 October 1944.  
 
[5]   The Court of Inquiry concluded:  
 
Based on finding II, the Court is of the opinion that the presence of a  
large number of combatant vessels of the Pacific Fleet in Pearl Harbor  
on 7 December 1941, was necessary, and that the information available to  
the Commander-in-Chief, Pacific Fleet, did not require any departure  
from his operating and maintenance schedules.  
 
Based on Finding III, the Court is of the opinion that the  
Constitutional requirement that, prior to a declaration of war by the  
Congress, no blow may be struck until after a hostile attack has been  
delivered prevented the Commander-in-Chief, Pacific Fleet, from taking  
offensive action as a means of defense in the event of Japanese vessels  
or planes appearing in the Hawaiian area, and that it imposed upon him  
the responsibility of avoiding taking any action which might be  
construed as an overt act.  
 
Based on Finding V, the Court is of the opinion that the relations  
between Admiral Husband E. Kimmel, U. S. N., and Lieut. General Walter  
C. Short, U. S. Army, were friendly, cordial and cooperative, that there  
was no lack of interest, no lack of appreciation of responsibility, and  
no failure to cooperate m the part of either, and that each was  
cognizant of the measures being undertaken by the other for the defense  
of the Pearl Harbor Naval Base to the degree required by the common  
interest.  
 
Based on Finding VI, the Court is of the opinion that the deficiencies  
in personnel and material which existed during 1941, had a direct  
adverse bearing upon the effectiveness of the defense of Pearl Harbor on  
and prior to 7 December.  
 
Based on Finding VII, the Court is of the opinion that the superiority  
of the Japanese Fleet over the U. S. Pacific Fleet during the year 1941,  
and the ability of Japan to obtain military and naval information gave  
her an initial advantage not attainable by the United States up to 7  
December 1941.  
 
Based on Finding VIII, the Court is of the opinion that the defense of  
the Pearl Harbor Naval Base was the direct responsibility of the Army,  
that the Navy was to assist only with the means provided the 14th Naval  
District, and hat the defense of the base was a joint operation only to  
this extent. The Court is further of the opinion that the defense should  
have been such as to  
 
Page 398 
 
function effectively independently of the Fleet, in view of the  
fundamental requirement that the strategic freedom of action of the  
Fleet must be assured demands that the defense of a permanent naval base  
be so effectively provided for and conducted as to remove any anxiety of  
the Fleet in regard to the security of the base, or for that of the  
vessels within its limits  
 
[6]  Based on Findings IV, VIII and IX, the Court is of the opinion that  
the duties of Rear Admiral Claude C. Bloch, U. S. N., in connection with  
the defense of Pearl Harbor, were performed satisfactorily.  
 
Based on Finding XI, the Court is of the opinion that the detailed Naval  
Participation Air Defense plans drawn up and jointly agreed upon were  
complete and sound in concept, but that they contained a basic defect in  
that naval participation depended entirely upon the availability of  
aircraft belonging to and being employed by the Fleet, and that on the  
morning of 7 December these plans were ineffective because they  
necessarily were drawn on the premise that there would be advance  
knowledge that an attack was to be expected within narrow limits of  
time, which was not the case on that morning.  
 
The Court is further of the opinion that it was not possible for the  
Commander-in-Chief, Pacific Fleet, to make his Fleet planes permanently  
available to the Naval Base Defense Officer in view of the need for  
their employment with the Fleet.  
 
Based on Finding X, the Court is of the opinion that Admiral Kimmel's  
action, taken immediately after assuming command, in placing in effect  
comprehensive instructions for the security of the Pacific Fleet at sea  
and in the operating areas, is indicative of his appreciation of his  
responsibility for the security of the Fleet and that the steps taken  
were adequate and effective.  
 
Based on Finding XI, the Court is of the opinion that, by virtue of the  
information that Admiral Kimmel had at hand which indicated neither the  
possibility nor the imminence of an air attack on Pearl Harbor, and  
bearing in mind that he had no knowledge of the State Department's note  
of 26 November, the Navy's condition of readiness on the morning of 7  
December, 1941, which resulted in the hostile planes being brought under  
heavy fire of the ships' anti-aircraft batteries as they came within  
range, was that best suited to the circumstances, although had all anti- 
aircraft batteries been manned in advance, the total damage inflicted on  
ships would have been lessened to a minor extent and to a degree which  
is problematical; and that, had the Fleet patrol planes, slow and  
unsuited for aerial combat, been in the air, they might have escaped and  
the number of these planes lost might thus have been reduced.  
 
The Court is of the opinion however, that only had it been known in  
advance that the attack would take place on 7 December, could there now  
be any basis for a conclusion as to the steps that might have been taken  
to lessen its ill effects, and that, beyond the fact that conditions  
were unsettled and that, therefore, anything might happen, there was  
nothing to distinguish one day from another in so far as expectation of  
attack is concerned.  
 
[7]  It has been suggested that each day all naval planes should have  
been in the air, all naval personnel at their stations, and all anti- 
aircraft guns manned. The Court is of the opinion that the wisdom of  
this is questionable when it is considered that it could not be known  
when an attack would take place and that, to make sure, it would have  
been necessary to impose a state of tension on the personnel day after  
day, and to disrupt the maintenance and operating schedules of ships and  
planes beginning at an indefinite date between 16 October and 7  
December.  
 
Based on Finding XII. The Court is of the opinion that, as no  
information of any sort was at any time either forwarded or received  
from any source which would indicate that Japanese carriers or other  
Japanese ships were on their way to Hawaii during November or December,  
1941, the attack of 7 December at Pearl Harbor, delivered under the  
circumstances then existing, was unpreventable and that when it would  
take place was unpredictable.  
 
Based on Finding XIII the Court is of the opinion that the action of the  
Commander-in-Chiefs Pacific Fleet, in ordering that no routine, long- 
range reconnaissance be undertaken was sound and that the use of Fleet  
patrol planes for daily, long-range, all-around reconnaissance was not  
possible with the inadequate number of Fleet planes available, and was  
not justified in the absence of any information indicating that an  
attack was to be expected in the Hawaiian area within narrow limits of  
time.  
 
Based on Finding XIV, the Court is of the opinion that the shore-based  
air warning system, an Army service under the direct control of the  
Army, was ineffective on the morning of 7 December, in that there was no  
provision for  
 
Page 399 
 
keeping track of planes in the air near and over Oahu, and for  
distinguishing between those friendly and those hostile and that,  
because of this deficiency, a flight of planes which appeared on the  
radar screen shortly after 0700 was confused with a flight of Army B-17s  
en route from California, and that the information obtained by Army  
radar was valueless as a warning, because the planes could not be  
identified as hostile until the Japanese markings on their wings came  
into view. 
 
Based on Finding XV, the Court is of the opinion that by far the  
greatest portion of the damage inflicted by the Japanese on ships in,  
Pearl Harbor was due to specially designed Japanese torpedoes, the  
development and existence of which was unknown to the United States.  
 
Based on Finding XVI, and particularly in view of the Chief of Naval  
Operations' approval of the precautions taken and the deployments made  
by Admiral Kimmel in accordance with the directive contained in the  
dispatch of 16 October 1941, the Court is of the opinion that Admiral  
Kimmel's decision, made [8] after receiving the dispatch of 24 November,  
to continue the preparations of the Pacific Fleet for war, was sound in  
the light of the information then available to him.  
 
Based on Finding XVII, the Court is of the opinion that, although the  
attack of 7 December came as a surprise, there were good grounds for the  
belief on the part of high officials in the State, War, and Navy  
Departments, and on the part of the Army and Navy in the Hawaiian area,  
that hostilities would begin in the Far East rather than elsewhere, and  
that the same considerations which influenced the sentiment of the  
authorities in Washington in this respect, support the interpretation  
which Admiral Kimmel placed upon the "war warning message" of 27  
November, to the effect that this message directed attention away from  
Pearl Harbor rather than toward it.  
 
Based on Findings XVIII and XIX, the Court is of the opinion that  
Admiral Harold R. Stark, U. S. N., Chief of Naval Operations and  
responsible for the operations of the Fleet, failed to display the sound  
judgment expected of him in that he did not transmit to Admiral Kimmel,  
Commander-in-Chief, Pacific Fleet, during the very critical period 26  
November to 7 December, important information which he had regarding the  
Japanese situation and especially in that, on the morning of 7 December,  
1941, he did not transmit immediately the fact that a message had been  
received which appeared to indicate that a break in diplomatic relations  
was imminent, and that an attack in the Hawaiian area might be expected  
soon.  
 
The Court is further of the opinion that, had this important information  
been conveyed to Admiral Kimmel, it is a matter of conjecture as to what  
action he would have taken.  
 
Finally, based upon the facts established, the Court is of the opinion  
that no offenses have been committed nor serious blame incurred on the  
part of any person or persons in the naval service.  
 
[9] Fleet Admiral Ernest J. King, USN, commented in detail on the  
findings of the Court of Inquiry in the Second Endorsement thereto. He  
concluded, in part:  
 
Despite the evidence that no naval officer was at fault to a degree  
likely to result in conviction if brought to trial, nevertheless the  
Navy cannot evade a share of responsibility for the Pearl Harbor  
incident. That disaster cannot be regarded as an "act of God," beyond  
human power to prevent or mitigate. It is true that the country as a  
whole is basically responsible in that the people were unwilling to  
support an adequate army and navy until it was too late to repair the  
consequences of past neglect in time to deal effectively with the attack  
that ushered in the war. It is true that the Army was responsible for  
local defense at Pearl Harbor. Nevertheless, some things could have been  
done by the Navy to lessen the success of the initial Japanese blow.  
Admiral Stark and Admiral Kimmel were the responsible officers, and it  
is pertinent to examine the possible courses of action they might have  
taken.  
 
(a) Admiral Stark was, of course, aware that the United States was  
primarily concerned with its own possession, and the most important  
United States possessions in the Pacific were the Philippine Islands and  
the Hawaiian Islands his attention should have been centered on those  
two places, as the Pacific situation became more and more acute. He had  
been informed by Admiral Kimmel, in his letter of 26 May 1941, that  
Admiral Kimmel felt the need for  
 
Page 400 
 
early and accurate information as to the general situation, and that he  
needed to be informed of all important developments as they occurred by  
the quickest and most secure means available. This letter should have  
emphasized the obvious fact that Admiral Kimmel was in a difficult  
position, that he had to use his initiative to keep his Fleet  
dispositions in step with changes in the situation, and that in order to  
do so he had to have an accurate running picture of the rapidly moving  
course of diplomatic events. In my opinion, Admiral Stark failed to give  
Admiral Kimmel an adequate summary of the information available in  
Washington, particularly in the following respects:  
 
(1) Admiral Kimmel was not informed of the State Department's note of 26  
November to the Japanese. This note was a definite step towards breaking  
relations. 
 
(2) Admiral Kimmel was not informed of the substance of certain  
intercepted Japanese messages inquiring as to dispositions of ships  
inside Pearl Harbor, which indicated a Japanese interest in Pearl Harbor  
as a possible target.  
 
(3) Admiral Kimmel was not informed of the implementation of the "Winds  
message". Admiral Stark says he never got this information himself, but  
it is clear that it [10] did reach Admiral Stark's office. This,  
together with the handling of other matters of information, indicates  
lack of efficiency in Admiral Stark's organization.  
 
(4) Admiral Stark failed to appreciate the significance of the "1:00 p.  
m. message" received on the morning of 7 December, although the  
implications were appreciated by at least one of his subordinates. It  
appears that had this message been handled by the quickest available  
means, and with due appreciation of its significance, it might have  
reached Admiral Kimmel in time to enable him to make some last minute  
preparations that would have enhanced the ability of the ships in Pearl  
Harbor to meet the Japanese air attack.  
 
(5) There is a certain sameness of tenor of such information as Admiral  
Stark sent to Admiral Kimmel. They do not convey in themselves the sense  
of intensification of the critical relations between the United States  
and Japan.  
 
(b) In my opinion Admiral Kimmel, despite the failure of Admiral Stark  
to keep him fully informed, nevertheless did have some indications of  
increasing tenseness as to relations with Japan. In particular, he had  
the "war warning" message on 27 November, the "hostile action possible  
at any moment" message on 28 November, the 3 December message that  
Japanese had ordered destruction of codes, and the messages of 4 and 6  
December concerning destruction of United States secret and confidential  
matter at outlying Pacific Islands. These messages must be considered in  
connection with other facets of the situation, and Admiral Kimmel's  
statement on this phase of the matter must be given due consideration.  
After weighing these considerations, I am of the opinion that he could  
and should have judged more accurately the gravity of the danger to  
which the Hawaiian Islands were exposed. The following courses of action  
were open to him: 
 
(1) He could have used patrol craft which were available to him to  
conduct long range reconnaissance in the more dangerous sectors. Whether  
or not this would have resulted in detecting the approach of the  
Japanese carriers is problematical However, it would have made the  
Japanese task more difficult.  
 
(2) He could have rotated the "in port" periods of his vessels in a less  
routine manner, so as to have made it impossible for the Japanese to  
have predicted when there would be any vessels in port. This would have  
made the Japanese task less easy.  
 
[11] (3) If he had appreciated the gravity of the danger even a few  
hours before the Japanese attack, it is logical to suppose that naval  
planes would have been in the air during the early morning period, that  
ships' batteries would have been fully manned, and that damage control  
organizations would have been fully operational.  
 
The derelictions on the part of Admiral Stark and Admiral Kimmel were  
faults of omission rather than faults of commission. In the case in  
question, they indicate lack of superior judgment necessary for  
exercising command commensurate with their rank and their assigned  
duties, rather than culpable inefficiency. 
 
D. Army Pearl Harbor Report.  
 
Pursuant to Public Law No. 339, 78th Congress, an Army Board conducted  
investigation into the Japanese attack, and on 20 October 1944 submitted  
its report to the Secretary of War. The Army report  
 
Page 401 
 
discussed, among other things, various matters involving the Navy, such  
as the Navy's command relationships at Hawaii the "tapping" of the  
telephone wires of the Japanese Consul in Hawaii by Naval Intelligence,  
information secured by Navy radio intelligence as to the location and  
movements of Japanese naval forces, the Navy's responsibility for long  
range reconnaissance ("The heart of the defense of Oahu"), and the  
entrance of Japanese submarines into Pearl Harbor on and allegedly prior  
to 7 December 1941. The Army report commented critically as to (a) the  
Navy's failure to conduct long range reconnaissance, (b) the Navy's  
failure to advise General Short of the presence of a Japanese task force  
in the Jaluits in late November 1941, (c) the Navy's failure to advise  
General Short of certain messages, relating to the destruction of codes  
by the Japanese during the first week of December 1941, and (d) the  
Navy's failure to advise General Short of the sinking of a Japanese  
submarine on the morning of 7 December 1941, prior to the air attack.  
The Army report included a finding that relations between General Short  
and Admiral Kimmel were not satisfactory, as a practical matter,  
although cordial. Concerning intelligence generally, the Army report  
stated, at page 232: 
 
"The Japanese armed forces knew everything about us. We knew little  
about them. This was a problem of all our intelligence agencies. This  
should not come to pass again. Our intelligence service must be brought  
in line with the part which we are to play in world affairs.  
 
"We must know as much about other major world powers as they know about  
us. This is an absolute condition precedent to intelligent planning by  
those charged with formulating our international policies and providing  
for our security. Our intelligence service should be second to none in  
its efficiency. It must not be inferred that this is the exclusive  
function of the M. I. D. It is a national problem.  
 
"[12] In the past our intelligence service has suffered from lack of  
funds, lack of interest, and legal obstacles and regulations. Steps  
should be taken to correct all of these." 
 
After consideration of the Army Pearl Harbor Report, Fleet Admiral King,  
in a letter to the Secretary of the Navy, dated 3 December, 1944, stated  
in part:  
 
"The Army Board find it difficult to understand the relations between  
the Commander in Chief of the Pacific Fleet, the Commander Hawaiian Sea  
Frontier, the Commandant, FOURTEENTH Naval District, and the local Air  
Commander (Rear Admiral Bellinger). The Board makes the comment the Army  
had a difficult time in determining under which of the three shells  
(Kimmel, Bloch, or Bellinger) rested the pea of performance and  
responsibility." My comment as to this is that there are some  
unavoidable complexities in the Command relationships between a fleet, a  
frontier, and a fleet base in the frontier. However in this case, there  
was no possibility of misunderstanding the fact that all naval forces  
were under Admiral Kimmel. He and General Short should have been able to  
work out better arrangements for cooperation than they did. The reasons  
why they did not have been discussed in paragraphs 4 and 5 above.  
 
"The Army Board stresses the point that General Short was dependent upon  
the U. S. Navy for information as to what the Japanese Navy was doing  
and for estimates of what the Japanese Navy could do. This view is  
obviously sound. It was a naval responsibility to keep not only General  
Short but also the War Department fully acquainted with the estimate of  
the Japanese naval situation. There was some failure to pass on to  
General Short and the War Department information which should have been  
given to them by the Navy, but the basic trouble was that the Navy  
failed to appreciate what the Japanese Navy could, and did, do." 
 
The Army Board reports on three matters which should be further  
investigated by the Navy. These are:  
 
"a. It was stated that the War Department received information from some  
naval agency that on or about 25 November radio intercepts had located a  
Jap- 
 
Page 402 
 
anese task force, including carriers, in the Marshall Islands. About 1  
December it was reported that this force assumed radio silence. It is  
noted in the Record that this information never got to General Short.  
There is some reference to this incident in the Record of the Naval  
Court. But it was not followed up, presumably because the officer who  
was Director of Naval Intelligence at the time was not called as a  
witness. The matter is probably not of importance, since even if there  
actually was a Japanese force in the Marshalls it apparently had nothing  
to do with the attack on Pearl Harbor. However, for the sake of  
completing the naval Record, this matter should be pursued further.  
 
"[13]  b. The Army Board is of the opinion that Japanese midget  
submarines operated freely inside of Pearl Harbor for several days prior  
to the 7th of December for the purpose of obtaining information. This  
opinion is based on the testimony of an official of the Federal Bureau  
of Investigation, who apparently reached his conclusions by a study of  
certain captured Japanese charts which were made available to F. B. I.  
by Naval Intelligence. So far as is known, there is no real ground for  
the supposition that Japanese submarines were able to roam around Pearl  
Harbor at will, but since the allegation is made in the Army Record, it  
is advisable to clear up any doubt that may exist by further naval  
investigation.  
 
"c. There is reference to the fact that information was obtained from  
naval and F. B. I. espionage over telephones and cables in Hawaii, but  
no record of what this information was. This should be cleared up.  
 
"The Army Board finds that the Chief of Staff of the Army was at fault  
in that he failed to keep General Short informed of the international  
situation and that he delayed in getting critical information to General  
Short. In these respects, the Army Report parallels the Naval Court  
findings as to the Chief of Naval Operations. The Army Board further  
finds that General Marshall was at fault and that he failed to keep his  
Deputies informed of what was going on, so that they could act  
intelligently in his absence; in that he did not take action on General  
Short's report on 28 November that he had established "Alert No. 1.";  
and in that he lacked knowledge of conditions of readiness in the  
Hawaiian Command.  
 
"The Army Board finds that General Short was at fault in that he failed  
to place his command in an adequate state of readiness (the information  
which he had was incomplete and confusing, but it was sufficient to warn  
him of tense relations), in that he failed to reach an agreement with  
local naval officials for implementing joint Army and Navy plans and  
agreements for joint action, in that he failed to inform himself of the  
effectiveness of the long-distance reconnaissance being conducted by the  
Navy, and in that he failed to replace inefficient staff officers.  
 
"I find nothing in the Record of the Army Board to cause me to modify  
the opinions expressed in my endorsement on the Record of the Naval  
Court of Inquiry, except in relation to the cooperation between Admiral  
Kimmel and General Short. In view of the extensive and explicit  
discussion of this phase of the matter by the Army Board, I am no longer  
of the opinion that cooperation between these two officers was adequate  
in all respects. The cordial, but informal, contact which they  
maintained evidently was not sufficient to coordinate the means at their  
disposal to the best advantage. However, as already pointed out, this  
fault was part and parcel of the [14] general blindness to Japanese  
potentialities in the Central Pacific which was the basic cause of the  
Pearl Harbor disaster. The many details discussed by the Army Board and  
the Naval Court are useful in showing how this blindness redounded to  
our disadvantage, but they do not, in my opinion, prove anything more  
than that the two naval officers in the high commands concerned-Admiral  
Stark and Admiral Kimmel-failed to display the superior judgment they  
should have brought to bear in analyzing and making use of the  
information that became available to them.  
 
"I recommend that the Secretary of the Navy cause further investigation  
to be made in the matter referred to in paragraph 8 above; namely, the  
alleged radio contact with a Japanese force in the Marshall Islands, the  
alleged presence of Japanese midget submarines inside Pearl Harbor prior  
to 7 December, and the substance of information obtained by naval and F.  
B. I. telephone and cable intercepts. I do not think it necessary to  
reconvene the Court for this purpose. The proposed investigation could  
be made by another Court, or by an investigating: officer, for  
attachment to the Record of the original Court of Inquiry." 
 
Page 403 
 
E. Findings of the Secretary of the Navy and Further Investigation. 
 
Upon review of the previous investigations, the Secretary of the Navy  
found that there were errors of judgment on the part of certain officers  
in the Naval Service, both at Pearl Harbor and at Washington. The  
Secretary further found that the previous investigations had not  
exhausted all possible evidence and that the investigation directed by  
Public Law 339 of the 78th Congress should be continued until the  
testimony of every witness in possession of material facts should be  
obtained and all possible evidence exhausted. The Secretary stated that  
his decision would be reviewed when the investigation was finally  
completed, in the light of the evidence then at hand.  
 
The precept of the Secretary of the Navy, dated 2 May 1945, and amended  
6 July 1945, directed that Admiral H. Kent Hewitt, USN, make a study of  
the previous investigations, that such further investigation as might  
appear to be necessary be then conducted, and that upon completion a  
report be submitted to the Secretary of the Navy setting forth the  
findings and conclusions reached. 
 
Review of the previous investigations disclosed that various matters of  
importance, principally concerning intelligence, had not been  
investigated thoroughly. The subjects proposed for further investigation  
were approved by the Secretary of the Navy on 21 May 1945.  
 
Counsel in this investigation was John F. Sonnett, Special Assistant to  
the Secretary of the Navy. Also assisting were Lieutenant Commander  
Benjamin H. Griswold, III, USNR, and Lieutenant John Ford Baecher, USNR.  
The reporters were Ship's Clerk Ben Harold, USNR, and Chief Yeoman  
Raymond E. Reese, USNR. These men took a special oath to maintain the  
security of the information developed during the investigation.  
 
[15]

F. Witnesses in this Investigation. 
 
At Pearl Harbor in 1941: 
 
Captain Edwin T. Layton, USN, Intelligence Officer, Pacific Fleet. (R.  
182) 
 
Captain Joseph J. Rochefort, USN, in charge of Communications  
Intelligence Unit, Fourteenth Naval District. (R. 43; 541) 
 
Vice Admiral William W. Smith, USN, Chief of Staff, CincPac. (R. 335) 
 
Vice Admiral Charles H. McMorris, USN, War Plans Officer, CincPac. (R.  
293) 
 
Rear Admiral Walter S. DeLany, USN, Assistant Chief of Staff,  
Operations, CincPac. (R.163) 
 
Vice Admiral Patrick N. L. Bellinger. USN, Commander, Hawaiian Based  
Patrol Wings, Commander, Patrol Wing Two, Commander, Task Force Nine,  
Commander, Fleet Air Detachment, Pearl Harbor. (R. 471)  
 
Captain John B. Earle, USN, Chief of Staff, 14th N. D. (R. 451)  
 
Mr. George Street, Manager, RCA, Honolulu. (R. 411) 
 
Rear Admiral Irving H. Mayfield, USN, District Intelligence Officer,  
14th N. D. (R. 554)  
 
Captain Thomas H. Dyer, USN, Cryptanalytical and Decrypting, Fleet Radio  
Unit, Pacific Fleet. (R. 418) 
 
Captain Joseph Finnegan USN, Translator, Fleet Radio Unit, Pacific  
Fleet. (R. 424)  
 
Page 404 
 
Commander Wesley A. Wright, USN, Assistant Communications Officer,  
CincPac, on temporary duty with Com 14 Communications Intelligence Unit.  
(R. 442)  
 
Lieutenant (jg) Farnsley C. Woodward, USN, Cryptanalyst, Communications  
Intelligence Unit, 14th N. D. (R. 541)  
 
[16] Colonel Alva B. Yaswell, USMC, Translator, Communications  
Intelligence Unit, 14th N. D. (R. 541)  
 
Captain William W. Outerbridge, USN, Commanding Officer, USS WARD. (R.  
87)  
 
Lieutenant Commander Monroe H. Hubbell, USNR, Commanding Officer, USS  
CONDOR. (R. 428)  
 
Richard W. Humphrey, RM3c, USNR, Bishop's Point Radio Station.  
 
Lieutenant Oliver H. Underkofler, USSR, Communications Office, 14th N.  
D. (R. 465)  
 
Lieutenant Donald Woodrum, USNR, District Intelligence Office, 14th N.  
D. (R. 376)  
 
Commander Harold S. Burr, USNR. Com 14 Liaison Officer at General  
Short's Headquarters. (R. 376)  
 
Brigadier General Carroll A. Powell, USA, Signal Officer, Hawaiian  
Department. (R. 387) 
 
At the Philippines in 1941: 
 
Captain Redfield Mason, USN, Fleet Intelligence Officer, Asiatic Fleet.  
(R. 68)  
 
Commander Rudolph J. Fabian, USN, Officer in Charge, Radio Intelligence  
Unit, Corregidor. (R. 68)  
 
At Washington, D. C. in 1941. 
 
Vice Admiral Theodore S. Wilkinson, USN, Director of the Office of Naval  
Intelligence. (R. 389)  
 
Captain Arthur H. McCollum, USN. In charge of Far Eastern Section,  
Foreign Branch, ONI. (R. 10)  
 
Captain Laurance F. Safford, USN, Communications Security Section. (R.  
97; R. 529)  
 
Captain Alwin D. Kramer, USN, ONI and Communications Security Section.  
(R. 128)  
 
Mrs. Dorothy Edgers. Research Analyst, ONI. (R. 511)  
 
[17] Lieutenant Commander Francis M. Brotherhood, USNR. Communications  
Security Section. (R. 143)  
 
Lieutenant Frederick L. Freeman, USN, Communications Security Section.  
(R. 149)  
 
Lieutenant Commander Allan A. Murray, USNR, Communications Security  
Section. (R. 433).  
 
Lieutenant Commander George W. Linn, USNR, Communications Security  
Section. (R. 140) 
 
Lieutenant Commander Alfred V. Pering, USNR. Communications Security  
Section. (R. 148)  
 
Other witnesses: 
 
Captain William H. Smedberg, III, USN, Now Assistant Combat Intelligence  
Officer, Staff, Cominch. (R. 4)  
 
Lieutenant Commander Leo Reierstad, USNR, Now in charge of a translating  
unit of Op-16-FE. (R. 158)  
 
Lieutenant (jg) Joseph M. Conant, USNR, Translation sub-section head in  
Op-16-FE. (R. 158) 
 
Page 405 
 
Commander Walter Karig, USNR, Lieutenant Welbourn Kelley, USNR, Authors  
of "Battle Report." (R. 80) 
 
Lieutenant Commander Gilbert E. Boone, USNR Head of Op-20-GL. (R. 554;  
R. 607) 
 
[18]

G. Exhibits Received in this Investigation.  
 
Received in this investigation were the following exhibits:  
 
Num-  Description                                                 Record 
ber                                                                 Page 
   1 Precept convening investigation ...............................   1 
  1A Modification of precept, directing report of findings and 
     conclusions ................................................... 575 
   2 Narrative statement by counsel of previous Navy  
     investigations ................................................   2 
   3 CinCPOA Weekly Confidential Intelligence Bulletin of 8  
     December 1944, relating to the attacking force ................   5 
   4 A translation of a captured Japanese submarine chart, showing 
     courses and location of U. S. Ships in Pearl Harbor ...........   8 
   5 CinCPOA Confidential Intelligence Bulletin of 20 October 1944, 
     containing description of Japanese midget submarines ..........   9 
   6 ONI document "ONI 220-J, Japanese Submarines" .................   9 
   7 Berthing plan at Pearl Harbor, 7 December 1941 (Ex. 60 of Naval 
     Court) ........................................................   9 
   8 Photostatic copies of Com14 and Com16 dispatch estimates of 
     Japanese fleet location and movements, 26 November 1941 .......  12 
   9 ONI Bulletin of 1 December 1941. Japanese fleet locations .....  17 
  10 McCollum memorandum estimating situation as of 1 December  
     1941 ..........................................................  21 
  11 "Battle Report" ...............................................  22 
  12 FCC radio intercepts regarding "winds" code (Ex. 65 of Naval 
     Court) ........................................................  31 
  13 Collection of intercepted Japanese dispatches .................  56 
 14A-D (Photostatic copies of captured Japanese submarine chart,  
     showing courses and location of U s ships in Pearl Harbor .....  60 
  15 Collection of intercepted Japanese dispatches (Ex. 63 of Naval 
     Court) ........................................................  66 
  16 Copies of dispatches sent from RI unit, Corregidor, regarding 
     Japanese fleet movements ......................................  75 
  17 Photostat of captured Japanese submarine chart used for  
     Plate V of "Battle Report" ....................................  83 
[19] 
  18 Log of conversation between WARD and CONDOR on the morning of 7 
     December 1941 .................................................  91 
  19 Tentative copies of Communication Intelligence Summaries, for 
     1 November, 1941 to 6 December 1941, at Pearl Harbor .......... 103 
  20 Message from Tokyo establishing the hidden word code .......... 135 
  21 Pacific Fleet Intelligence Bulletin of 27 November 1941  
     concerning composition of Japanese Navy ....................... 185 
  22 Daily Communication Intelligence Summaries, 14 October 1941 to 
     5 December 1941, given to Fleet Intelligence Officer (Captain 
     Layton) for delivery to Admiral Kimmel ........................ 194 
  23 Memorandum of 1 December 1941 from Fleet Intelligence Officer 
     to Admiral Kimmel, estimating Japanese ship locations ......... 211 
  24 November 24th dispatch from CNO to CincPac  
     (Ex. 15 of Naval Court) ....................................... 238 
  25 "War Warning" (Ex 17 of Naval Court) .......................... 247 
  26 Layton Intelligence reports from 6 October 1941 to  
     2 December 1941 ............................................... 259 
  27 Paraphrased copies of dispatches from various intelligence  
     agencies delivered to CincPac ................................. 264 
  28 Memorandum from Fleet Intelligence Officer to Admiral Kimmel 
     regarding proposed Army aerial reconnaissance of Mandated 
     Islands ....................................................... 266 
  29 Intercepted Japanese consular dispatches delivered to Fleet 
     Intelligence Officer about December 10th ...................... 272 
  30 Two Japanese panorama views of Pearl Harbor with Japanese log  
     on reverse side, recovered from submarine  
     (returned to Captain Layton) .................................. 279 
 30A Photostat of Japanese log on reverse of exhibit 30 ............ 279 
 30B Translations of exhibits 30 and 30A ........................... 280 
  31 Panorama sketch of Pearl Harbor from position five miles south 
     of Pearl Harbor, recovered from submarine 
     (returned to Captain Layton) .................................. 280 
 31A Photostats of exhibit 31 ...................................... 280 
  32 Original Japanese chart of Pearl Harbor recovered from Japanese 
     midget submarine 
     (returned to Captain Layton) .................................. 281 
[20] 
 32A Photostat of exhibit 32 ....................................... 281 
  33 Original Japanese chart of Pearl Harbor recovered from Japanese 
     submarine, showing defensive installations 
     (returned to Captain Layton) .................................. 290 
 33A Photostatic copy of exhibit 33 ................................ 291 
  34 Staff Instructions, CincPac, 1941 ............................. 293 
  35 U. S. Pacific Fleet Operating Plan, Rainbow Five 
     (Navy Plan O-1, Rainbow Five) (WPPac 46) ...................... 295 
  36 Letter of 9 September 1941 from CNO to CincPac, approving  
     Pacific Fleet Operating Plan Rainbow Five ..................... 297 
 36A Letter of 25 July 1941 from CincPac to CNO, submitting Pacific  
     Fleet Operating Plan Rainbow Five ............................. 297 
  37 Photostatic copy of schedules setting forth utilization of  
     patrol planes of Pacific Fleet from 17 November to 31 December  
     and approved 22 November 1941 ................................. 368 
 
Page 406 
 
Num-  Description                                                 Record 
ber                                                                 Page 
  38 Transcripts of intercepted telephone calls of Japanese Consul  
     and Vice Consul in Honolulu from October to 2 December 1941 
     (Consul's marked 38A; Vice Consul's marked 38B) ............... 379 
  39 Copy of intercepted "Mori conversation" ....................... 382 
  40 ONI Summaries of messages sent by Japanese Consul in Honolulu  
     from 1 December to 6 December 1941 ............................ 385 
  41 File of work sheets on Jap diplomatic traffic (incorporated in 
     other exhibit) ................................................ 420 
  42 Paper showing part of decryption process of Japanese  
     "PA" code ..................................................... 421 
  43 Duty Officer, Navy Yard, Pearl Harbor, information sheets ..... 430 
  44 Extract from signal log of gate vessel of 7 December 1941 ..... 430 
  45 Extract from quartermaster's log of gate vessel of  
     7 December 1941 ............................................... 431 
  46 Extract from log of Signal Tower, Navy Yard, Pearl Harbor,  
     of 7 December 1941 ............................................ 432 
  47 Collection of documents, containing Annex VII, Section VI,  
     Joint Agreements, to Joint Coastal Frontier Defense Plan ...... 457 
  48 Collection of dispatches regarding submarine contacts at Pearl  
     Harbor in November and December, 1941 ......................... 461 
  49 Bellinger "Estimate of Situation" ............................. 474 
[21] 
  50 Letter from ComTaskFor 9. To CinC, 20 December 1941, on 
     reconnaissance prior to attack ................................ 481 
 50A Dispatches cited in exhibit 50 ................................ 482 
  51 ComTaskFor 9 letter of 22 October 1941, file 0026 ............. 483 
  52 ComTaskFor 9 letter of 16 January 1941 ........................ 484 
  53 ComPatWing 2 letter to CNO, of 11 December 1940 ............... 488 
  54 Watch and duty schedules of Patrol Wings One and Two prior to 
     attack ........................................................ 496 
  55 RCA Communications, Inc., statement listing certain Japanese 
     cable messages from Honolulu in November and December 1941 .... 542 
  56 Coded messages from Japanese Consul General at Honolulu,  
     via RCA, among those listed in exhibit 55, received by Navy  
     5 December 1941 ............................................... 544 
 56A Pages 7 to 12 of exhibit 56, containing messages not decrypted 
     until after the attack ........................................ 600 
  57 Coded messages from Japanese Consul General at Honolulu, 
     via RCA, among those listed in exhibit 55, received by Navy  
     after the attack .............................................. 550 
 57A Coded messages from Japanese Consul General at Honolulu,  
     via RCA, received by Navy on night of 7 December and  
     subsequently translated ....................................... 601 
  58 Collection of dispatches from Naval Communication files  
     relating to Japanese fleet movements and locations during the 
     period 27 November to 7 December 1941 ......................... 555 
  59 Collection of Japanese plain language news broadcasts ......... 555 
  60 Collection of memoranda relating to messages received at Naval 
     Communications in various Japanese code systems ............... 556 
  61 Memorandum of Naval Communications, surveying work sheets  
     processed by Navy of Japanese purple system ................... 557 
  62 Report from DIO, 14th N. D., to Director of Naval Intelligence, 
     of 19 April 1942, relating to coded dispatch traffic of  
     Japanese Consul General, Honolulu ............................. 569 
  63 Certified collection of documents relating to anti-torpedo  
     baffles for protection against torpedo plane attacks .......... 602 
  64 Copy of ltr. from Secretary of War to Secretary of Navy, dated 
     7 February 1941, relating to air defense at Pearl Harbor ...... 603 
[22] 
  65 CincPac Secret letter of 7 August 1941 relating to the 
     organization of the Orange fleet .............................. 601 
  66 Map showing the location of ships present at Pearl Harbor on  
     7 December 1941 ............................................... 603 
  67 Telephone log of radio unit at Pearl Harbor, showing calls  
     made and received on 7 December 1941 as to Jap fleet 
     locations ..................................................... 603 
  68 Photostatic copies of memoranda relating to questioning of  
     captain of Japanese captured submarine ........................ 604 
  69 Pacific Fleet Weekly Intelligence Bulletin for 11 June 1945,  
     containing description of midget submarines and method of  
     transport to Pearl Harbor ..................................... 604 
  70 Selected collection of Pearl Harbor dispatches, miscellaneous  
     subjects, taken from CincPac Headquarters ..................... 604 
  71 Collection of dispatches relating to proposed Army  
     reconnaissance in November of 1941 ............................ 604 
  72 Collection of dispatches of December 7 and 8,1941,  
     from CincPac .................................................. 605 
  73 CincPac Secret letter of 12 December 1941 reporting damage to 
     ships at Pearl Harbor as result of attack and other details ... 605 
  74 Photostatic copy of War Diary of Com 14 from 7 December 1941 
     to 1 January 1942 ............................................. 605 
  75 War Diary of USS WARD, War Diary of O-in-C, Net and Boom  
     Defenses, 14th N. D.; War Diary of USS CONDOR; excerpts from 
     diary of O-in-C, Net and Boom Defenses, 14th N. D., WARD, and 
     CONDOR ........................................................ 605 
  76 Photostatic copy of 1st and 2nd endorsements on Com 14 letter  
     of 30 December 1941 relating to early morning submarine contact 
     on 7 December 1941 ............................................ 606 
  77 Collection of correspondence relating to combined operating  
     center for Army and Navy ...................................... 606 
  78 Typewritten translation and copy of intercepted Japanese 
     communication contained in exhibit 20, and notes relating 
     thereto ....................................................... 611 
  79 Photostatic copy of page 44 of volume containing translations of  
     files of operations orders, memos, and serials dealing with  
     Japanese Navy plans, recovered from Jap CA NACHI .............. 613 
  80 Joint Coastal Frontier Defense, Plan Hawaiian Theatre ......... 613 
  81 Collection of photostatic copies of ONI memoranda dealing with 
     organization and locations of Jap fleet as estimated during 
     November and up to December 1, 1941 ........................... 613 
 
Page 407 
 
[23] I 
 
THE WAR AND DEFENSE PLANS 
 
A. U. S. Pacific Fleet Operating Plan Rainbow Five.  
 
On 26 July 1941, U. S. Pacific Fleet Operating Plan Rainbow Five  
(Exhibit 35) was distributed to the Pacific Fleet by Admiral Kimmel.  
This plan was designed to implement the Navy basic war plan (Rainbow  
Five) in so far as the tasks assigned the U. S. Pacific Fleet were  
concerned. It was approved 9 September 1941 by the Chief of Naval  
Operations (Exhibit 36). The plan provided in part:  
 
[Begin quote, ending at "B." on page 411. LWJ] 
 
INTRODUCTION 
 
CHAPTER IV. MOBILIZATION 
 
0401. At the date of issue of this plan, the U. S. Pacific Fleet has  
virtually mobilized, and is operating, with intensive security measures  
from the Pearl Harbor base. It is expected, therefore, that the major  
portion of the Fleet can be ready for active service within four days of  
an order for general mobilization. To provide for the contingency of M- 
day being set prior to the date on which hostilities are to open, the  
day of execution of this Plan is designated throughout the Plan as W- 
day. The day that hostilities open with Japan will be designated J-day.  
This may or may not coincide with W-day.  
 
CHAPTER II. ASSUMPTIONS 
 
1211. The general assumptions on which this Plan is based are:  
 
a. That the Associated Powers, comprising initially the United States,  
the British Commonwealth (less Eire), the Netherlands East Indies, the  
Governments in Exile, China, and the 'Free French' are at war against  
the Axis powers, comprising either 
 
1. Germany, Italy, Roumania, Hungary, Bulgaria, or  
 
2. Germany, Italy, Japan, Roumania, Hungary, Bulgaria, and Thailand.  
 
NOTE: As of 22 June war exists between the European Axis and Russia, and  
the latter may be tentatively considered as an ally against that part of  
the Axis but not necessarily against Japan....  
 
[24] CHAPTER III. INFORMATION 
 
1314. The concept of the war in the Pacific, as set forth in ABC-1 is as  
follows:  
 
Even if Japan were not initially to enter the war on the side of the  
Axis Powers, it would still be necessary for the Associated Powers to  
deploy their forces in a manner to guard against Japanese intervention.  
If Japan does enter the war, the military strategy in the Far East will  
be defensive. The United States does not intend to add to its present  
military strength in the Far East but will employ the United States  
Pacific Fleet offensively in the manner best calculated to weaken  
Japanese economic power, and to support the defense of the Malay barrier  
by diverting Japanese strength away from Malaysia. The United States  
intends to so augment its forces in the Atlantic and Mediterranean areas  
that the British Commonwealth will be in a position to release he  
necessary forces for the Far East.  
 
CHAPTER III. INFORMATION 
 
Section 3. Estimate of Enemy Action 
 
1331. It is believed that German and Italian action in the Pacific will  
be limited to commerce raiding with converted types, and possibly with  
an occasional pocket battleship or heavy cruiser. 
 
1332. It is conceived that Japanese action will be as follows:  
 
a. The principal offensive effort to be toward the eventual capture of  
Malaysia (including the Philippines) and Hong Kong.  
 
b. The secondary offensive efforts to be toward the interruption of  
American and Allied sea communications in the Pacific, the Far East and  
the Indian Ocean, and to accomplish the capture of Guam and other  
outlying positions. 
 
Page 408 
 
c. The offensive against China to be maintained on a reduced scale only.  
 
d. The principal defensive efforts to be:  
 
1. Destruction of threatening naval forces.  
 
2. Holding positions for their own use and denying positions in the  
Central and Western Pacific and the Far East which may be suitable for  
advanced bases.  
 
[25] 3. Protecting national and captured territory and approaches.  
 
1333. To accomplish the foregoing it is believed that Japan's initial  
action will be toward:  
 
a. Capture of Guam.  
 
b. Establishment of control over the South China Sea, Philippine waters,  
and the waters between Borneo and New Guinea, by the establishment of  
advanced bases, and by the destruction of United States and allied air  
and naval forces in these regions, followed by the capture of Luzon.  
 
c. Capture of Northern Borneo.  
 
d. Denial to the United States of the use of the Marshall-Caroline- 
Marianas area by the use of fixed defenses, and, by the operation of air  
forces and light naval forces to reduce the strength of the United  
States Fleet.  
 
e. Reinforcement of the Mandate Islands by troops, aircraft and light  
naval forces.  
 
f. Possibly raids or stronger attacks on Wake, Midway and other outlying  
United States positions.  
 
1334. The initial Japanese deployment is therefore estimated to be as  
follows:  
 
a. Troops and aircraft in the Homeland, Manchukuo, and China with strong  
concentrations in Formosa and Hainan, fairly strong defenses in the  
Carolines, and comparatively weak but constantly growing defenses in the  
Marshalls.  
 
b. Main fleet concentration in the Inland Sea, shifting to a central  
position (possibly Pescadores) after the capture of Guam and the  
reinforcement of the Mandates.  
 
c. A strong fleet detachment in the Mindanao-Celebes area (probable main  
base in Halmahera).  
 
d. Sufficient units in the Japan Sea to counter moves of Russian Naval  
forces in that area.  
 
e. Strong concentration of submarines and light surface patrol craft in  
the Mandates, with such air scouting and air attack units as can be  
supported there.  
 
f. Raiding and observation forces widely distributed in the Pacific, and  
submarines in the Hawaiian area.  
 
[26] PART II. OUTLINE OF TASKS 
 
CHAPTER I. TASKS ASSIGNED BY NAVY BASIC PLAN-MISSION 
 
2101. The Navy Basic War Plan (Rainbow Five) assigns the following tasks  
within the Pacific Area to the U. S. Pacific Fleet:  
 
a. SUPPORT THE FORCES OF THE ASSOCIATED POWERS IN THE FAR EAST BY  
DIVERTING ENEMY STRENGTH AWAY FROM THE MALAY BARRIER, THROUGH THE DENIAL  
AND CAPTURE OF POSITIONS IN THE MARSHALLS, AND THROUGH RAIDS ON ENEMY  
SEA COMMUNICATIONS AND POSITIONS; 
 
b. PREPARE TO CAPTURE AND ESTABLISH CONTROL OVER THE CAROLINE AND  
MARSHALL ISLAND AREA, AND TO ESTABLISH AN ADVANCED FLEET BASE IN TRUK;  
 
c. DESTROY AXIS SEA COMMUNICATIONS BY CAPTURING OR DESTROYING VESSELS  
TRADING DIRECTLY OR INDIRECTLY WITH THE ENEMY; 
 
d. SUPPORT BRITISH NAVAL FORCES IN THE AREA SOUTH OF THE EQUATOR AS FAR  
WEST AS LONGITUDE 155  EAST; 
 
e. DEFEND SAMOA IN CATEGORY "D"; 
 
f. DEFEND GUAM IN CATEGORY "F"; 
 
g. PROTECT THE SEA COMMUNICATIONS OF THE ASSOCIATED POWERS BY ESCORTING,  
COVERING AND PATROLLING AS REQUIRED BY CIRCUMSTANCES, AND BY DESTROYING  
ENEMY RAIDING FORCES;  
 
h. PROTECT THE TERRITORY OF THE ASSOCIATED POWERS IN THE PACIFIC AREA  
AND PREVENT THE EXTENSION OF ENEMY MILITARY POWER INTO THE EASTERN  
HEMISPHERE BY DESTROYING HOSTILE EXPEDITIONS AND BY SUPPORTING LAND AND  
AIR FORCES IN DENYING THE ENEMY THE USE OF LAND POSITIONS IN THAT  
HEMISPHERE; 
 
Page 409 
 
CHAPTER II. TASKS FORMULATED TO ACCOMPLISH THE ASSIGNED MISSIONS 
 
2201. It will be noted that the tasks assigned in the previous chapter  
are based upon Assumption a2 of paragraph 1211 (Japan in the war). In  
formulating tasks the Commander-in-Chief has provided also for  
Assumption a1 and divides the tasks to be accomplished by the Pacific  
Fleet into phases, as follows:  
 
[27]  a. PHASE I.-Initial tasks-Japan not in the war.  
 
b. PHASE IA.-Initial tasks-Japan in the war.  
 
c. PHASE II, etc.-Succeeding tasks.  
 
2202. Phase I tasks are as follows:  
 
a. COMPLETE MOBILIZATION AND PREPARE FOR DISTANT OPERATIONS; THEREAFTER  
MAINTAIN ALL TYPES IN CONSTANT READINESS FOR DISTANT SERVICE.  
 
b. MAINTAIN FLEET SECURITY AT BASES AND ANCHORAGES AND AT SEA. 
 
c. TRANSFER THE ATLANTIC REINFORCEMENT, IF ORDERED. 
 
d. TRANSFER THE SOUTHEAST PACIFIC FORCE, IF ORDERED.  
 
e. ASSIGN TWELVE PATROL PLANES AND TWO SMALL TENDERS TO PACIFIC SOUTHERN  
AND A SIMILAR FORCE TO PACIFIC NORTHERN NAVAL COASTAL FRONTIER, ON M- 
DAY. 
 
f. ASSIGN TWO SUBMARINES AND ONE SUBMARINE RESCUE VESSEL TO PACIFIC  
NORTHERN NAVAL COASTAL FRONTIER ON M-DAY.  
 
g. PROTECT THE COMMUNICATIONS AND TERRITORY OF THE ASSOCIATED POWERS AND  
PREVENT THE EXTENSION OF ENEMY MILITARY POWER INTO THE WESTERN  
HEMISPHERE BY PATROLLING WITH LIGHT FORCES AND PATROL PLANES, AND BY THE  
ACTION OF STRIKING GROUPS AS NECESSARY. IN SO DOING SUPPORT THE BRITISH  
NAVAL FORCES SOUTH OF THE EQUATOR AS FAR WEST AS LONGITUDE 155  EAST.  
 
h. ESTABLISH DEFENSIVE SUBMARINE PATROLS AT WAKE AND MIDWAY.  
 
i. OBSERVE, WITH SUBMARINES OUTSIDE THE THREE MILE LIMIT THE POSSIBLE  
RAIDER BASES IN THE JAPANESE MANDATES, IF AUTHORIZED AT THE TIME BY THE  
NAVY DEPARTMENT. 
 
j. PROSECUTE THE ESTABLISHMENT AND DEFENSE OF SUBSIDIARY BASES AT  
MIDWAY, JOHNSTON, PALMYRA, SAMOA, GUAM AND WAKE AND AT CANTON IF  
AUTHORIZED. 
 
k. CONTINUE TRAINING OPERATIONS AS PRACTICABLE.  
 
l. MOVE THE MAXIMUM PRACTICABLE PORTION OF SECOND MARINE DIVISION TO  
HAWAII FOR TRAINING IN LANDING OPERATIONS.  
 
m. GUARD AGAINST SURPRISE ATTACK BY JAPAN.  
 
[28] Phase IA 
 
2203. Phase IA tasks are as follows:  
 
a. CONTINUE TASKS OUTLINED IN 2202 a, b, g, h, and k.  
 
b. ACCOMPLISH SUCH OF THE TASKS IN 2202 e, d, e, f, and j AS HAVE NOT  
BEEN COMPLETED.  
 
c. MAKE AN INITIAL SWEEP FOR JAPANESE MERCHANTMEN AND ENEMY RAIDERS AND  
TENDERS IN THE NORTHERN PACIFIC.  
 
d. CONTINUE THE PROTECTION OF THE TERRITORY AND COMMUNICATIONS OF THE  
ASSOCIATED POWERS, AND OF THE NAVAL. COASTAL FRONTIER FORCES, CHIEFLY BY  
COVERING OPERATIONS.  
 
e. 1. MAKE RECONNAISSANCE AND RAID IN FORCE ON THE MARSHALL ISLANDS.  
 
2. IF AVAILABLE CRUISERS AND OTHER CIRCUMSTANCES PERMIT, MAKE CRUISER  
RAIDS AGAINST JAPANESE SHIPPING IN WATERS BETWEEN NANSEI SHOTO AND NANPO  
SHOTO.  
 
f. ESTABLISH AND MAINTAIN MAXIMUM PRACTICABLE SUBMARINE PATROLS AGAINST  
JAPANESE FORCES AND COMMUNICATIONS NEAR THE JAPANESE HOMELAND.  
 
g. MAINTAIN AIR PATROLS AGAINST ENEMY FORCES IN THE APPROACHES TO OAHU  
AND OUTLYING BASES.  
 
h. ESCORT IMPORTANT SHIPPING, INCLUDING TROOP MOVEMENT BETWEEN THE  
HAWAIIAN AREA AND THE WEST COAST.  
 
l. ROUTE SHIPPING IN THE FLEET CONTROL ZONE WHEN ESTABLISHED.  
 
Page 410 
 
j. AUGMENT THE LOCAL DEFENSE FORCES OF THE HAWAIIAN NAVAL COASTAL  
FRONTIER AS NECESSARY.  
 
K. MOVE FROM SAN DIEGO TO HAWAII THE REMAINING UNITS AND EQUIPMENT OF  
THE SECOND MARINE DIVISION.  
 
1. PREPARE TO CAPTURE AND ESTABLISH CONTROL OVER THE MARSHALL ISLAND  
AREA.  
 
PART III. TASK ASSIGNMENT 
 
CHAPTER I. PHASE I 
 
Section 4. TASK FORCE NINE, (PATROL PLANE FORCE) 
 
3141. Task Force Nine will perform the tasks assigned in the following  
paragraphs of this section.  
 
[29] 3142. ON W-DAY TRANSFER TWELVE PATROL PLANES AND TWO TENDERS TO  
EACH OF THE PACIFIC SOUTHERN AND PACIFIC NORTHERN NAVAL COASTAL  
FRONTIERS. CONTINUE ADMINISTRATION OF THESE FORCES AND ROTATE DETAIL AT  
DISCRETION.  
 
3143. PERFORM TASKS ASSIGNED IN THE PATROL AND SWEEPING PLAN (ANNEX  
I).....  
 
"PART V. SPECIAL PROVISIONS 
 
CHAPTER IV. TENTATIVE OPERATION PLANS 
 
PHASES I AND IA 
 
Section 1. Phase I                       United States Pacific Fleet 
                                         U. S. S. PENNSYLVANIA, Flagship 
                                         Place 
                                         Date 
 
Operation Plan 
 
No. 1-R5." ....  
 
1. Information, Assumptions, etc., as previously given in Parts I, II  
and III of Navy Plan 0-1, Rainbow Five.  
 
2 This Fleet will, in the Pacific Area, protect the territory and sea  
communications of the Associated Powers and will support British Naval  
Forces south of the equator as far west as Longitude 155  East, while  
continuing training and guarding against attack by Japan.....  
 
Annex I 
 
                                         United States Pacific Fleet 
                                         U. S. S. PENNSYLVANIA, Flagship 
                                         Place 
                                         Date 
 
Patrol and Sweeping Plan" .... 
 
1. Information and Assumptions as previously given in Parts I, II, and  
III of this Navy Plan 0-1, Rainbow Five. Latest information of enemy  
dispositions, estimated intentions, and location of merchant shipping  
will be furnished by the Commander-in-Chief, U. S. Pacific Fleet, at  
time of execution.  
 
[30] 2. Phase I 
 
This Fleet will, in the Pacific Area, protect the territory and sea  
communications of the Associated Powers by:  
 
(a) Patrolling against enemy forces, particularly in the vicinity of the  
Hawaiian Islands; and on shipping lanes (1) West Coast-Hawaii, (2)  
Trans-Pacific westward of Midway and (3) in South Seas in vicinity of  
Samoa. 
 
(b) Escorting as conditions require and forces available permit.  
 
(c) Covering.  
 
(d) Employing striking forces against enemy raids and expeditions.  
 
(e) Routing shipping. . . .  
 
3. (d) Task Force Nine (Patrol Plane Force).  
 
(1) Having due regard for time required to overhaul and upkeep planes  
and for conservation of personnel, maintain maximum patrol plane search  
against enemy forces in the approaches to the Hawaiian area. 
 
Page 411 
 
(2) Initially base and operate one patrol plane squadron from Midway. At  
discretion increase the number of planes operating from bases to  
westward of Pearl Harbor to two squadrons, utilizing Johnston and Wake  
as the facilities thereat and the situation at the time makes  
practicable.  
 
(3) Be prepared, on request of Commander Task Force Three, to transfer  
one patrol squadron and tenders to that force for prompt operations in  
the South Pacific.  
 
(4) Be particularly alert to detect disguised raiders.  
 
(5) In transferring planes between bases, conduct wide sweep enroute.  
 
(6) Planes engaged in training operations furnish such assistance to  
Naval Coastal Frontiers in which based as may be practicable.  
 
[31]  (7) Effect closest cooperation practicable with surface forces  
engaged in sweeping during initial sweep of Phase IA.  
 
(8) Modify patrols as necessary in order to carry out tasks assigned in  
Marshall Raiding and Reconnaissance Plan (Annex II to Navy Plan O-1)....  
 
B. Joint Coastal Frontier Defense Plan, Hawaiian Theater, Orange 14ND- 
JCD-42.  
 
The Joint Coastal Frontier Defense Plan, Hawaiian Coastal Frontier,  
Hawaiian Department and FOURTEENTH Naval District (14ND-JCD-42) was  
signed and placed in effect on 11 April 1941 by the Commanding General,  
Hawaiian Department, and by the Commandant FOURTEENTH Naval District  
(Exhibit 80). The plan was based on the joint Army and Navy basic war  
plans, and was to constitute the basis on which all subsidiary peace and  
war projects, joint operating plans, and mobilization plans would be  
based. The method of coordination under the plan was by mutual  
cooperation which was to apply to all activities wherein the Army and  
the Navy would operate in coordination until and if the method of unity  
of command were invoked. The tasks assigned were as follows: 
 
14. TASKS.  
 
a. JOINT TASK. To hold OAHU as a main outlying naval base, and to  
control and protect shipping in the Coastal Zone.  
 
b. ARMY TASK. To hold OAHU against attacks by sea, land, and air forces  
and against hostile sympathizers; to support the naval forces.  
 
c. NAVY TASK. To patrol the Coastal Zone and to control and protect  
shipping therein; to support the Army forces.  
 
The Hawaiian Naval Coastal Zone was defined as "The Hawaiian Naval  
Coastal Zone comprises the waters of the Hawaiian Coastal Frontier"  
(Oahu and such adjacent land and sea areas as were required for the  
defense of Oahu).  
 
The plan provided that the Commanding general, Hawaiian Department, and  
the Commandant, FOURTEENTH Naval District, should provide for the  
following: 
 
17. ARMY . The Commanding General, HAWAIIAN DEPARTMENT, shall provide  
for:  
 
a. The beach and land, seacoast and antiaircraft defense of OAHU with  
particular attention to the PEARL HARBOR NAVAL BASE and naval forces  
present thereat, HONOLULU HARBOR, CITY OF HONOLULU, and the SCHOFIELD  
BARRACKS-WHEELER FIELD-LUALUALEI area. The increasing importance of the  
KANEOHE area is recognized.  
 
[32] b. An antiaircraft and gas defense intelligence and warning  
service.  
 
c. Protection of landing fields and naval installations on outlying  
islands consistent with available forces.  
 
d. Defense of installations on OAHU vital to the Army and Navy and to  
the civilian community for light, power, water, and for interior guard  
and sabotage, except within naval establishments.  
 
e. Defense against sabotage within the HAWAIIAN ISLANDS, except within  
naval shore establishments.  
 
Page 412 
 
f. Establishment of an inshore aerial patrol of the waters of the OAHU  
D. C. A., in cooperation with the Naval Inshore Patrol (see par. 18.  
A.), and an aerial observation system on outlying islands, and an  
Aircraft Warning service for the HAWAIIAN ISLANDS.  
 
g. Support of naval aircraft forces in major offensive operations at sea  
conducted within range of Army bombers.  
 
h. Provide personnel for and Army communication facilities to harbor  
control post provided for in paragraph 18. e. 
 
i. In conjunction with the Navy, a system of land communications  
(coordinated by means of teletype, telegraph loops, and radio  
intercepts, and detailed joint instructions) to insure prompt  
transmittal and interchange of hostile intelligence. Radio communication  
between the Army and the Navy will be governed by "Joint Army and Navy  
Radio Procedure, The Joint Board, 1940."  
 
j. An intelligence service, which, in addition to normal functions, will  
gather, evaluate, and distribute both to the Army and to the Navy,  
information of activities of enemy aliens or alien sympathizers within  
the HAWAIIAN ISLANDS.  
 
k. Counter-espionage within the HAWAIIAN ISLANDS.  
 
l. Control of dangerous aliens or alien sympathizers in the HAWAIIAN  
ISLANDS.  
 
m. Army measures to assure effective supervision, control, and  
censorship over communication systems which will conform to Joint Action  
of the Army and the Navy, 1935, Chapter IX.  
 
n. Supply of all Army and civil population in the HAWAIIAN ISLANDS.  
 
[33] o. Hospitalization of all Army and civil population in the HAWAIIAN  
ISLANDS.  
 
p. Reception and distribution of personnel and supplies for the Army and  
of supplies for the civil population.  
 
18. NAVY. The Commandant, FOURTEENTH NAVAL DISTRICT, shall provide for:  
 
a. An inshore patrol.  
 
b. An offshore patrol.  
 
c. An escort force.  
 
d. An attack force.  
 
e. Provide and maintain a harbor control post for joint defense of PEARL  
and HONOLULU HARBORS.  
 
f. Installation and operation of an underwater defense for PEARL, and  
HONOLULU HARBORS. (Hydro-acoustic posts, fixed, when developed and  
installed probably will be under cognizance of the Army.)  
 
g. Support of Army forces in the OAHU-D. C. A and installation of  
submarine mine fields in the defense of the OAHU-D. C. A. as may be  
deemed necessary and practicable.  
 
h. Sweeping channels and mine fields.  
 
i. Distant reconnaissance.  
 
j. Attacking enemy naval forces.  
 
k. Maintenance of interior guard and defense against sabotage within all  
naval shore establishments.  
 
l. In conjunction with the Army, as provided for in paragraph 17 i., a  
local communication service to insure prompt transmittal and interchange  
of intelligence.  
 
m. Navy measures to assure effective supervision, control and censorship  
over communication systems which will conform to Joint Action of the  
Army and the Navy, 1930, Chapter IX. 
 
n. Operation of a Naval intelligence system, including counter- 
espionage, for the collection, evaluation, and dissemination of hostile  
information. 
 
o. Supply and hospitalization of all local naval defense forces.  
 
[34] p. Operation or supervision of all water transportation and  
facilities pertaining thereto. 
 
C. Annex VII, Section. VI, to the Joint Coastal Frontier Defense Plan.  
 
Annex VII, Section VI to the Joint Coastal Frontier Defense Plan,  
Hawaiian Department and Fourteenth Naval District, dated 28 March 1941,  
and approved by Admiral Bloch and General Short 2 April 19417 (Exhibit  
47), dealt with joint security measures and 
 
Page 413 
 
protection of the Fleet and Pearl Harbor base. It stated that in order  
to coordinate joint defensive measures for the security of the Fleet and  
for the Pearl Harbor Naval base for defense against hostile raids or air  
attacks delivered prior to a declaration of war, and before a general  
mobilization for war, there were adopted the following agreements:  
 
Paragraph II, in respect of joint air operations, provided that when the  
(Commanding General and ComFOURTEEN agreed that the threat of a hostile  
raid or attack was sufficiently imminent to warrant such action, each  
commander would take such preliminary steps as were necessary to make  
available without delay to the other commander such proportion of the  
air forces at his disposal as circumstances warranted in order that  
joint operations might be conducted in accordance with the following  
plans: (a) joint air attacks upon hostile surface vessels to be  
conducted under the tactical command of the Navy; (b) defensive air  
operations over and in the immediate vicinity of Oahu to be executed  
under the tactical command of the Army; (c) when naval forces were  
insufficient for long distance patrol and search operations, and Army  
aircraft were made available, these aircraft would be under the tactical  
control of the naval commander directing the search operations.  
 
Paragraph III provided for Joint communications, and, among other  
things, that all information of the presence or movements of hostile  
aircraft offshore from Oahu secured through Navy channels would be  
transmitted promptly to the Command Post of the Army Provisional Anti- 
Aircraft Brigade and the Aircraft Warning Service Information Center;  
that subsequently, when the Army aircraft warning service was  
established, provision would be made for transmission of information on  
the location or distance of hostile and friendly aircraft, and special  
wire or radio circuits would be made available for the use of Navy  
liaison officers so that they might make their own evaluation of the  
available information and transmit it to their respective organizations.  
 
Paragraph IV related to Joint anti-aircraft measures, the arrival and  
departure procedure for aircraft, balloon barrages, Marine Corps anti- 
aircraft artillery, and Army Aircraft Warning Service. It provided that  
the letter service was to be expedited in its installation and operation  
by the Army and, "during the period prior to the completion of the AWS  
installation, the Navy, through use of Radar and other appropriate  
means, will endeavor to give such warning of hostile attacks as may be  
practicable. 
 
[35]

D. Joint Estimate Covering Army and Navy Air Action in the Event  
of Sudden Hostile Action Against Oahu.  
 
On 31 March 1941, Rear Admiral Bellinger, Commander Naval Base Defense  
Air Force (Commander Patrol Wing Two), and Major General F. L. Martin,  
Commanding Hawaiian Air Force, prepared a joint estimate covering joint  
Army and Navy air action in the event of sudden hostile action against  
Oahu or Fleet units in the Hawaiian area (Exhibit 49).  
 
Paragraph I of the estimate included a "Summary of the Situation," which  
indicated that relations between the United States and Orange were  
strained, uncertain, and varying; that in the past Orange had never  
preceded hostile action by a declaration of war; that a suc- 
 
Page 414 
 
cessful sudden raid against our ships and naval installations on Oahu  
might prevent effective offensive action by our forces in the western  
Pacific for a long period; that a strong part of our fleet was  
constantly at sea in the operating areas, organized to take prompt  
offensive action; and, that it appeared possible that Orange submarines  
and/or an Orange fast raiding force might arrive in Hawaiian waters with  
no prior warning from our Intelligence Service.  
 
Paragraph II of the estimate embraced a "Survey of Opposing Strengths,"  
indicating among other things, that Orange might send into the Hawaiian  
area one or more submarines and one or more fast raiding forces composed  
of carriers supported by fast cruisers; that the most difficult  
situation to meet would be when several of the above elements were  
present and closely coordinating their actions; and that the aircraft  
available in Hawaii were inadequate to maintain for any extended period  
from bases on Oahu a patrol extensive enough to insure that an air  
attack from an Orange carrier could not arrive over Oahu as a complete  
surprise.  
 
Paragraph III of the estimate dealt with "Possible Enemy Action." It  
stated that a declaration of war might be preceded by a surprise  
submarine attack on ships in the operating area, a surprise attack on  
Oahu, including ships and installations in Pearl Harbor, or a  
combination of these two; that it appeared the most likely and dangerous  
form of attack on Oahu would be an air attack, most likely launched from  
one or more carriers which would probably approach inside of 300 miles.  
It was further pointed out that a single attack might or might not  
indicate the presence of more submarines or more planes waiting to  
attack after defending aircraft have been drawn away by the original  
thrust; that: "(d) any single submarine attack might indicate the  
presence of considerable undiscovered surface forces, probably composed  
of fast ships accompanied by a carrier;" and that in a dawn air attack  
there was a high possibility that it could be delivered as a complete  
surprise in spite of any patrol that we might be using.  
 
Paragraph IV of the estimate considered "Action Open to Us." It was  
stated that it would be desirable to run daily patrols as far as  
possible to seaward through 360 , but this could only be effectively  
maintained with present personnel and material for a very short period,  
and, as a practicable measure, could not therefore be undertaken unless  
other intelligence [36] indicated that a surface raid was probable  
within rather narrow limits of time. Reference was made to other types  
of action open in the event of a surprise attack on ships in the  
operating area or on the islands, and pointed out that none of the  
outlined courses of action could be initiated by our forces until an  
attack was known to be imminent or had occurred.  
 
Paragraph V contained "Decisions." The primary decision was that the  
Naval Base Defense Air Force would locate and attack forces initiating  
hostile action against Oahu or fleet units in order to prevent or  
minimize damage to our forces from a surprise attack, and to obtain  
information upon which to base coordinated retaliatory measures. A  
number of subsidiary decisions were made, including decisions for the  
establishment of a search and attack group, an air combat group, the  
assignment of missions to the groups, and definitions of conditions of  
readiness. The search and attack group was to be under the Commander  
Naval Base Defense Air Force-Commander 
 
Page 415 
 
Patrol Wing Two, and, in accordance with current conditions of  
readiness, included patrol squadrons and Army bombardment and  
reconnaissance squadrons.  
 
[37]

E. Naval Base Defense Force Operation Plan No. 1-41, and Naval Base  
Defense Air Force Plan.  
 
Admiral Block, as Naval Base Defense Officer, issued his Operation Plan  
No. 141, on February 27,1941 (Exhibit 53 of the Naval Court). The Task  
Organization prescribed was: (a) Destroyer Patrol (Commander Inshore  
Patrol) consisting of two destroyers, a boom patrol, a harbor patrol,  
and A/B boom and minesweepers, (b) Base Defense Air Force (Commander  
Patrol Wing Two) in conjunction with the Army, (c) Antiaircraft Defense  
(District Marine Officer) in conjunction with the Army, (d) Harbor  
Control Post (District Operations Officer) in conjunction with the Army.  
This plan directed attention, among other things to the Hawaiian Joint  
Coastal Frontier Defense Plan, and stated:  
 
"By cooperation in support of the Army, Naval security measures will be  
established as necessary for the joint protection of Pearl Harbor base  
in order to safeguard the Fleet.  
 
"In conjunction with the Commanding General Hawaiian Department the  
Naval base Defense Officer (Commandant Fourteenth Naval District) will  
arrange to coordinate joint effort; to set conditions of readiness; to  
hold required drills; to make "alarm" and "all clear" signals.  
 
"Assumptions.  
 
"(a) That no responsible foreign power will provoke war under existing  
conditions by attack on the Fleet or base but that irresponsible and  
misguided nationals is of such powers may attempt:  
 
"(1) Sabotage from small craft on ships based in PEARL HARBOR.  
 
"(2) Block the entrance channel to PEARL HARBOR by sinking an  
obstruction in the channel.  
 
"(3) Lay magnetic or other mines in the approaches to PEARL HARBOR.  
 
"(b) That a declaration of war might be preceded by:  
 
"(1) A surprise submarine attack on ships in base area-probable.  
 
"(2) A surprise air attack on ships in PEARL HARBOR-possible.  
 
"(3) A combination of these two-possible." 
 
Annexed to Operation Plan 1-41 were: A detailed Inshore Patrol Plan,  
called Annex "A; " a detailed Naval-Base Defense Air Force Plan, called  
Annex "Baker;" a detailed Anti-aircraft Defense Plan, called Annex "C;"  
a detailed Harbor Control Post Plan, called "D;" and a detailed  
Communications Plan, known as Annex "Easy."  
 
Annex "Baker," the detailed Naval Base Defense Air Force Plan, dated 9  
April 1941, was prepared by Admiral Bellinger and approved by Admiral  
Block. It divided the Task Organization into (a) Search and Attack  
Group, consisting of patrol squadrons and other planes, including Army  
reconnaissance squadrons, and (b) an air combat group. This plan was  
made in accordance with the Joint Estimate, dated 31 March 1941 which is  
digested above. The Naval Base Defense Air Force was, according to this  
plan, to [38] locate and destroy hostile forces raiding against Oahu or  
Fleet units in the operating areas. The plan was effective upon receipt  
and became operative without signal in the event of a surprise attack on  
Oahu. It might be made operative by dispatch. In the meantime,  
conditions of readiness, described in Addendum Two to this plan, would  
be taken as directed by the Commanding General, Hawaiian Department, for  
Army units, and by the Naval Base Defense Officer (ComFOURTEEN) for Navy  
 
Page 416 
 
units. The condition of material readiness was to be signified by a  
letter, such as "E," signifying that all aircraft were conducting  
routine operations and none were ready for the purpose of this plan, and  
the condition of operational readiness by a number, such as "5,"  
signifying that all types of available planes would be ready in four  
hours. It was also required that a dispatch readiness report, as of 1500  
each day, be made by each unit assigned by this plan to a task group,  
stating the number of planes and readiness.  
 
[39]

F. Pacific Fleet letter on Security of the Fleet at Base and in  
Operating Areas.  
 
Pacific Fleet Confidential Letter No. 2CL-41, from the Commander in  
Chief, Pacific Fleet, to the Pacific Fleet, concerning the security of  
the Fleet at base and in operating areas, was issued in February, 1911  
and reissued in revised form on 14 October 1941.  
 
This order provided that the Security of the Fleet was predicated on two  
assumptions:  
 
(a) That no responsible foreign power would provoke war under present  
existing conditions by attack on the Fleet or base, but that  
irresponsible and misguided nationals of such powers might attempt  
 
(1) sabotage on ships based in Pearl Harbor from small craft,  
 
(2) to block the entrance to Pearl Harbor by sinking an obstruction in  
the channel,  
 
(3) to lay magnetic or other mines in the approaches to Pearl Harbor;  
 
(b) That a declaration of war might be preceded by (1) a surprise attack  
on ships in Pearl Harbor, (2) a surprise submarine attack on ships in  
operating areas, (3) a combination of the two.  
 
Security measures were prescribed covering:  
 
A. Continuous patrols, inshore, boom and harbor.  
 
B. Intermittent patrols to consist of a destroyer offshore patrol and  
all air patrol. The destroyer patrol was to consist (a) of a patrol to  
10 miles from the entrance, (b) three destroyers to search 12 hours  
prior to sortie or entry of Fleet or Task Force, (c) one destroyer  
(READY DUTY) for screening heavy ships, other than during a Fleet or  
Task Force sortie or entry, to be on one hour's notice. The air patrol  
was to consist of daily search of operating areas, as directed by  
Commander Aircraft, Scouting Force, an air patrol to cover entry or  
sortie of a Fleet or Task Force, an air patrol during entry or departure  
of a heavy ship at other times. There also was to be a daily sweep for  
magnetic and anchored mines.  
 
C. Sortie and entry.  
 
D. Operating areas.  
 
E. Ships at sea.  
 
F. Ships in port.  
 
The security provisions covering defense against air attack (G),  
described the principal Army anti-aircraft gun defenses of Pearl Harbor  
and directed that Marine defense battalions would assist the Army in  
manning them; and provided that in the event of a hostile air attack,  
any part of the Fleet in harbor, plus all fleet aviation shore based on  
Oahu, would augment the local air defense; it prescribed air defense  
sectors and a berthing plan in Pearl Harbor. It further provided that  
the senior officer embarked, exclusively of CincPac, should insure  
berthing so as to develop the maximum anti-aircraft gunfire; 
 
Page 417 
 
and that ComFOURTEEN, as Naval [40] Base Defense Officer, should  
exercise with the Army joint supervisory control over the defense  
against air attack, and take other action, including supervisory control  
over naval shore based aircraft, arranging through the Commander of  
Patrol Wing Two for coordination of the joint air effort between the  
Army and the Navy, and coordinate Fleet antiaircraft fire with the base  
defense by advising the Senior Officer Embarked (exclusive of CincPac)  
of the condition of readiness to maintain, and by holding drills, etc.  
 
Three conditions of naval base defense readiness were prescribed.  
Condition III read as follows:  
 
"Anti-aircraft battery (guns which bear in assigned sector) of at least  
one ship in each sector manned and ready. (Minimum of four guns required  
for each sector.) Condition of aircraft as prescribed by Naval base  
Defense Officer." 
 
The procedure to be followed by the task forces in the event of an air  
attack was also se forth: the Senior Officer embarked was to execute an  
emergency sortie order, sending destroyers out and preparing a carrier  
and heavy ships and submarines for sorties; the Task Force Commander at  
sea was to dispatch a striking unit, etc.; and the Naval Base Defense  
Officer was to give the alarm indicating that an attack was in progress  
or imminent, inform the Task Force Commander at sea of the attack and  
type of attacking aircraft, launch air search for enemy ships, and arm  
and prepare all bombing units available.  
 
The action to be taken if a submarine attacked in the operating area was  
set forth. It was provided that the ship attacked was, among other  
things, to originate a plain language dispatch containing the essential  
details; various actions were to be taken by other ships; and the Patrol  
Wings were to assume readiness for search and for offensive action, to  
carry out search as directed by Task Force Commander, and to prepare to  
establish station patrol at a 220 mile radius from the scene of attack  
at one hour before daylight of the next succeeding daylight period. The  
shore based fleet aircraft were to prepare to relieve planes over the  
attack area, unless Pearl Harbor were also attacked, in which case the  
instructions issued by the Naval Base Defense Officer would have  
priority. It was further provided that "It must be remembered that a  
single attack may or may not indicate the presence of more submarines  
waiting to attack," and "(3) it must be remembered too, that a single  
submarine attack may indicate the presence of a considerable surface  
force probably composed of fast ships accompanied by a carrier. The Task  
Force Commander must, therefore, assemble his task groups as quickly as  
the situation and daylight conditions warrant in order to be prepared to  
pursue or meet enemy ships that may be located by air search or other  
means."  
 
[41]

G. Execution of Plans Prior to 7 December 1941.  
 
(1) The Pacific Fleet Operating Plan Rainbow 5 provided that the day of  
execution of the plan was to be designated as W-Day, and that the day  
upon which hostilities opened with Japan would be J-Day, which might or  
might not coincide with W-Day. Prior to the attack on Pearl Harbor, W- 
Day had not been designated.  
 
(2) The Joint Coastal Frontier Defense Plan had been signed and placed  
in effect on 11 April 1941 by the Commanding General, Hawaiian  
Department, and by the Commandant, Fourteenth Naval District. It will be  
recalled that under this plan the method of coordination of  
 
Page 418 
 
Army and Navy effort was "by mutual cooperation" and not "unity of  
command." It will be recalled further that under this plan the Army task  
was to hold Oahu against attacks by sea, land, and air forces, and  
against hostile sympathizers; and to support the Naval forces; and, that  
the Navy task was to patrol the coastal zone and control and protect  
shipping therein; and to support the Army forces; and, that the Navy was  
obliged to provide distant reconnaissance.  
 
(3) Annex VII, Section 6 of the Joint Coastal Frontier Defense Plan,  
which provided for joint defensive measures for defense against hostile  
raids or air attacks delivered prior to a declaration of war (including  
joint air operations and for the use of Army aircraft by the Navy for  
long distance patrol when Navy forces were insufficient), was to become  
effective when the Commanding General and ComFOURTEEN agreed that the  
threat of a hostile raid or attack was sufficiently imminent to warrant  
such action. No such agreement was made prior to the attack on December  
7th.  
 
(4) The Naval Base Defense Force Operation Plan, which provided for an  
Inshore Patrol consisting of two destroyers, a boom patrol, a harbor  
patrol, and an A/B boom and minesweepers, a Base defense air force,  
anti-aircraft defense, and a harbor control post, although effective as  
to the inshore patrol was not in operation as to the base defense air  
force.  
 
(5) The Naval Base Defense Air Force Plan, dated 9 April 1941, which was  
an annex to the Naval Base Defense Force Plan and which had been made in  
accordance with the joint estimate of Bellinger and Martin, dated 31  
March 1941, was effective upon receipt. It was to become operative  
without a signal in the event of a surprise attack on Oahu and it might  
have been made operative by dispatch. It was not made operative until  
the attack on 7 December 1941.  
 
(6) The Pacific Fleet Letter on security of the Fleet at base and in  
operating areas, which recognized the possibility of a surprise attack  
on ships in Pearl Harbor and which set forth security measures including  
patrols to be conducted both by destroyers and by aircraft, was in  
effect during 1941, and in revised form after 14 October 1941.  
 
[42]

H. Admiral Kimmel's Views as to the Possibility of a Surprise Air  
Attack.  
 
It appears from the War and Defense Plans, above summarized, that it was  
believed that prior to a declaration of war there might be a surprise  
attack by the Japanese on ships in Pearl Harbor or a surprise submarine  
attack on ships in the operating areas. The possibility of a surprise  
air attack on ships in Pearl Harbor had been expressed as early as 24  
January 1941 by the Secretary of the Navy, in a letter to the Secretary  
of War (Exhibit 64), a copy of which was received by Admiral Kimmel  
shortly after he assumed command of the Pacific Fleet. In that letter,  
the Secretary of the Navy wrote:  
 
"If war eventuates with Japan, it is believed easily possible that  
hostilities would be initiated by a surprise attack upon the fleet or  
the naval base at Pearl Harbor . . . The dangers envisaged in their  
order of importance and probabilities are considered to be (1) air  
bombing attack, (2) air torpedo plane attack, (3) sabotages (4)  
submarine attack (5) mining (6) bombardment by gunfire." 
 
In his testimony before the Naval Court of Inquiry, Admiral Kimmel  
indicated some confusion as to his agreement with and his evalua- 
 
Page 419 
 
tion of the above letter by the Secretary of the Navy. He testified that  
he had felt that the most probable form of attack on Pearl Harbor was by  
submarine, and that a bombing attack was the second most probable, but  
that he had been of the view that there was no danger of an air torpedo  
attack because the water was too shallow. He then corrected his  
testimony, characterizing his previous testimony as erroneous, and  
stated that he had regarded an air attack as no more than a possibility.  
 
It appears clearly that Admiral Kimmel at all times during his command  
of the Pacific Fleet was of the view that a surprise air attack on Pearl  
Harbor was a possibility. Thus, in a letter by Admiral Richardson,  
prepared in collaboration with Admiral Kimmel, on 25 January 1941  
(Exhibit 70, Naval Court), it was stated in part that the security of  
the Pacific Fleet would be predicated on certain assumptions, including  
an assumption that Japan might attack without warning and the further  
assumption that Japanese attacks might be expected against shipping,  
outlying position, or naval units, and that surprise raids on Pearl  
Harbor were possible. Again, in a letter of 18 February 1941, concerning  
the adequacy of local defense (Exhibit 30. Naval Court), Admiral Kimmel  
stated "I feel that a surprise attack (submarine, air, or combined) on  
Pearl Harbor is a possibility." And, as previously pointed out the Fleet  
Security Letter, reissued on 14 October 1941, predicated the security of  
the Fleet on two assumptions. One of which was that a declaration of war  
might be preceded by a surprise attack on ships in Pearl Harbor. This,  
Admiral Kimmel testified before the Naval Court, referred to a surprise  
air attack.  
 
In connection with Admiral Kimmel's statement before the Naval Court of  
Inquiry that he thought there was no danger of an air [43] torpedo  
attack on Pearl Harbor because the water was too hallow, several letters  
from the Chief of Naval Operations should be noted:  
 
On 15 February 1941 (Exhibit 49, Naval Court), the Chief of Naval  
Operations wrote to CincPac regarding anti-torpedo baffles for  
protection against attacks on Pearl Harbor. This stated that the shallow  
depth of water limited the need for anti-torpedo nets in Pearl Harbor  
and the congestion and the necessity for maneuvering room limited he  
practicability of the present type of baffles. The letter indicated hat  
a minimum depth of water of 75 feet might be assumed necessary  
successfully to drop torpedoes from planes and that the desirable height  
for dropping is 60 feet or less. There were various other considerations  
stated. The recommendations and comments of the Commander-in-Chief were  
especially desired. A similar letter was sent by the Chief of Naval  
Operations to the Commandants of various Naval Districts, including the  
Fourteenth, on 17 February 1941 (Exhibit 54, Naval Court).  
 
The reply to the request for recommendations and comments was made on 20  
March 1941, in a letter by Admiral Bloch, stating that the depth of  
water at Pearl Harbor was 45 feet, and for that and other reasons, he  
did not recommend anti-torpedo baffles. CincPac agreed, until such time  
as a light efficient net were [sic] developed.  
 
In June 1941, the Chief of Naval Operations sent another letter to he  
Commandants of Naval Districts, copy to CincPac and others,  
 
Page 420  
 
referring to recent developments, and to experience at Taranto, which  
stated that no minimum depth of water could be assumed safe as regards  
torpedo attack if there were sufficient water around a ship to permit an  
attack to be developed and a sufficient run to arm the torpedo, but that  
such an attack in 10 fathoms or more was more likely than in shallow  
water (Exhibit 55, Naval Court). The torpedoes at Taranto, it was said,  
were launched in thirteen to fifteen fathoms although some may have been  
in eleven.  
 
Admiral Kimmel testified that on this correspondence he based his  
opinion that there was no chance of an air torpedo attack on Pearl  
Harbor-and that even after the June letter, he did not think that  
torpedoes would run in such shallow water. He pointed out that the Navy  
made no effort to place such nets in Pearl Harbor. He later stated that  
he did not think an aerial torpedo attack would be made because he did  
not think such torpedoes would run in Pearl Harbor and did not give this  
a great deal of consideration for that reason.  
 
[44]

I. Adequacy of Forces to Carry Out Tasks Assigned.  
 
The adequacy of forces assigned to the Pacific Fleet for carrying out  
the tasks assigned in the war plans was the subject of testimony before  
both Admiral Hart and the Naval Court of Inquiry. From the testimony it  
appears that although there were shortages concerning which Admiral  
Kimmel had extensive correspondence with the Chief of Naval Operations,  
there was general agreement by the witnesses to the effect that the  
Fleet was considered adequate to carry out the initial tasks assigned in  
the war plans. The initial tasks, it will be recalled, were primarily  
defensive in nature. As will appear subsequently in this report, the  
number of fleet patrol planes in the Hawaiian area was not sufficient to  
enable a 360 degree reconnaissance to be flown daily from Oahu for more  
than a few days, but was sufficient for air reconnaissance of the more  
dangerous sectors to have been flown for at least several weeks. To this  
extent, therefore, the patrol planes assigned to the Pacific Fleet were  
a limiting factor as to the Fleet's ability to carry out one of the  
initial tasks assigned in the war plans, namely, to "maintain air  
patrols against enemy forces in the approaches of Oahu . . ."  
 
The Joint Coastal Frontier Defense Plan stated that the Navy, through  
ComFOURTEEN, would provide for distant reconnaissance from Oahu. Admiral  
Bloch had no air forces assigned to him and had to rely upon the Fleet  
planes, which were under the control of Admiral Kimmel, for the  
accomplishment of this task. Thus naval patrol planes could be and were  
used for long distance reconnaissance from Oahu only when they were made  
available by Admiral Kimmel for that purpose.  
 
[45]

J. Command Organization. 
 
(1) Methods of Coordination Between Army and Navy Commands. According to  
"Joint Action of the Army and Navy, 1935," (Exhibit 6, Naval Court), the  
operations of Army and Navy forces were to be coordinated by one of two  
methods:  
 
(a) Mutual cooperation, or,  
(b) The exercise of unity of command  
 
(2) Coordination Between Army and Navy Commands in Hawaii. The command  
organization in the Hawaiian area was designed to function through  
"mutual cooperation" between the Army and Navy. 
 
Page 421 
 
This was the normal method of coordination according to Joint Action of  
the Army and the Navy (Exhibit 6, page 5), and applied to the defense of  
Pearl Harbor as well as the entire Hawaiian area.  
 
(3) Desirability of Unity of Command.-(a) Unity of Command for Hawaii  
considered in Washington. Admiral Stark testified before the Naval Court  
that, prior to 7 December 1941, he had given much thought to the  
question of unity of command in Hawaii but that no satisfactory solution  
or decision had been reached as far as the Navy Department was  
concerned. It had been the topic of many conversations with the Chief of  
Staff of the Army, but it was anticipated only for amphibious operation  
(page 29, Naval Court). He and the Chief of Staff of the Army could have  
placed unity of command into effect at Hawaii, subject to the approval  
of the Secretaries of War and of the Navy (page 39. Naval Court).  
However, "Joint Action of the Army and Navy" (Exhibit 6, Naval (Court)  
does not indicate that the approval of the Secretary of War and the  
Secretary of the Navy would have been required.  
 
(b) Unity of Command for Hawaii considered at Pearl Harbor. Admiral  
Stark testified that Admiral Kimmel, as Commander-in-Chief of the  
Pacific Fleet in mutual agreement with the Commanding General Hawaiian  
Department could have placed unity of command in effect in Oahu (Naval  
Court page 39; Exhibit 6, page 5). Admiral Kimmel testified (Roberts  
Commission page 538; Naval Court, page 296) that he had never had any  
discussion with the Commanding General of the Hawaiian Department on the  
desirability of putting unity of command into effect in the Hawaiian  
area, but did state that where command is vested in one agency, much  
better results can be obtained than when responsibility is divided.  
 
Admiral Kimmel testified that so far as the authority of ComFOURTEEN to  
accomplish unity of command was concerned, ComFOURTEEN did not have the  
authority without reference to him and that he would not have approved  
this nor accepted the responsibility for Army action without reference  
to the Navy Department.  
 
[46] Under the Naval Base Defense Plan (Exhibit 53, NC), unity of  
command was vested in the Commander Naval Base Defense Air Force over  
all offensive air operations and under the Army Air Commander for all  
defensive air operations, but only after the plan had been activated.  
 
(c) Weakness of a  "Mutual Cooperation."  
 
(i) Air Command.-Admiral Bellinger testified that the weakness of the  
air defense plan was that there was no one officer in command until  
after the plan was activated. The Bellinger-Martin estimate (Exhibit 49)  
he believed to be sound, but said that it lacked sanction and that the  
missing sanction was unity of command.  
 
(ii) Recommendation of Joint Command Center.-In an endorsement dated 6  
December 1941 from the Director, Radio Liaison Division, to the Director  
Naval Districts Division, advocating a combined operating center for the  
Army and Navy at Pearl Harbor (which was not established prior to the  
attack). Admiral Hooper stated "The most perfect set-up for command is  
one in which the supreme commander [sic] is exercised by one officer  
best equipped of any for the task . . . Because our defense is under two  
officers, Army and Navy, we must try and arrange matters so that when  
component parts of the  
 
Page 422 
 
commands are interwoven these two can function as nearly as possible as  
one." (Exhibit 77).  
 
The recommendation for a Joint Command Center in Hawaii was originated  
by a dispatch from OpNav to ComFOURTEEN on 15 October 1941 (Exhibit 77),  
requesting that consideration be given to the construction of a combined  
operating center sufficient in size and facilities to accommodate in  
time of emergency staffs of all essential operating activities of both  
Army and Navy in Hawaii. An informal joint working committee had been  
formed in Washington to endeavor to improve cooperation of Army and Navy  
shore defense activities by the formation of joint command centers. A  
reply to the above-mentioned dispatch strongly recommending against such  
a move is contained in a letter from ComFOURTEEN to CNO, via CincPac,  
enclosing a letter from General Short to ComFOURTEEN and an endorsement  
by CincPac. 
 
General Short stated that while he was strongly in favor of combined  
operating centers for equivalent units of Army and Navy forces, he did  
not believe that all of the operating centers should be combined into  
one single building, because it was necessary that Army headquarters be  
located in separate command posts for efficiency of individual  
operation. It was also undesirable from the communication and security  
standpoint. He suggested that, as an alternative, additional space for  
Navy units be constructed adjacent to the existing command posts for  
equivalent Army units.  
 
[47] In the basic letter (Exhibit 77) ComFOURTEEN recommended that no  
steps be taken to concentrate the Army and Navy in a common building and  
believed that the best interests of the CinC Pacific Fleet would be  
served by one building with only agencies of the Fleet therein.  
 
The CinCPacific Fleet in his endorsement to this letter stated that the  
mission of the Army and the Fleet were considerably different, the  
operation of one being defensive and local, while the operations of the  
other were offensive and far-flung. Strategic, rather than tactical,  
cooperation was indicated and therefore the necessity for rapid receipt  
and exchange of information and arrival at quick decision was of less  
importance. He was of the opinion that the establishment of a combined  
operating center for the Army and Navy in Hawaii was not only  
unnecessary, but definitely undesirable.  
 
(4) Disagreement concerning Unity of Command at the Outlying Islands.- 
The evidence in the previous investigations and in this investigation  
indicates that there was some consideration of unity of command at  
outlying islands during the critical period 27 November to 7 December  
1941. This occurred as a result of dispatches by the Chief of Naval  
Operations to CincPac on 26 November 1941 (Exhibits 18 and 40, Naval  
Court), in which it was advised that the Army had agreed to reinforce  
Midway and Wake with Army personnel and to station 25 Army pursuit  
planes at Midway and 25 at Wake provided that Admiral Kimmel considered  
this feasible and desirable. It was stated that it would be necessary  
for Admiral Kimmel to transport these planes and ground crews from Oahu  
to Midway and Wake on aircraft carriers, that the planes would be flown  
off at destination and that the ground crews would be landed in boats.  
Admiral Kimmel was directed to confer with the Commanding General  
concerning this matter, and to advise as soon as practicable. 
 
Page 423 
 
It appears that this subject was considered at some length in  
conferences held by Admiral Kimmel on and after 27 November 1941. The  
discussion of unity of command as to these islands was summarized by  
Vice Admiral Smith in his testimony in this investigation. He said that  
Admiral Kimmel asked the Army what he could expect of Army fighters at  
Wake, and that General Martin of the Army Air Force replied that the  
Army did not allow such planes to go more than 15 miles offshore.  
Admiral Kimmel then stated that the Army planes were, therefore, no good  
to him.  
 
General Short stated that if he manned those islands, he must command  
them and "Kimmel replied, 'Over my dead body. The Army should exercise  
no command over Navy bases.' General Short replied, 'Mind you, I don't  
want these islands. I think they are better manned by Marines. But if I  
must put planes and troops on them, then I must command them.' " (Page  
352, record of this investigation).  
 
[48] Admiral Kimmel's concern over the question of command at the  
outlying islands was indicated by his dispatch of November 28th to the  
Chief of Naval Operations, advising of the proposed reinforcement of  
Midway and Wake with Marine fighter planes and that he would investigate  
more thoroughly the feasibility and practicability of relieving them  
with Army planes. In this dispatch he stated, "All outlying forces must  
be exclusively under Naval command" (Exhibit 76, Naval Court).  
Similarly, in a letter of 2 December l941 to Admiral Stark (Exhibit 50  
of the Naval Court), Admiral Kimmel advised that the dispatches in  
regard to the use of Army personnel were being given earnest  
consideration, that he believed Admiral Stark would subscribe to the  
principle that all these outlying islands must be under Navy command and  
the forces there subject to the orders of the Commander-in-Chief without  
any qualifications whatsoever, and that he expected some difficulties  
along this line when Army personnel were injected into the picture  
unless a very clear directive were issued jointly by the War and Navy  
Departments.  
 
It appears that Midway and Wake were reinforced with squadrons of Marine  
planes, and that therefore, unity of command under the Navy, actually  
existed at those islands. No solution of the command problem, in the  
event of possible future inclusion of Army forces, was reached.  
 
[49]

FINDINGS 
 
l. The basic assumption of the Rainbow Five War Plan was that the United  
States and her Allies would be at war with the Axis Powers, either  
including or excluding Japan.  
 
2. The Navy Basic War Plan (Rainbow Five) assigned various offensive  
tasks to the Pacific Fleet, including the capture of positions in the  
Marshalls and raids on enemy sea communications and positions, and  
various defensive tasks, including the task of protecting the territory  
of the Associated Powers in the Pacific area and preventing the  
extension of enemy military power into the Eastern Hemisphere by  
destroying hostile expeditions.  
 
3. The Pacific Fleet Operating Plan (Rainbow Five) assigned to the Fleet  
various initial tasks, including the maintenance of fleet security at  
the bases, at anchorages, and at sea, the protection of the  
communications and territory of the Associated Powers by patrolling with  
light forces and patrol planes, the establishment of defensive submarine  
 
Page 424 
 
patrols at Wake and Midway, and guarding against surprise attack by  
Japan.  
 
4. The Pacific Fleet Operating Plan (Rainbow Five) and annexes included  
among the initial tasks to be performed by the patrol planes the  
maintenance of the maximum patrol plane search practicable in the  
approaches to the Hawaiian area.  
 
5. The Pacific Fleet Operating Plan was to be put into effect on W-day,  
which, it was stated, might or might not coincide with the day that  
hostilities opened with Japan. W-day was not fixed prior to the attack.  
 
6. The Joint Coastal Frontier Defense Plan, Hawaiian Theater, was based  
on the Joint Army and Navy Basic War Plans. It constituted the basis of  
subsidiary peace and war projects, joint operating plans, and  
mobilization plans. The method of coordination under the plan was to be  
by mutual cooperation until and unless unity of command were invoked. 
 
7. Under the Joint Coastal Frontier Defense Plan the Army's task was to  
hold Oahu against attacks by sea, land and air forces, and against  
hostile sympathizers, and to support the naval forces. The Navy's task  
was to patrol the coastal zone (which included Oahu and such adjacent  
land and sea areas as were required for the defense of Oahu), and to  
patrol and protect shipping therein, and to support the Army forces.  
 
8. One of the specific tasks assigned to the Navy in the Joint Coastal  
Frontier Defense Plan was that the Commandant, FOURTEENTH Naval  
District, should provide for distant reconnaissance.  
 
[50] 9. The Joint Coastal Frontier Defense Plan was placed in effect on  
11 April 1941 by the Commanding General, Hawaiian Department, and by the  
Commandant, FOURTEENTH Naval District.  
 
10. Annex VII, Section VI, to the Joint Coastal Frontier Defense Plan  
was an agreement between the Commandant, FOURTEENTH Naval District, and  
the Commanding General Hawaiian Department, as to joint defensive  
measures for the security of the Fleet and for the Pearl Harbor Naval  
Base against hostile raids or air attacks delivered prior to a  
declaration of war.  
 
11. Annex VII, Section VI, to the Joint Coastal Frontier Defense Plan  
provided among other things, for joint air operations and provided that  
when naval forces were insufficient for long distance patrol and search  
operations and Army aircraft were made available, the latter would be  
under the tactical control of the naval commander directing search  
operations.  
 
12. Annex VII Section VI, to the Joint Coastal Frontier Defense Plan,  
also provided that the Army was to expedite the installation of its  
aircraft warning service, and that prior to the completion of that  
service, the Navy, through the use of radar and other appropriate means,  
would endeavor to give such warning of hostile attacks as might be  
practicable.  
 
13. Annex VII, Section VI of the Joint Coastal Frontier Defense Plan  
provided that when the Commanding General and ComFOURTEEN agreed that  
the threat of a hostile raid or attack was sufficiently imminent to  
warrant such action. Each commander would take steps to make available  
to the other the air forces at his disposal, in order that joint  
operations might be conducted in accordance with the plan. 
 
Page 425 
 
14. The Commanding General and ComFOURTEEN did not effect any agreement  
prior to the attack that the threat of a hostile raid or attack was  
sufficiently imminent to warrant placing Annex VII, Section VI, in  
operation.  
 
15. The Naval Base Defense Force Operation Plan provided, among other  
things, for a Base Defense Air Force in conjunction with the Army. One  
of the assumptions was that it was possible that a declaration of war  
might be preceded by a surprise air attack on ships in Pearl Harbor,  
that it was probable that there might be a surprise submarine attack on  
ships in the base area, and that a combination of both forms of attack  
was possible.  
 
16. The joint estimate by Admiral Bellinger and General Martin stated,  
among other things, that the most likely and dangerous form of attack on  
Oahu would be an air attack that would most likely be launched from  
carriers which would probably approach inside of three hundred miles.  
The estimate also stated that any single submarine attack might indicate  
the presence of considerable undiscovered surface forces, probably  
composed of [51] fast ships accompanied by a carrier. This Estimate came  
to the attention of Admiral Kimmel and Admiral Bloch.  
 
17. The Naval Base Defense Air Force Plan was prepared by Admiral  
Bellinger and approved by Admiral Bloch. This plan, which was designated  
Annex "Baker" to the Naval Base Defense Force Operation Plan, made  
specific provision for joint air operations by the Army and Navy. The  
Plan was effective upon receipt. It was to become operative without  
signal in the event of a surprise attack, or might be made operative by  
dispatch. In the meantime conditions of readiness of aircraft were to be  
as directed by the Commanding General, Hawaiian Department, for Army  
units, and by ComFOURTEEN, as Naval Base Defense Officer, for Navy  
units.  
 
18. The Pacific Fleet letter on security of the Fleet at base and in  
operating areas, which was reissued by Admiral Kimmel in revised form on  
14 October 1941, provided that the Fleet's security was predicated on  
several assumptions, one of which was that a declaration of war might be  
preceded by a surprise attack on ships in Pearl Harbor, a surprise  
submarine attack on ships in the operating areas, or a combination of  
the two. This letter also stated that a single submarine attack might  
indicate the presence of a considerable surface force probably composed  
of fast ships accompanied by a carrier.  
 
19. The Pacific Fleet security letter prescribed security measures,  
including provisions for defense against air attack. It provided, among  
other things, that ComFOURTEEN, as Naval Base Defense Officer, should  
exercise with the Army joint supervisory control over the defense  
against air attack and that he should take other action, including  
supervisory control over naval shore-based aircraft, and arrange through  
the Commander of Patrol Wing Two for coordination of the joint air  
effort by the Army and the Navy.  
 
20. Under the Pacific Fleet security letter, the security measures were  
to include intermittent patrols to consist of a destroyer offshore  
patrol, and an air patrol. The air patrol was to consist of daily search  
of fleet operating areas as directed by Aircraft Scouting Force, one  
covering the entry or sortie of a fleet or task force, and one during  
the entry or departure of a heavy ship at other times.  
 
Page 426 
 
21. The only local defense plans in effect and operative prior to the  
attack of 7 December 1941 were the Joint Coastal Frontier Defense Plan,  
under which the Navy was obliged to provide distant reconnaissance, and  
the Pacific Fleet security letter, under which the only aircraft patrol  
from Oahu was a daily search of fleet operating areas, a search during  
entry or sortie of a fleet or task force, and during the entry or  
departure of a heavy ship at other times.  
 
[52] 22. The Pacific Fleet Operating Plan (Rainbow Five), approved by  
the Chief of Naval Operations, in estimating probable enemy (Japanese)  
action, visualized that one of the enemy defensive efforts would be  
"destruction of *threatening* naval forces"; that initial action would  
include "possible raids or stronger attacks on Wake, Midway, and *other  
outlying* United States *positions*"; and that the initial Japanese  
deployment would include "raiding and observation forces *widely  
distributed in the Pacific*, and that *submarines* in the *Hawaiian  
area* ...." (Italics supplied.) The possibility of an attack on Hawaii  
was, therefore, included but in no way emphasized.  
 
23. Admiral Kimmel was of the opinions throughout his tenure of command  
of the Pacific Fleet, that a surprise air attack on Pearl Harbor was a  
possibility. Neither he nor the key members of his staff appear to have  
considered it as a serious *probability*.  
 
24. The method of command established in the local plans was that of  
"mutual cooperation." The relations between the responsible commanders  
were cordial. However, there was not in existence, prior to the attack,  
any permanent operating setup which could ensure the constant and timely  
exchange of information, decisions, and intended courses of action so  
essential to the efficient conduct of joint operations, particularly in  
an emergency. A recent proposal looking to the establishment of a Joint  
Command Center had been the subject of adverse recommendations by the  
responsible local commanders, both Army and Navy.  
 
25. In accordance with "Joint Action," unity of command for the defense  
of Oahu could have been placed in effect by local agreement between the  
Commanding General of the Hawaiian Department and the Commandant of the  
FOURTEENTH Naval District. The latter, however, would naturally not make  
such an agreement without the approval of his immediate superior, the  
Commander-in-Chief, Pacific Fleet. The question of unity of command for  
outlying islands was discussed between Admiral Kimmel and General Short  
in connection with a proposal for reinforcement Of Wake and Midway by  
Army planes General Short's position was that if Army forces were  
involved, the command must be his. Admiral Kimmel maintained that the  
command of Naval bases must remain with the Navy. The islands were  
reinforced with Marine planes.  
 



Page maintained by Larry W. Jewell, lwjewell@omni.cc.purdue.edu. Created: 12/12/96 Updated: 12/12/96