INVESTIGATION OF THE PEARL HARBOR ATTACK -- REPORT OF THE JOINT COMMITTEE ON THE INVESTIGATION OF THE PEARL HARBOR ATTACK

And again: "The absence of positive information as to the location of
the Japanese carriers, a study of the movement which was possible to
them, under radio silence, through the unguarded areas of the Pacific,
and a due appreciation of the possible effects of an air attack should
have induced Admiral Kimmel to take all practicable precautions to
reduce the effectiveness of such an attack." Id.

[273a] In this regard, Admiral Kimmel stated, among other things: "The
failure to identify Japanese carrier traffic, on and after December
first when the call signs changed, was not an unusual condition. During
the six months preceding Pearl Harbor, there were seven periods of eight
to fourteen days each, in which there was a similar uncertainty about
the location of the Japanese battleships. During the six months
preceding Pearl Harbor, there was an almost continual absence of
positive indications of the locations of the cruisers of the Japanese
First Fleet, and eight periods of ten to twenty days each, in which the
location of the greater number of cruisers of the Japanese Second Fleet
was uncertain. As to the Japanese carriers, during the six months
preceding Pearl Harbor, there existed a total of one hundred and thirty-
four days in twelve separate periods each ranging from nine to twenty-
two days, when the location of the Japanese carriers from radio traffic
analysis was uncertain." Committee record, pp. 6727, 6728.

PEARL HARBOR ATTACK             137

THE "MORI CALL"

The Federal Bureau of Investigation on December 6 delivered to
responsible Army and Navy intelligence officers at Hawaii a transcript
of an intercepted trans-Pacific radiotelephone conversation [274]
between a person in Honolulu named "Mori" [275] and an individual in
Japan. The transcript of this conversation indicated, among other
things, that the individual in Japan was interested in the daily flights
of airplanes, particularly large planes, from Honolulu; whether
searchlights were being used; and the number of ships present at Pearl
Harbor. Reference was made during the conversation to various flowers,
[276] the significance of which was not known, but which conceivably
could have been an open code employed to convey information concerning
the presence or absence of fleet vessels to the approaching Japanese
attack force, which could have listened in on the conversation.

Instead of taking action on the basis of the conversation, the office of
the District Intelligence Officer of the Navy decided that it should be
studied further by a Japanese linguist. This was not done until after
the attack and in consequence the transcript of the conversation was not
seen by Admiral Kimmel before December 7. The transcript was delivered
to General Short and his G-2 on the evening of December 6 by Colonel
Bicknell, his assistant G-2, the latter attaching great significance to
the matters discussed. Colonel Bicknell stated that the special agent in
charge of the FBI was alarmed at what he considered the military
implications of the Mori conversation with respect to Pearl Harbor and
that he, Bicknell, concurred in this view, considering the conversation
as very irregular and highly suspicious. He stated, however, that "both
Colonel Fielder and General Short indicated that I was perhaps too
'intelligence conscious' and that to them the message seemed to be quite
in order, and that it was nothing to be excited about." [277] No action
whatever was taken by General Short.

Regardless of what use the Japanese made of the "Mori call," the
conversation should have been, on its very face, of the greatest
significance to the responsible commanders in Hawaii. Members of the
Mori family were the subject of investigation by the FBI, a fact known
to the intelligence offices of both the Army and Navy. An interest by
Japan in the daily flights of "large airplanes" and whether searchlights
were employed could have but one meaning to alert Commanders who were
properly vigilant and should have been prepared for the worst in the
knowledge that hostilities were imminent a desire to know whether air
reconnaissance was being conducted and whether searchlights were
employed for defense against air attack. The undecipherable and
suspicious reference to flowers should have intensified alertness by
reason of the very fact that the true meaning could not be gathered.
*The Mori call pointed directly at Hawaii*.

The decision of the District intelligence Office of the Navy to place
the matter aside for further study was inexcusable and reflects the
apathetic state of alertness throughout the Navy command.

[274] See committee exhibit No. 84 for complete transcript of the
conversation.
[275] The Mori family included Dr. Motokazu Mori, his wife Mrs. Ishiko
Mori, his father Dr. Iga Mori, and his son Victor Motojiro Mori. The
family was the subject of security investigations in Hawaii.
[276] In the course of the conversation the question was asked, "What
kind of dowers are in bloom in Hawaii at present?" The reply was:
"Presently, the flowers in bloom are fewest out of the whole year.
However the hibiscus and the poinsettia are in bloom now."
[277] See affidavit of Col. George W. Bicknell dated February 25, 1945,
before Major Clausen. Committee exhibit No. 148.

138             PEARL HARBOR ATTACK

DETECTION OF JAPANESE SUBMARINE ON MORNING OF DECEMBER

The U. S. S. Condor, a minesweeper, at 3:42 a. m. (Honolulu time)
December 7, reported sighting a submarine periscope off the entrance
buoys to Pearl Harbor in a defensive area where American submarines had
been restricted from operating while submerged. The Condor by visual
signal reported this sighting to the U. S. S. Ward, a destroyer of the
Inshore Patrol between 3:50 and 3:58 a. m. After receiving this
information the Ward searched for the submarine for approximately one
and one-half hours without results. It thereupon contacted the Condor,
inquiring as to the distance and course of the submarine that was
sighted. At 5:20 a. m. the Condor replied but the Ward was unable to
effect the submarine's location on the basis of this information. The
commander of the Ward thought the Condor had been mistaken in concluding
that it had seen a submarine and made no report to higher authority.
[278] The radio conversation between the Ward and the Condor was
overheard and transcribed in the log of the Section Base, Bishop's Point
Oahu, a radio station under the jurisdiction of the Inshore Patrol,
Fourteenth Naval District. Inasmuch as the conversation was solely
between the ships, was not addressed to the Section Base, and no request
was made that it be relayed, the radio station did not report it to
higher authority.

At 6:30 a. m. The U. S. S. Antares, arriving off Pearl Harbor with a
barge in tow, sighted a suspicious object which appeared to be a small
submarine. The Antares notified the Ward, asking it to investigate, and
at approximately 6:33 a. m. observed a Navy patrol plane circle and drop
two "smoke pots" near the object. At 6:40 the Ward sighted an
unidentified submarine apparently following the Antares. The Ward opened
fire at 6:45 and the Antares, observing the fire of the Ward, noted
about the same time that a Navy patrol plane appeared to drop depth
charges or bombs on the submarine. When the submarine keeled over and
started to sink, the Ward ceased firing and then dropped depth charges.

At 6:51 the Ward radioed the Commandant, Fourteenth Naval District: "We
have dropped depth charges upon subs operating in defensive sea area."
The captain of the Ward followed this dispatch with a supplemental
message at 6:53: "We have attacked, fired upon and dropped depth charges
upon submarine operating in defensive sea area." This information was
received by the Chief of Staff to Admiral Bloch at 7:12 and by the Duty
Officer of Admiral Kimmel at 7:15. Admiral Kimmel stated he received
this information between 7:30 and 7:40 a. m.

Admiral Bloch, according to his testimony, was informed by his Chief of
Staff, but in view of numerous previous reports of submarine contacts,
their reaction was that the Ward had probably been mistaken, but that if
it were not a mistake, the Ward and the relief duty destroyer could take
care of the situation; that Admiral Kimmel to whom the information had
been referred had the power to take any action which might be desired.
[279] Admiral Kimmel testified: [280]

"Between 7:30 and 7:40, I received information from the Staff Duty
Officer of the Ward's report, the dispatch of the ready-duty destroyer
to assist the Ward,

[278] See Hewitt inquiry record, pp. 87-92; 428, 429.
[279] Id., at pages 414 416; 452-469. For further details concerning
this incident, see Hewitt inquiry exhibits Nos. 18, 73, 75, and 76.
[280] Committee record, p. 6760-6770.

PEARL HARBOR ATTACK            139

and the efforts then underway to obtain a verification of the Ward's
report. I was awaiting such verification at the time of the attack. In
my judgment, the effort to obtain confirmation of the reported submarine
attack off Pearl Harbor was a proper preliminary to more drastic action
in view of the number of such contacts which had not been been verified
in the past."

It is to be noted, however, that in Admiral Kimmel's own statement he
refers to only two reports concerning possible submarine contacts after
November 3 in addition to the Ward incident. He stated: [281]

"* * * On November 28, 1941, the U. S. S. Helena reported that a radar
operator without knowledge of my orders directing an alert against
submarines was positive that a submarine was in a restricted area. A
search by a task group with three destroyers of the suspected area
produced no contacts. During the night of December 2, 1941, the U. S. S.
Gamble reported a clear metallic echo in latitude 20-30, longitude 158-
23. An investigation directed by Destroyer Division Four produced no
conclusive evidence of the presence of a submarine."

The reported sighting of a submarine periscope at 3:42 a. m. on the
morning of December 7, in close proximity to Pearl Harbor, even though
not verified, should have put the entire Navy command on the qui vive
and when at 6:40 a. m. The presence of a submarine was definitely
established, the entire Navy command should have been on a full alert.
In the Martin-Bellinger estimate annexed to the Joint Coastal Frontier
Defense Plan it was pointed out that a single submarine attack may
indicate the presence of a considerable surface force probably composed
of fast ships accompanied by a carrier. Admiral Kimmel in his letter to
the Fleet, 2CL-41 (Revised), *dated October 14, 1941*, made this
identical statement and followed it with the words: [282] "The Task
Force Commander must, therefore, assemble his task groups as quickly as
the situation and daylight conditions warrant *in order to be prepared
to pursue or meet enemy ships that may be located by air search or other
means*."

The evidence does not reflect that the sighting and sinking of a
submarine, particularly in close proximity to Pearl Harbor, was of such
frequent occurrence as to justify the failure to attach significance to
the events of the morning of December 7. This is especially true when it
is realized that a war warning had been received and Admiral Kimmel's
own estimates indicated the extreme significance of submarine activity.
As a matter of fact the Condor and Ward incidents appear to be the
*first* instance of reported sighting and sinking of a submarine since
the critical turn in our negotiations with Japan.

The reported sighting was at 3:42 a. m., *over 4 hours before the
Japanese air force struck*. Appearing before the Roberts Commission,
General Short commented as follows with respect to the Ward incident:
[283]

"That would under the conditions, have indicated to me that there was
danger. The Navy did not visualize it as anything but a submarine
attack. They considered that and sabotage their greatest danger; and it
was Admiral Bloch's duty as Commander of the District to get that
information to me right away. He stated to me in the presence of
Secretary Knox that at the time he visualized it only as a submarine
attack and was busy with that phase of it and just failed to notify me
that he could see then, after the fact, that he had been absolutely
wrong, but that at the time the urgent necessity of getting the
information to me had not at any rate, I did not get the information
until after the attack."

[281] Id, at p. 6769.
[282] Hewitt inquiry exhibit No. 8; committee exhibit No. 44.
[282] Roberts Commission record, p. 311.

140              PEARL HARBOR ATTACK

The supposed sighting of a submarine at 3:42 a. m. And the attack upon a
submarine at 6:45 a. m., December 7, should have been recognized as
immediate basis for an all-out alert to meet all military contingencies.
[284]

RADAR DETECTION OF JAPANESE RAIDING FORCE

The army radar was scheduled for operation on Sunday morning, December 7
from 4 a. m. to 7 a. m. [284a] The normal operation for training
purposes after 7 a. m. Was discontinued for this particular Sunday by
reason of special authorization obtained from the control officer.

At one of the more remote aircraft warning stations, Opana, Privates
Joseph Lockard and George Elliott had been on duty from 4 to 7 a. m.
Inasmuch as they were waiting for the army truck to return them to
quarters for breakfast, it was decided to operate the radar after 7 a.
m. in order that Private Lockard, who was skilled in the operation of
the radar detector, might afford his partner additional instruction. As
the machine was being adjusted, Private Lockard saw on the radar screen
an unusual formation he had not previously seen in the machine. Inasmuch
as the indicator reflected a large number of planes coming in and he was
confident there was nothing like it in the air, he felt that the machine
must be at fault. After additional checking he found, however, that the
machine was operating properly and concluded at 7:02 a. m. that there
was a large number of planes approaching Oahu at a distance of 132 miles
from 3  east of north. [285]

After some discussion concerning the advisability of informing the
information center, Private Lockard called the center at 7:20 a. m.
advising that a large number of planes were heading toward Oahu from the
direction indicated. It is to be noted that, as General Short stated,
"At 7 a. m. all the men at the information center except the telephone
operator had folded up their equipment and left." [286] The switchboard
operator was unable to do anything about the call and accordingly, since
the information center personnel had departed, referred it to Lt. Kermit
A. Tyler, a pursuit officer of the Air Corps whose tour of duty at the
center was until 8 a. m. He was there solely for training and
observation.

Lieutenant Tyler, upon being advised of the approach of a large number
of planes, told Private Lockard in substance and effect to "forget it."
He assumed that the flight indicated was either a naval patrol, a flight
of Hickam Field bombers, or possibly some B-17's from the mainland that
were scheduled to arrive on December 7.

[284] In the light of the known and declared significance to be attached
to the presence of a Japanese submarine in the vicinity of Pearl Harbor,
this committee does not concur in the implications of the conclusion
made by the Navy Court of Inquiry that: "There was nothing, however, in
the presence of a single sub marine in the vicinity of Oahu to indicate
that an air attack on Pearl Harbor was imminent " See Navy Court of
Inquiry report committee exhibit No. 157.
[284a] In the course of examination by Counsel, General Short was asked
it radar was put on the alert after the warning of November 27. General
Short replied: " That was put into alert during. what I considered the
most dangerous hours of the day for an air attack, from 4 o'clock to 7
o'clock a. m. daily."

Asked if just putting the radar into operation as effective without an
Information Center that worked with it, General Short said: " The
information center was working with it." Committee record page 8054.

The evidence reflects that installation of three permanent radar
stations had not been completed. The mobile sets had been in operation,
however, for some time prior to December 7 with very satisfactory
results See in this regard Note 287, infra.
[285] For complete discussion, see testimony of Joseph L. Lockard, Army
Pearl Harbor Board record, pp. 1014-1034; Navy Court of Inquiry record
p. 628-343; testimony of George E. Elliott, Army Pearl Harbor Board
record, pp. 994-1014; Navy Court of Inquiry record, pages 644-659; and
committee record, p. 13380-13499.
[286] Committee record, p. 7976,

PEARL HARBOR ATTACK              141

General Short stated: [287]

"If he (Tyler) had alerted the interceptor command there would have been
time if the pursuit squadrons had been alerted, to disperse the planes.
There would not have been time to get them in the air. * * *. It would
have made a great difference in the loss * * *. It would have been a
question of split seconds instead of minutes in getting into action."

In testifying before the joint committee, General Short said: [288]

"If Lieutenant Tyler had realized that the incoming flight was Japanese,
there would have been time to disperse the planes but not to warm up the
engines and get them into the air. Lieutenant Tyler made no report of
this matter to me and as far as I know did not report the incident to
the control officer, Major Tyndall after the information center was
manned about 8:30 a. m. This matter was not brought to my attention
until the next day when it was too late to be of value. Had this
incident been reported to the control officer at 8:30 a. m. on the 7th,
he would have informed the Navy and it might have enabled them to locate
the carriers."

If the Army command at Hawaii had been adequately alerted, Lieutenant
Tyler's position would be indefensible. He was at the information center
for training and observation, had no knowledge on which to predicate any
action, and accordingly should have consulted higher authority. His
fatal estimate "Forget it" was empty assumption. The fact that
Lieutenant Tyler took the step that he did, merely tends to demonstrate
how thoroughly unprepared and how completely lacking in readiness the
Army command really was on the morning of December 7.

Further, the evidence reflects that Privates Lockard and Elliott debated
the advisability of informing the Information Center concerning the
approach of a large number of planes. It would appear that this unusual
information concerning a large number of planes so unusual in fact that
Private Lockard stated he had never before seen such a formation should
have provided immediate and compelling reason for advising the
Information Center had the necessary alert been ordered after the
November 27 warning and the proper alertness pervaded the Army command.

While it was not possible with the then state of radar development to
distinguish friendly planes from hostile planes, this fact is of no
application to the situation in Hawaii; for in a command adequately
alerted to war any presumptions of the friendly or enemy character of
approaching forces must be that they are enemy forces. It is to be noted
General Short has stated that if Lieutenant Tyler had alerted the
interceptor command there would have been time to disperse the planes
and to have reduced the losses. The real reason, however, that the
information developed by the radar was of no avail was the failure of
the commanding general to

[287] Roberts Commission record, pp. 312, 313. However, in a memorandum
dated November 14, 1941, Lt. Col. C . A. Powell, Signal Corps, Hawaiian
Department, stated: "In recent exercises held in the Hawaiian 
Department, the operation of the radio set SCR-270 was found to be very
satisfactory. The exercise was started approximately 4:30 in the morning
and with three radio sets in operation. We noted when the planes took
off from the airplane carrier in the oscilloscope. We determined this
distance to be approximately 80 miles, due to the fact the planes would
circle around waiting the assemblage of the remainder from the carrier.

"As soon as the planes were assembled they proceeded toward Hawaii.
*This was very easily determined and within six minutes, the pursuit
aircraft were notified and they took off and intercepted the incoming
bombers at approximately 30 miles from Pearl Harbor* . . ."

A copy of this memorandum was forwarded under date of November 19, 1941,
to Mr. Harvey E. Bundy special assistant to the Secretary of War. See
committee exhibit No. 136.
[288] Committee record, p. 7977.

142              PEARL HARBOR ATTACK

order an alert commensurate with the warning he had been given by the
War Department that hostilities were possible at any moment.

OTHER INTELLIGENCE RECEIVED BY ARMY AND NAVY IN HAWAII

CHANNELS OF INTELLIGENCE

Both the Army and Navy commanders in Hawaii had responsible intelligence
officers whose duty it was to coordinate and evaluate information from
all sources and of all pertinent types for their superiors. The record
reflects full exploitation of all sources for this purpose including the
interview of passengers transiting Hawaii. The record also reflects that
the Federal Bureau of Investigation and other agencies in Hawaii were
supplying Army and Navy intelligence officers with data available. [289]

The Special Agent in Charge of the FBI at Honolulu, for example, stated
that on or about November 28, 1941, he received a radio communication
from Director J. Edgar Hoover to the effect "that peace negotiations
between the United States and Japan were breaking down and to be on the
alert at all times as anything could happen" and that, on the same day,
he delivered this information to responsible Army and Navy intelligence
officers in Hawaii. [290]

THE "MANILA MESSAGE"

Both the Army and Navy intelligence offices received about December 3,
1941, the following dispatch from a British source in Manila through a
British representative in Honolulu: [291]

"We have received considerable intelligence confirming following
developments in Indochina:
  A. 1. Accelerated Japanese preparation of airfields and railways.
     2. Arrival since Nov. 10 of additional 100,000 repeat 100,000
         troops and considerable quantities fighters, medium bombers,
         tanks, and guns (75 mm).
  B. Estimates of specific quantities have already been telegraphed
       Washington Nov 21 by American Military Intelligence here.
  C. *Our considered opinion concludes that Japan envisages early
       hostilities with Britain and U. S. Japan does not repeat not
       intend to attack Russia at present but will act in South*.
  You may inform Chiefs of American Military and Naval Intelligence
       Honolulu."

The assistant G-2 of the Hawaiian Department stated he gave the
foregoing intelligence to General Short. [292]

THE HONOLULU PRESS

The information available in the Hawaiian Islands from the press and the
attendant state of the public mind in the days before Pearl Harbor can
to a great extent be gathered from a recitation of the headlines
appearing in Honolulu newspapers. Among the headlines were the
following: [293]

[288a] Illustrative of the insufficiency of the radar alert is the fact
that although the charts plotting the Japanese force in and plotting the
force as it retired were turned over to higher authority during the
course of the attack, this information was not employed to assist in
locating the Japanese task force and it appears no inquiries were made
concerning it for a considerable period of time after the attack.
[289] See testimony of Col. George W. Bicknell before the joint
committee, committee record, pp. 13536-13620.
[290] See affidavit of Robert L. Shivers, dated April 10, 1945, before
Major Clausen; Clausen investigation, pp. 88-91.
[291] See exhibits, Clausen investigation.
[292] See supplemental affidavit of Col. George W. Bicknell, dated
August 14, 1945, before Clausen.
[293] Committee record, p. 13622-13627.

PEARL HARBOR ATTACK              143

Honolulu Advertiser

November 7, 1941

"Kurusu Carrying Special Note to F. D. R. From Premier Tojo Japan Ready
to Act Unless Tension Eases."
"Japan Waits Before Move in Far East-Aggression in Pacific Appears
Shelved Until Kurusu's Mission has been Completed in U. S."
"Invasion Held too Difficult by Officials Offensive May Start in Middle
East Soon; Invasion of Continent Impracticable at Present."

November 13, 1941

"Tokyo Radio Asserts War is Already on Any Military Moves Only Logical
Result of Encirclement Policy, Japanese Staff Says."
"Envoy Undismayed Carries Broad Powers to Act Kurusu Denies Taking
Message, Implies Errand of Bigger Scope."

November 14, 1941

"Japanese Confident of Naval Victory."

November 26, 1941

"Americans Get Warning to Leave Japan, China."
"Hull Reply to Japan Ready."

November 27, 1941

"U.S.-Japan Talks Broken Off as Hull Rejects Appeasement Full Surrender
Demanded in U. S. Statement."
"Evacuation Speeded as Peace Fades."

November 28, 1941

"Parris Island, S. C. This is the tail assembly of the captive barrage
balloon at Parris Island, S. C., looking for all the world like an air
monster. The wench controlling it is in the sandbagged structure
protected there from bomb splinters. The helium sausage may be used to
protect beachheads, bridgeheads and other strong points thereby
differing from the British technique which keeps them flying over
London. The marines encamped on Parris Island, S. C., have a special
training school on these balloons."

November 29, 1941

"U. S. Rejects Compromise in Far East-Washington Insists on Maintenance
of Status Quo, Withdrawal from China by Japan Army."
"U. S. Warplanes May Protect Burma Road Protective Force of 200 Planes,
500 Pilots Held Sufficient to Ward Off Attack by Japanese."

November 30, 1941

"Kurusu Bluntly Warned Nation Ready for Battle Foreign Affairs Expert
Attacks Tokyo Madness."

144 PEARL HARBOR ATTACK

"Leaders Call Troops Back in Singapore Hope Wanes as Nations Fail at
Parleys; Nightly Blackouts Held in P. I.; Hawaii Troops alerted."

December 1, 1941

"Japanese Press Warns Thailand."
"Burma Troops Are Reinforced British, Indian Units Arrive Rangoon."
"F. D. R. Hurries to Parleys on Orient Crisis."

December 2, 1941

"Japan Called Still Hopeful of Making Peace with U. S. Thailand Now in
Allied Bloc, Press Charges."
"Japan Gives Two Weeks More to Negotiations Prepares for Action in Event
of Failure."
"Malaya Forces Called to Full Mobilization."
"Quezon Held to Blame in P. I. Defense Delay."

December 3, 1941

"Huge Pincer attack on U. S. by Japan, France Predicted Pepper Visions
Nations Acting as Nazi Pawns."
"U S. Demands Explanation of Japan Moves Americans Prepare for Any
Emergency; Navy Declared Ready."

December 4, 1941

"Hawaii Martial Law Measure Killed for Present Session."
"Japanese Pin Blame on U. S. Army Paper Charges Violation by F. D. R."

December 5, 1941

"Probe of Japanese Activities Here Will Be Made by Senate-Spy Inquiry
Rapidly Gets Tentative O. K. By State Department."
"Pacific Zero Hour Near; Japan Answers U. S. Today."
"Japan Calls in Nationals."
"Japan Has Secret Shanghai Agents."

December 6, 1941

"America Expected to Reject Japan's Reply on Indo China Hull May Ask
Proof, Suggest Troop's Recall."
"Japan Troops Concentrated on Thai Front Military Observers Say Few
Units Have Been Posted in North."

December 7, 1941

"F. D. R. Will Send Message to Emperor on War Crisis-Japanese Deny
Massing Troops for Thai War."
"British Fear Tientsin Row, Call Up Guards May Isolate Concession to
'Prevent' Agitation over U. S.-Japan Rumors."
"Hirohito Holds Power to Stop Japanese Army."

PEARL HARBOR ATTACK 145

Honolulu Star Bulletin

November 10, 1941

"Navy Control for Honolulu Harbor."

December 1, 1941

"U. S. Army Alerted in Manila Singapore Mobilizing as War Tension
Grows."
"Japan Envoys Resume Talks Amid Tension."

December 4, 1941

"Japan Spurns U. S. Program Press Holds Acceptance Not Possible."

December 5, 1941

"Japan Parries Open U. S. Break."
"Further Peace Efforts Urged Tokyo Claims Policy 'Misunderstood' in
Washington as One of Force and Conquest."

December 6,1941

"Singapore on War Footing Sudden Order Calls Troops to Positions State
of Readiness is Completed; No Explanation Given."
"New Peace Effort Urged in Tokyo Joint Commission to Iron Out Deadlock
with U. S. Proposed."

It would seem difficult to imagine how anyone upon reading the
newspapers alone [294] could have failed to appreciate the increasing
tenseness of the international situation and the unmistakable signs of
war.[295]

THE ROLE OF ESPIONAGE IN THE ATTACK

It has been suggested that Admiral Kimmel and General Short should be
charged with knowledge that the Japanese were conducting extensive
espionage activity in Hawaii and by reason thereof they should have
exercised greater vigilance commensurate with the realization that Japan
knew everything concerning the fleet, the fleet base and the defenses
available thereto. Implicit in this suggestion is the assumption that
superior intelligence possessed by Japan concerning Pearl Harbor
conditioned her decision to strike there or,

[294] Referring to the commanding general of the Hawaiian Department,
Secretary Stimson expressed this idea in the following terms:

"Even without any such message (the War Department dispatch of November 
7) the outpost commander should have been on the alert. If he did not
know that the relations between Japan and the United States were
strained and might be broken at any time, he must have been almost the
only man in Hawaii who did not know it, for the radio and the newspapers
were blazoning out those facts daily, and he had a chief of staff and an
intelligence officer to tell him so. And if he did not know that the
Japanese were likely to strike without warning, he could not have read
his history of Japan or known the lessons taught in the Army schools in
respect to such matters." Statement of Mr. Stimson, committee record, p.
14408.
[295] Both Admiral Kimmel and General Short have made a point of the
fact that after the warnings of November 27 they were dependent on the
newspapers for information concerning the state of negotiations and from
the press, gathered that the conversations were still continuing. It is
to be recalled, however, that the "code destruction" intelligence was
made available after November 27 and indicated with unmistakable clarity
that effective negotiations were at an end. In any event it would appear
anomalous that the commanding general of the Hawaiian Department and the
commander in chief of the Pacific Fleet would permit unofficial
newspaper accounts to take precedence over official War and Navy
Department dispatches, setting forth the break-down in negotiations. 
Admiral Kimmel, himself, admitted that he did not act on newspaper
information in preference to official information supplied to him by the
Navy Department, after having previously observed that he obtained a
major portion of his "diplomatic information from the newspapers."  See
Navy Court of Inquiry record, pp. 306, 307.

146               PEARL HARBOR ATTACK

otherwise stated, that Japan would not have attacked Pearl Harbor on the
morning of December 7 if she had not the benefit of unusual and superior
intelligence. Virtually every report that has been heretofore prepared
concerning the disaster has referred to the probability of supposed
extensive espionage activity in Hawaii and the peculiar vulnerability of
the fleet base to such activity by reason of the surrounding mountainous
terrain. [296]

There is evidence before the committee, however, which reveals several
salient considerations indicating that Japanese Hawaiian espionage was
not particularly effective and that from this standpoint there was
nothing unusual about the Hawaiian situation. It is clear beyond
reasonable doubt that superior Japanese intelligence had nothing
whatever to do with the decision to attack Pearl Harbor. Among the
considerations giving rise to this conclusion are the following:

1. Radar equipment was available on Oahu for use in detecting
approaching planes. That Japan knew of radar and its capabilities would
seem clear if for no other reason than on November 22 her consul in
Panama advised her that the United States had set up airplane detector
bases and "some of these detectors are said to be able to discover a
plane 200 miles away." [297] The attacking force was actually detected
through radar over 130 miles from Oahu. Had Japanese espionage developed
the fact that radar was in use at Hawaii and so advised Tokyo of that
fact, it would seem unlikely that the attacking planes would have come
in for the raid at high altitude but, on the other hand, would have
flown a few feet above the water in order to take advantage of the radar
electrical horizon presupposing of course that Japan possessed at least
an elementary working knowledge of radar and its potentialities.

2. Perhaps the greatest single item of damage which the attacking force
could have inflicted on Oahu and our potential for effectively
prosecuting the war would have been to bomb the oil-storage tanks around
Pearl Harbor. [298] These tanks were exposed and visible from the air.
Had they been hit, inexplicable damage would have resulted. Considering
the nature of installations that were struck during the attack, it is
questionable whether Japanese espionage had developed fully the
extraordinary vulnerability of the oil storage to bombing and its
peculiar and indispensable importance to the fleet.

3. The evidence before the Committee reflects that other Japanese
consulates were supplying Tokyo as much information as the Honolulu
consulate. [299] Information supplied by the Manila and Panama consuls
was detailed in character and related meticulously to defenses available
and those in process of development. It appears that it was not until a
few days before December 7 that the Honolulu consul supplied his
Japanese superiors any significant information concerning the defenses
of Oahu, and

[296] See reports of Army Pearl Harbor Board and Navy Court of Inquiry,
committee exhibit No. 157.
[297] Committee exhibit No. 2, p. 49.
[298] Admiral Bloch pointed out that, had the Japanese attacked the oil
supply at Oahu, the dry-dock repair shop, barracks, and other facilities
instead of the airfields and the ships of the fleet, the United States
would have suffered more insofar as the prosecution of the war was
concerned. See Hart inquiry record, p. 94. It is, of course, known that
the Japanese knew generally as to the location of the oil-storage tanks
as reflected by a map recovered after the attack. See Hewitt inquiry,
exhibit No. 30.
[299] From evidence before the Committee it appears that the Manila and
Panama consuls were supplying Tokyo more information and of a type far
more indicative of an attack than that received concerning Hawaii. See
section "Ships in Harbor Reports," Part IV, infra, this report.

PEARL HARBOR ATTACK             147

at a time when the attacking force was already on its way to Pearl
Harbor. [300]

4. The Japanese task force left Hitokappu Bay on November 25 with
December 7 set as the time for the attack. This departure, it would seem
clear, was in anticipation of the failure to secure concessions from the
United States through further negotiations. The date December 7 had been
recognized as suitable for the attack in discussions prior to November
7. It is hardly credible that superior intelligence should have
precipitated or otherwise conditioned the attack when the decision to
strike on December 7 was made many days earlier and, manifestly, in the
interim between the decision and the attack date the entire defensive
situation at Hawaii could have changed. [301] As a matter of fact two of
our task forces left Pearl Harbor while the raiders were en route for
the attack.

5. It is apparent from the evidence obtained through Japanese sources
since VJ-day that the decision to attack on December 7 was made on the
basis of the general assumption that units of the fleet ordinarily came
into Pearl Harbor on Friday and remained over the week end. [302]  With
this realization providing adequate odds that substantial units of the
Pacific Fleet would-be in Pearl Harbor on Sunday, December 7, that date
was selected.

6. In February of 1941 Admiral Yamamoto is reported to have stated,

"If we have war with the United States we will have no hope of winning
unless the U. S. Fleet in Hawaiian waters can be destroyed. [303]"

This statement is clearly in line with the premise laid down by several
witnesses before the committee that Japan would open her attack on us by
hitting our Pacific Fleet wherever it might be whether at Pearl Harbor,
Manila, Panama, or on the west coast in order to immobilize it as a
threat to Japanese moves to the south. [304] The fleet happened to be
based at Pearl Harbor and in consequence that was where Japan struck.

7. The "Mori call," to which reference has heretofore been made, was on
the evening of December 5. It would appear doubtful that Japan should
have been seeking information just before the attacking the rather
inexpert manner displayed in the call if she possessed any wealth of
intelligence gleaned through espionage agents in Hawaii.

8. Investigation conducted in Japan since VJ-day indicates as a matter
of fact, that espionage agents, apart from the consul and his staff,
played no role whatever in the attack. [305] The sources of information
employed, according to Japanese interviewed, were naval attaches to the
Japanese Embassy in Washington, public newspapers in the United States,
American radio broadcasts (public), crews and passengers on ships which
put in at Honolulu, and general information. [306]

[300] See committee exhibit No. 2.
[301] Committee exhibit No. 8.
[302] Id.
[303] Committee exhibit No. 8D.
[304] See testimony of Capt. Arthur McCollum, committee record, pp.
9115-9288; testimony of Capt. Ellis Zacharias, committee record, pp.
8709-8778, 8909 9044.
[305] See committee exhibit No. 8. Also note 6, Part II, this report.
[306] Id.

148               PEARL HARBOR ATTACK

9. As late as December 2, Tokyo was solicitously asking its Honolulu
consul 

"whether or not there are any observation balloons above Pearl Harbor or
if there are any indications they will be sent up. Also advise me
whether the warships are provided with antimine nets. [307]"

On December 6, the Honolulu Consul advised Tokyo:

"In my opinion the battleships do not have torpedo nets. The details are
not known. I will report the results of my investigation. [308]"

The foregoing is hardly indicative of any superior sources or facilities
for obtaining intelligence. It is reported that the decision to employ a
horizontal-bombing attack on Pearl Harbor in conjunction with an air-
torpedo attack was for the reason that Tokyo could not determine whether
ships at Pearl Harbor were equipped with torpedo nets and the horizontal
bombing could be depended upon to inflict some damage if the torpedo
attack failed. [309]

10. In planning for the attack, Japan made elaborate precautions to
protect the raiding task force which was of itself very formidable,
probably more so as a striking force than the entire fleet based at
Pearl Harbor. A large striking force was held in readiness in the Inland
Sea to proceed to assist the raiding force if the latter were detected
or attacked. [310] It is proper to suggest that such precautions would
seem unlikely and misplaced if Japan had known through superior
espionage information that there was no air or other reconnaissance from
Oahu and the defenses were not properly alerted. The evidence reflects
that the raiding task force probably determined the extent of
reconnaissance through plotting in our plane positions with radio
bearings. Further, the Japanese force followed the broadcasts from
Honolulu commercial radio stations on the theory that if the stations
were going along in their normal manner, the Hawaiian forces were still
oblivious to developments. [311]

11. In moving in for the attack on December 7, the Japanese ran the risk
of tipping over the apple cart by sending out scouting planes a
considerable period of time ahead of the bombers. [312]  They took the
further risk of having several submarines in the operating sea areas
around Pearl Harbor. If Japan had possessed extraordinary intelligence
concerning the state of Hawaiian defenses or lack thereof, it would seem
improbable that she would have invited disaster by taking such risks.

12. Reference has been made to the large number of semiofficial consular
agents that were stationed in Hawaii, the implication being they were
engaged in widespread espionage activity Yet the facts before the
committee reflect no evidence that these agents committed a single act
of espionage, except as it may be inferred from the information sent by
the Honolulu consul to Tokyo, which as will be indicated was no more
extensive than was being received from other consulates.

[307] See committee exhibit No. 2, p. 21.
[308] Id., at pp. 27, 28.
[309] See committee exhibit No. 8.
[310] Id.
[311] See committee exhibit No. 8D.
[312] Id.

PEARL HARBOR ATTACK               149

13. It would seem likely that Japan expected some of the most effective
striking units of the Pacific Fleet, particularly the carriers, to be in
Pearl Harbor at the time of the attack. The raiders, for example, as
testified by Admiral Kimmel, bombed a vessel with lumber on its upper
deck, apparently thinking it was a carrier. In the light of
retrospection and the experiences of the war, it is suggested that Japan
would not have indulged the Pyrrhic victory of destroying our lumbering
battleships if she had not also hoped to find the fast striking units of
the fleet.

14. Japanese estimates in the late fall of 1941 as to the disposition of
United States air strength in the Pacific were, with respect to Hawaii,
as follows: Fighter planes, 200; small attack planes, 150; 4-engine
planes, 40; 2-engine planes, 100; reconnaissance and patrol planes, 35;
and flying boats, 110, for a total of 635 planes. [312a] This estimate
is roughly twice that of the actual number of planes at Hawaii and
reflects a thoroughly erroneous impression as to the ratio of planes in
a particular category. The inability to make an approximation of enemy
strength within more narrow limits of exactitude can hardly be credited
as superior intelligence.

15. In the last analysis it is difficult to believe that Japanese
espionage was actually able to develop satisfactorily the real strength
of our Pacific Fleet. In December of 1941 the Japanese fleet was
superior to our fleet in the Pacific. The latter would have been unable,
based on the testimony of witnesses questioned on the subject, to have
proceeded, for example, to the aid of General MacArthur in the
Philippines even had Pearl Harbor not been attacked. Our war plan in the
Pacific, particularly in the early stages, was essentially defensive in
character, save for sporadic tactical raids.

If the Japanese really knew the weakness of the Pacific Fleet they must
also have known that it did not present a formidable deterrent to
anything Japan desired to do in the Far East. As already suggested, the
question presents itself: *Why, if Japanese espionage in Hawaii was
superior, would Japan invite the unqualified wrath of the American
people, weld disunited American public opinion, and render certain a
declaration of war by the Congress through a sneak attack on Pearl
Harbor when the only real weapon we had, our Pacific Fleet, presented
itself no substantial obstacle to what Japan had in mind*? A logical
answer would seem to be that Japan had not been able to determine and,
in consequence, was not cognizant of our real naval weakness in the
Pacific.[312b] The extremely large raiding force and the excessive
number of attacking planes would appear to be further confirmation of
this conclusion.

[312a] See War Department memorandum dated May 21, 1946, transmitting a
letter of the same date from Commander Walter Wilds, Office of the
Chairman of the United States Strategic Bombing Survey. Committee
record, p. 14626.
[312b] When questioned as to the deterring effect the Pacific Fleet
based at Pearl Harbor in December 1941 might have on Japanese aggressive
action in the Far East, Admiral Ingersoll declared: "The Pacific Fleet
had no train, it had no transports, it did not have sufficient oilers to
leave the Hawaiian Islands on an offensive campaign and Japan knew it
just as well as we did and she knew that she could make an attack in the
area in which she did, that is, Southeast Asia and the Philippines, with
impunity." Committee record, p. 11370.

It appears that the statement by Admiral Ingersoll concerning his
estimate of Japanese knowledge concerning the capacity of the Pacific
Fleet is illogical and completely incompatible with the risks entailed
by Japan in attacking Pearl Harbor. During the war games carried on at
the Naval War College, Tokyo, from September 2 to 13, 1941, *it was
assumed that the Pearl Harbor Striking Force would suffer the loss of
one-third of its participating units; it was specifically assumed that
one AKAGI class carrier, and one SORYU class carrier would be lost*. See
committee record, p. 457.

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