The Naval Court of Inquiry treated intercepted, decoded Japanese messages separately from its main opinion. Hereafter is the Addendum (dated October 19, 1944) to the Court's Findings of Fact.
Addendum to [Navy] Court's Finding of Facts [October 19, 1994].
From Pearl Harbor Attack, Part 39, pp. 323-30.
In the Finding of Facts, No. XVIII, the Court had referred to "certain
other important information" as being available to the War and Navy
Departments. This information was obtained by intercepting Japanese
messages and breaking their diplomatic codes. The Court has been
informed that these codes are still in use and, if it became known to
the Japanese Government that they had been broken by the United States,
the codes would be changed and, as a consequence, the war effort would
be adversely affected.
For this reason, the Court has refrained from analyzing or discussing
the details of the information in its Finding of Facts but feels that
its report would not be complete without a record of such details. The
Court, therefore, submits the following record in this addendum and
transmits it to the Secretary of the Navy for filing with other highly
secret matter referred to as such in the record of the Court's
proceedings.
Highly secret messages, hereinafter mentioned, were intercepted by the
War and Navy Departments during the very critical period 26 November to
7 December, 1941, and prior thereto. The method of handling these
messages in the Navy Department was as follows:
The Director of Naval Intelligence and the Director of Naval
Communications operated directly under the Chief of Naval Operations.
They were responsible to see that all messages were transmitted to him
in order that he might be kept conversant at all times with existing
conditions.
Officers in Intelligence and Communications, Divisions of Naval
Operations, remained on duty night and day. They made every effort to
obtain all possible diplomatic and military information, in order that
high officials of our government might be kept fully informed.
Messages were translated and placed in a folder immediately upon receipt
or intercept. The important messages were marked with a clip and taken
by a designated officer to the Secretary of the Navy, the Chief of Naval
Operations, the Directors of War Plans, Naval Intelligence, and Naval
Communications, and to the Chief of the Far Eastern Division of Naval
Intelligence. The Director of Naval Intelligence, Captain Wilkinson,
kept himself constantly informed regarding all messages. He checked as
to whether or not the Chief of Naval Operations had seen the important
ones and in many cases took them personally to the Chief of Naval
Operations and discussed them with him.
Immediately after the receipt of the note of 26 November, 1941, from the
Secretary of State, the Japanese representatives in Washington sent a
message to Tokyo which was intercepted by the Navy Department. This is
Document 17, Exhibit 63, which gave Tokyo the following stipulations
contained in the note:
(a) The recognition of Hull's "four principles".
(B) (1) Conclusion of mutual non-aggression treaty between Tokyo,
Moscow, Washington, The Netherlands, Chungking and Bangkok.
(2) Agreement between Japan, United States, England, The Netherlands,
China and Thai on the inviolability of French Indo-China and equality of
economic treatment in French Indo-China. (3) Complete evacuation of
Japanese forces from China and all French Indo-China.
(4) Japan and the United States both definitely to promise to support no
regime but that of Chiang Kai-shek.
(5) The abolition of extraterritoriality, the concessions in China, and
other requirements bearing on reciprocal trade treaty, rescinding
freezing orders, stabilization of yen, etc., and for Japan to amend her
tripartite pact with Germany and Italy.
The Japanese representatives added in their report to Tokyo, the
following:
"Both dumbfounded and stated to Hull we could not even cooperate to the
extent of even reporting this to Tokyo."
No information regarding the delivery of this note or of its contents
was transmitted to the Commander-in-Chief, Pacific Fleet, or to other
commanders afloat.
From 26 November to 7 December, 1941, there was much diplomatic dispatch
traffic intercepted between Tokyo and the Japanese Ambassador in
Washington which had a bearing on the critical situation existing and
which was not transmitted to the Commander-in-Chief, Pacific. A message
dated 19 November, 1941, Tokyo to Washington, translated on 28 November,
1941, and referred to as "The Winds Code" was as follows:
"Regarding the broadcast of a special message in an emergency.
"In case of emergency (danger of cutting off our diplomatic relations),
and the cutting off of international communications, the following
warning will be added in the middle of the daily Japanese language short
wave news broadcast.
"(1) In case of a Japan-U.S. relations in danger: HIGASHI NO KAZEAME.
[East wind rain.]
"(2) Japan-U.S.S.R. relations: KITANOKAZE KUMORI. [North wind cloudy.]
"(3) Japan-British relations: NISHI NO KAZE HARE. [West wind clear.]
"This signal will be given in the middle and at the end as a weather
forecast and each sentence will be repeated twice. When this is heard
please destroy code papers, etc. This is as yet to be a completely
secret arrangement.
"Forward as urgent intelligence."
The Commander-in-Chief, Asiatic Fleet, on 28 November, 1941, sent to the
Chief of Naval Operations, information to Commander-in-Chief, Pacific
Fleet; Commandant 16th Naval District; and Commandant 14th Naval
District, substantially the same information as outlined above. On 5
December, 1941, the United States Naval Attach, Batavia, sent to the
Chief of Naval Operations substantially the same information. These
messages stated that at some future late information would be sent by
Japan indicating a breaking off of diplomatic relations or possibly war
between countries designated.
All officers of the Communication and Intelligence Divisions in the Navy
Department, considering the expected information most important, were on
the lookout for this notification of Japanese intentions. On 4 December
an intercepted Japanese broadcast employing this code was received in
the Navy Department. Although this notification was subject to two
interpretations, either a breaking off of diplomatic relations between
Japan and the United States, or war, this information was not
transmitted to the Commander-in-Chief, Pacific Fleet, or to other
Commanders afloat.
It was known in the Navy Department that the Commanders-in-Chief,
Pacific and Asiatic Fleets, were monitoring Japanese broadcasts for this
code, and apparently there was a mistaken impression in the Navy
Department that the execute message had also been intercepted at Pearl
Harbor, when in truth this message was never intercepted at Pearl
Harbor. No attempt was made by the Navy Department to ascertain whether
this information had been obtained by the Commander-in-Chief, Pacific,
and by other Commanders afloat.
Admiral Stark stated that he knew nothing about it, although Admiral
Turner stated that he himself was familiar with it and presumed that
Admiral Kimmel had it. This message cannot now be located in the Navy
Department.
It is a matter of general knowledge that Japan has had for many years a
thorough system of espionage throughout the world and continuously
sought and received information regarding the location and movements of
United States naval vessels. There were certain messages received in the
Navy Department which showed very clearly that Japan, at this critical
period, was particularly desirous of obtaining exact information from
two sources, namely, Manila and Honolulu. Messages between Tokyo,
Manila, and Honolulu inquiring especially about planes, ships, their
places of anchorage, etc., in the latter ports, were intercepted.
Similar messages were sent to Japanese officials in Honolulu clearly
indicating that Japan was most desirous of obtaining exact information
as to ships in Pearl Harbor.
The important messages having special reference to Pearl Harbor were as
follows:
(a) On 15 November, 1941, Document 24, Exhibit 63, an intercept from
Tokyo to Honolulu, translated in Navy Department, 3 December, 1941,
states:
"As relations between Japan and the United States are most critical make
your "ships in harbor report" irregular but at rate of twice a week.
Although you already are no doubt aware, please take extra care to
maintain secrecy."
(b) On 18 November, 1941, Document 37, Exhibit 63, an intercept from
Tokyo to Honolulu, translated in Navy Department on 5 December, 1941,
states:
"Please report on the following areas as to vessels anchored therein:
Area "N" Pearl Harbor, Manila Bay, and areas adjacent thereto. Make your
investigation with great secrecy."
Note by Navy Department on this message:
"Manila Bay" probably means "Mamala Bay."
(c) On 18 November, 1941, Document 40, Exhibit 63, an intercept from
Honolulu to Tokyo and translated in Navy Department 6 December, 1941,
gives information as to ships moored in certain areas in Pearl Harbor
and movements of ships in and out.
(d) On 29 November, 1941, Document 36, Exhibit 63, an intercept from
Tokyo to Honolulu, translated in Washington 5 December, 1941, states:
"We have been receiving reports from you on ship movements but in future
will you also report even where there are no movements."
Admiral Kimmel was not aware of and had no information regarding these
messages.
On 5 November, 1941, Document 7, Exhibit 63, Tokyo to Washington, was
intercepted. This message stresses the necessity of signing an agreement
between the United States and Japan by 25 November, 1941.
On 22 November, 1941, Document 11, Exhibit 63, intercept from Tokyo to
Washington, stated that the signing of agreement set for 25 November,
1941, could be postponed until 29 November, and in explanation this
message stated:
"* * * There are reasons beyond your ability to guess why we wanted to
settle Japanese-American relations by the 25th, but if within the next
three or four days you can finish your conversations with the Americans;
if the signing can be completed by the 29th, * * * if the pertinent
notes can be exchanged; if we can get an understanding with Great
Britain and the Netherlands; and in short if everything can be finished,
we have decided to wait until that date. This time we mean it, that the
deadline absolutely cannot be changed. After that things are
automatically going to happen. * * *"
No intimation of the receipt of this message was transmitted to the
Commander-in-Chief, Pacific, or to other Commanders afloat, nor was any
information transmitted to them regarding contents of the messages
mentioned in the following paragraphs.
On 28 November, 1941, a dispatch, Document 18, Exhibit 63, was
intercepted between Tokyo and Washington which in part reads as follows:
"* * * The United States has gone ahead and presented this humiliating
proposal "
referring to note of 26 November
"* * * the Imperial Government can by no means use it as a basis for
negotiations. Therefore, with a report of the views of the Imperial
Government on this American proposal which I will send you in two or
three days, the negotiations will be de facto ruptured. This is
inevitable. However, I do not wish you to give the impression that the
negotiations are broken off. Merely say to them that you are awaiting
instructions * * *"
etc.
The message indicates the position of Japan regarding the note of 26
November, and further indicates that within two or three days
negotiations will be de facto ruptured. Further, it emphasizes the
importance of delay. Neither the message nor any of its contents were
transmitted to the Commander-in-Chief, Pacific, or to other Commanders
afloat.
On 29 November, 1941, Document 19, Exhibit 63, intercept Tokyo to
Washington and translated by the Navy Department 30 November, 1941,
directs that Japanese representatives make one more attempt to have
United States reconsider and states:
"* * * please be careful that this does not lead to anything like a
breaking off of negotiations."
Again, on 30 November, 1941, Document 20, Exhibit 63, an intercept from
Washington to Tokyo indicated that negotiations were to be stretched
out.
These two messages indicate that the Japanese were sparring for time.
On 30 November, 1941, Document 22, Exhibit 63, translated by the Navy
Department on 1 December, 1941, was intercepted, being a message from
Tokyo to Japanese representatives in Berlin, reading as follows:
"1. Japan-American negotiations were commenced the middle of April of
this year. Over a period of half a year they have been continued. Within
that period the Imperial Government adamantly stuck to the Tri-Partite
Alliance as the cornerstone of its national policy regardless of the
vicissitudes of the international situation. In the adjustment of
diplomatic relations between Japan and the United States, she has based
her hopes for a solution definitely within the scope of that alliance.
With the intent of restraining the United States from participating in
the war, she boldly assumed the attitude of carrying through these
negotiations.
"2. Therefore, the present cabinet, in line with your message, with the
view of defending the Empire's existence and integrity on a just and
equitable basis, has continued the negotiations carried on in the past.
However, their views and ours on the question of the evacuation of
troops, upon which the negotiations rested (they demanded the evacuation
of Imperial troops from China and French Indo-China), were completely in
opposition to each other.
"Judging from the course of the negotiations that have been going on, we
first came to loggerheads when the United States, in keeping with its
traditional ideological tendency of managing international relations,
re-emphasized her fundamental reliance upon this traditional policy in
the conversations carried on between the United States and England in
the Atlantic Ocean. The motive of the United States in all this was
brought out by her desire to prevent the establishment of a new order by
Japan, Germany, and Italy in Europe and in the Far East (that is to say,
the aims of the Tri-Partite Alliance). As long as the Empire of Japan
was in alliance with Germany and Italy, there could be no maintenance of
friendly relations between Japan and the United States was the stand
they took. From this point of view, they began to demonstrate a tendency
to demand the divorce of the Imperial Government from the Tri-Partite
Alliance. This was brought out at the last meeting. That is to say that
it has only been in the negotiations of the last few days that it has
become gradually more and more clear that the Imperial Government could
no longer continue negotiations with the United States. It became clear,
too, that a continuation of negotiations would inevitably be detrimental
to our cause.
"3. The proposal presented by the United States on the 26th made this
attitude of theirs clearer than ever. In it there is one insulting
clause which says that no matter what treaty either party enters into
with a third power it will not be interpreted as having any bearing upon
the basic object of this treaty namely the maintenance of peace in the
Pacific. This means specifically the Three-Power Pact. It means that in
case the United States enters the European war at any time the Japanese
Empire will not be allowed to give assistance to Germany and Italy. It
is clearly a trick. This clause alone, let alone others, makes it
impossible to find any basis in the American proposal for negotiations.
What is more before the United States brought forth this plan, they
conferred with England Australia, The Netherlands, and China they did so
repeatedly. Therefore, it is clear that the United States is now in
collusion with those nations and has decided to regard Japan, along with
Germany and Italy, as an enemy."
On 1 December, 1941, the Navy Department intercepted a message from
Tokyo to the Japanese Ambassador in Berlin as follows:
"The conversations between Tokyo and Washington now stand ruptured. Say
very secretly to Hitler and Ribbentrop that there is extreme danger that
war may suddenly break out between the Anglo Saxon nations and Japan and
this war may come quicker than anybody dreams. We will not relax our
pressure on the Soviet, but for the time being would prefer to refrain
from any direct moves on the north. Impress on the Germans and Italians
how important secrecy is."
On 1 December, 1941, Document 21, Exhibit 63, was intercepted, being a
message from Tokyo to the Japanese Ambassador in Washington which reads
as follows:
"1. The date set in my message #812 has come and gone, and the situation
continues to be increasingly critical. However, to prevent the United
States from becoming unduly suspicious we have been advising the press
and others that though there are some wide differences between Japan and
the United States, the negotiations are continuing. (The above is for
only your information).
"2. We have decided to withhold submitting the note to the U.S.
Ambassador to Tokyo as suggested by you at the end of your message
#1124. Please make the necessary representations at your end only.
"3. There are reports here that the President's sudden return to the
capital is an effect of Premier Tojo's statement. We have an idea that
the President did so because of his concern over the critical Far
Eastern situation. Please make investigations into this matter."
On 2 December, 1941, Document 25, Exhibit 63, intercept Washington to
Tokyo, translated by the Navy Department 3 December, 1941, reports that
conversations with the State Department continue; that the Japanese
representatives stated to Welles, the Under Secretary of State, that it
is virtually impossible for Japan to accept new American proposals as
they now stand, and that the Japanese representatives feel that the
United States is anxious to peacefully conclude the current difficult
situation.
On 3 December, 1941, Document 29, Exhibit 63, intercept Tokyo to
Washington, translated by the Navy Department 4 December, 1941, requests
their representatives to explain Japan's increased forces in Indo-China.
On 3 December, 1941, Document 33, Exhibit 63, intercept Washington to
Tokyo, translated by Navy Department 5 December, 1941, states:
"Judging from all indications, we feel that some joint military action
between Great Britain and the United States, with or without a
declaration of war, is a definite certainty in the event of an
occupation of Thailand."
On 6 December, 1941, Document 38, Exhibit 63, from Tokyo to Washington,
was intercepted, giving notice to the Japanese representatives that a
reply consisting of 14 parts to American proposal of 26 November is
being sent to them, directing that secrecy should be maintained and
stating that the time of presenting this reply would be sent in a
separate message.
The first 13 parts of this reply were intercepted and received by the
Navy Department at about 3:00 p.m., December 6, 1941, and were
translated and made ready for distribution by 9:00 p.m., Washington
time, of that date. These 13 parts contain a very strong and conclusive
answer to the note of November 26 and state in part,
"Japan cannot accept proposal as a basis of negotiations."
Commander Kramer, the officer whose duty it was to distribute this class
of information, prior to 9:00 p.m., 6 December, 1941, 'phoned Captain
Wilkinson that an important message had been received and was being
translated. He also tried to communicate with Admiral Stark and Rear
Admiral Turner at their homes but found them out.
At about 9:00 p.m., Washington time, Commander Kramer proceeded to the
White House with the 13 parts of reply and delivered a copy to a White
House aide, with the request that it be delivered immediately to the
President. Kramer then proceeded to the home of Secretary Knox where he
personally delivered to the Secretary a copy of the Japanese reply.
Secretary Knox read the reply, did not discuss it in detail with Kramer,
but 'phoned the Secretary of War and Secretary of State.
Kramer then proceeded to the home of Captain Wilkinson and gave a copy
to him. Kramer told Wilkinson that he had tried to get Stark and Turner.
Wilkinson made several 'phone calls, presumably to Admiral Stark and
others. This information regarding receipt of these 13 parts or their
contents was not transmitted to the Commander-in-Chief Pacific Fleet or
other Commanders Afloat.
Kramer then returned to his office in the Navy Department, arriving
about 12:30 a.m., 7 December, and as no other important messages were at
hand, went home and returned to the Navy Department about 7:00 a.m. Upon
his arrival he found the 14th part of the Japanese reply had been
received and decoded. He then delivered a copy of all 14 parts to the
Flag Secretary in his office of the Chief of Naval Operations at about 9
a.m., where he found several officers gathering for a conference with
Admiral Stark. Kramer then proceeded, about 9:30 a.m., to the White
House and made delivery of the 14 parts of the message. He proceeded
then, at about 9:50 a.m., to the State Department and delivered same to
the Secretary of the Navy, who was there in conference with the
Secretary of State.
At about 10:30 a.m., Kramer returned to the Navy Department where he
found another message had been translated. This message, an intercept
from Tokyo to Washington, was marked "Urgent, very important" and read
as follows:
"Will the ambassador please submit to the U.S. Government (if possible
to the Secretary of State) our reply to the U.S. at 1:00 p.m., on the
7th, your time."
Kramer delivered a copy of this message (hereinafter referred to as the
"one p.m. message") to the Flag Secretary of Admiral Stark, the latter
at the time being in conference with several officers.
Kramer then returned to the White House and delivered the "1:00 p.m.
message." From there he went to the State Department where the Secretary
of the Navy was still in conference with the Secretary of State. On
arrival he requested one of the State Department assistants to present
the message to the Secretary of the Navy and to invite his attention to
the fact that 1:00 p.m., Washington time, meant dawn at Honolulu and
midnight in East Asia.
Admiral Stark had arrived in his office at the Navy Department at some
time between 9:00 and 10:30 a.m., on the morning of 7 December. Although
he testified that he had no information prior to this time relative to
the Japanese reply to the note of November 26th he was informed of the
14 parts and "the 1:00 p.m. message" not later than 10:30 a.m., of that
date. He testified that General Marshall 'phoned him and suggested that
the information regarding the delivery of the 14 parts at 1:00 p.m. was
most important and significant and, in his opinion, should be
transmitted to Commanders in the Pacific. Admiral Stark at first
demurred and hung up the receiver. Shortly thereafter he 'phoned General
Marshall requesting that, in the event he sent the message to the
Commanding Generals in the Pacific area, he instruct them to relay this
message to naval opposites.
The message which General Marshall sent to the Commanding General,
Hawaiian Department (Exhibit 48) reads as follows:
"Japanese are presenting at one p.m. Eastern Standard Time today what
amounts to an ultimatum also they are under orders to destroy their Code
machine immediately stop Just what significance the hour set may have we
do not know but be on alert accordingly stop Inform naval authorities of
this communication."
This message left the War Department at 11:52 a.m., Washington time, was
sent out over R.C.A. at 12:17 p.m. (6:47 a.m. Honolulu time) and arrived
in Honolulu's R.C.A. office at 7:33 a.m. Honolulu time. There remained
but 22 minutes before the attack for delivery, decoding, dissemination,
and action. Lieut. General Short did not receive the decoded dispatch
until the afternoon of 7 December, several hours after the attacking
force had departed.
Had the telephone and plain language been used, this message could have
been received in Hawaii before the attack began. Even in this event,
however, there was no action open to Admiral Kimmel which could have
stopped the attack or which could have had other than negligible bearing
upon its outcome. There was already in effect the condition of
readiness best suited to circumstances attending vessels within the
limits of the Pearl Harbor Naval Base and the Fleet planes in their air
bases in Oahu.
Orin G. Murfin,
Admiral, U.S. Navy (Ret.)
President.
Edward C. Kalbfus,
Admiral, U.S. Navy (Ret.)
Member.
Adolphus Andrews,
Vice Admiral, U.S. Navy (Ret.)
Member.
Credits
Online, courtesy U.S. National Archives.
