ENDORSEMENTS BY JAG, COMINCH AND SECNAV TO ADMIRAL HEWITT'S REPORT
UNITED STATES FLEET
HEADQUARTERS OF THE COMMANDER IN CHIEF
Washington 25, D. C., 13 Aug. 1945.
Third endorsement to Adm. Hewitt's Report to SecNav dated 12 July 1945.
From: Commander in Chief, United States Fleet and Chief of Naval
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
(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
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.
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
E. J. KING.
Originated by F-00 (Adm. Edwards) 8/10/45.
Rewritten by F-0 (Adm. King) 8/13/45.
10 AUGUST 1945.
From: The Judge Advocate General.
To: Commander-in-Chief, United States Fleet and Chief of Naval
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
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
(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-
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.
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
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.
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.
(a) Report of Commission appointed by the President to investigate and
report the facts relating to the Japanese attack on Pearl Harbor, 7
(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
(e) Record of proceedings and: report of Naval Pearl Harbor Court of
(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).
(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
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.
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.
REPORT BY ADMIRAL H. K. HEWITT ON FURTHER PEARL HARBOR INVESTIGATION
TABLE OF CONTENTS
Introduction. Prior Investigations and Scope of this Investigation
[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
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
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
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
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."
"Execute an appropriate defensive deployment preparatory to carrying out
the tasks assigned."
 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
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.
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
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.
 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
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
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.
 Failure of the War Department to reply to the message relating to
the anti-sabotage measures instituted by the Commanding General,
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
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
the Japanese attack. Admiral Hart completed his examination on 15 June
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.
 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
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
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
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
 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.
 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
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
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
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
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  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
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.
 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
(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
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
(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  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
(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.
 (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
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.
" 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
"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
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.
" 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
"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
"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  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."
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.
F. Witnesses in this Investigation.
At Pearl Harbor in 1941:
Captain Edwin T. Layton, USN, Intelligence Officer, Pacific Fleet. (R.
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.
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)
Commander Wesley A. Wright, USN, Assistant Communications Officer,
CincPac, on temporary duty with Com 14 Communications Intelligence Unit.
Lieutenant (jg) Farnsley C. Woodward, USN, Cryptanalyst, Communications
Intelligence Unit, 14th N. D. (R. 541)
 Colonel Alva B. Yaswell, USMC, Translator, Communications
Intelligence Unit, 14th N. D. (R. 541)
Captain William W. Outerbridge, USN, Commanding Officer, USS WARD. (R.
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.
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.
Mrs. Dorothy Edgers. Research Analyst, ONI. (R. 511)
 Lieutenant Commander Francis M. Brotherhood, USNR. Communications
Security Section. (R. 143)
Lieutenant Frederick L. Freeman, USN, Communications Security Section.
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)
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)
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;
G. Exhibits Received in this Investigation.
Received in this investigation were the following exhibits:
Num- Description Record
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
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
(returned to Captain Layton) .................................. 281
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
Num- Description Record
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
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
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
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]
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....
 CHAPTER III. INFORMATION
1314. The concept of the war in the Pacific, as set forth in ABC-1 is as
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
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
 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
e. Reinforcement of the Mandate Islands by troops, aircraft and light
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
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
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
f. Raiding and observation forces widely distributed in the Pacific, and
submarines in the Hawaiian area.
 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
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:
 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-
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
j. PROSECUTE THE ESTABLISHMENT AND DEFENSE OF SUBSIDIARY BASES AT
MIDWAY, JOHNSTON, PALMYRA, SAMOA, GUAM AND WAKE AND AT CANTON IF
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.
 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
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
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
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.
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
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.
 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
3143. PERFORM TASKS ASSIGNED IN THE PATROL AND SWEEPING PLAN (ANNEX
"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
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.....
United States Pacific Fleet
U. S. S. PENNSYLVANIA, Flagship
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.
 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
(b) Escorting as conditions require and forces available permit.
(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.
(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
(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.
 (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-
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:
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
17. ARMY . The Commanding General, HAWAIIAN DEPARTMENT, shall provide
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.
 b. An antiaircraft and gas defense intelligence and warning
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.
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
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.
 o. Hospitalization of all Army and civil population in the HAWAIIAN
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
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
o. Supply and hospitalization of all local naval defense forces.
 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
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
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-
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
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  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
Patrol Wing Two, and, in accordance with current conditions of
readiness, included patrol squadrons and Army bombardment and
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.
"(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  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
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.
F. Pacific Fleet letter on Security of the Fleet at Base and in
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
(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
(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;
and that ComFOURTEEN, as Naval  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
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
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
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
(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
(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.
H. Admiral Kimmel's Views as to the Possibility of a Surprise Air
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-
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
In connection with Admiral Kimmel's statement before the Naval Court of
Inquiry that he thought there was no danger of an air  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,
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
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.
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.
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
(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.
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.
 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
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
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.
 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.
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
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).
 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
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.
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
patrols at Wake and Midway, and guarding against surprise attack by
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.
 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
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
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.
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
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
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  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
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.
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.
 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, firstname.lastname@example.org. Created: 12/12/96 Updated: 12/12/96