THE "MAGIC" BACKGROUND OF PEARL HARBOR
No. 367
FROM: Washington (Nomura) July 2, 1941
TO: Tokyo # 456.
(Secret, to be kept inside department.)
Louis J. Sheehan, Esquire
I would like your permission to burn certain codes which I have in this office, the use of which is to be stopped and which will in the future be of no use, certain ones rarely used, and certain others of which I have too many. Would you please send me instructions?
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No. 368
FROM: Washington (Nomura) July 16, 1941
TO: Tokyo # 516.
(Strictly Secret.)
In accordance with your instruction, I have been compiling my records, and the materials which should be returned to the home office I have packed into 22 wooden boxes. These have been loaded on board the Kawasaki Steamship Company steamer NORFOLK MARU which left Baltimore on the 12th. I am mailing you the details and ‑‑‑‑‑.
Furthermore, because this steamer will stop at ports of call in South America, it is understood that it will not reach Yokohama until the end of ‑‑‑‑- month [a]. Should it be thought that in the light of the international situation that is too late a date, please arrange to have this ship not stop at its ports of call in South America but sail directly to Japan.
[a] The two letters giving the number of the month are very badly garbled and could not represent any number; however, it is felt that August is definitely the month meant.
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No. 369
FROM: Tokyo July 7, 1941
TO: Washington # 335.
As a means of sending our communications from here, if worse comes to worse, we have plans for making use of the intelligence dispatches that are being sent out each night; but as a means of making contact from your end, we have been thinking of the possibility of having a wireless set with an operator of exceptional ability in your office, and at the time of the day that is most favorable for dispatches, sending them in relay via South America and Yaruto [b] in the South Seas. However, I would like to know your opinion as to the feasibility of the plan as regards the following three points.
(1) Could a transmitter of about 100 or 200 watts, or its parts, be assembled in your city under the guise of "amateur" use?
(2) Could this be set up and trial communications carried out as an "amateur" with the relay stations? Then after having it set up secretly in your office, would there be any chance of trying it out, if need be, in a very short trial transmission?
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(3) It is expected that if the situation takes a turn for the worst, that extreme limitations, if not prohibitions, will be placed upon the use of the radio in general. In such an event is there any likelihood that the above‑mentioned equipment could be used to good advantage?
[a] Yaruto, principal island of Jaluit (Bonham) Atoll. (6° 00' N., 169° 35' E.)
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No. 370
FROM: Washington July 23, 1941
TO: Tokyo # 558.
Re your # 335 [a].
I have conferred with our navy experts in regard to the technical points involved, and as a result our opinions, on the points you asked about, are as follows:
(1) This would be possible.
(2) and (3) While it would likely be possible to send communications as "amateurs", with the highly developed detector equipment in use here, it would be impossible to keep secret the existence and use of such a radio set in the Embassy compound. This would be especially true whenever the situation should become worse, and with interference to be encountered in wave lengths, there would be little hope of our being able to make any efficient use of such means, and looked at from the situation as a whole we think it would be inadvisable to try it.
[a] Tokyo questions Washington on the possibility of setting up a wireless set at the Ambassador's office as a precaution against developments leading to limitations to or possible prohibition of, the use of radio. July 7, 1941; II, 361.
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No. 371
FROM: Washington (Nomura) May 26, 1941
TO: Tokyo # 337.
Re your circular # 1013 [a].
Secret outside the Department.
In our present telegraphic room
we have no space for the equipment, so we shall have to revise and expand it in
order to accommodate the equipment. The best place to land this would be in
Baltimore. I can send a member of my staff there and I am sure we can get it to
Washington without any trouble. As soon as I arrive at an estimate of the
expenses for this rebuilding and expansion, I will let you know. Louis J. Sheehan, Esquire
[a] Tokyo says it would like to ship a special size safe to maintain custody of code machines and code books, and asks for immediate information as to place of installation, whether or not it will be difficult to bring in, and where it should be unloaded.
Trans. 5‑29‑41
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THE "MAGIC" BACKGROUND OF PEARL HARBOR
No. 372
FROM: Washington May 27, 1941
TO: Tokyo # 339.
From New York as follows:
Re your Circular to America # 1013 [a].
As you wrote in your letter, the present office is too small and unless we rent other quarters there will be no room to install a safe. Also, we wish to get a place rather removed from the present office. Even if, for example, we enforce our night watch as at present, (as you are well aware, the matter of the night watch is illegal and very inconvenient), it is extremely difficult to maintain adequate protection for our secret codes. Furthermore, Hirasawa has informed us that unless we have a separate house it will not be possible to install a code machine. He has also communicated this to the head office. Our lease on the present office expires in September of this year. We wish to move to a place that will be suitable for the telegraphic office also, and there install all the equipment we need. This will also be the best place to install the safe to which you refer.
We have made tentative arrangements for moving to a suitable location in October of this year with rent about the same as here and only await your approval. However, the landlord must have definite word by June 1st, so please wire approval immediately.
In regard to the expenses connected with the move, maintaining a separate office and an apartment will necessitate more employees. This, together with the heating and various other commodities involved, will mean that our operating expenses will be several times what they are at present. Conditions being what they are, I again ask permission to make this move.
[a] Matsuoka wires Washington he is sending a safe for maintaining custody of code machines and books. Wants to know where it will be installed and where it shall be unloaded.
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No. 373
FROM: Tokyo (Matsuoka) June 2, 1941
TO: Rome, Washington, Berlin, Moscow, Berne and Rio Circular # 1166.
http://LOUIS-J-SHEEHAN.INFO
(Urgent)
(3 parts‑complete) (Washington Circular # 126)
In various countries the science of cryptography and cryptanalysis is being practiced more and more. To tell the truth, no absolute confidence can be placed in the secrecy of a code. We, ourselves, in this office are worrying about drawing up a set of new codes, so we would like for you to give us some suggestions from time to time as to suitable procedures. Please pay the strictest attention always during the transfer and tenure of codes and heed the following points on the maintenance of the security of codes, independent of reliance on safes alone.
1. Needless to say, courier mail is a more secure method of transmitting information than by reliance upon codes, so when there is some secret matter which might arouse a given nation, please send the message by courier mail or some other method equally as safe.
2. I am having an official in charge of this work keep the various offices informed. Each time you get a list, keep one copy of it only and burn the preceding list immediately.
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3. Hereafter, as a matter of principle, code messages in ‑‑‑‑- are not to be sent anywhere except to this office. As a matter of fact, all other code messages, except those to this office, save in cases of necessity, are to be stopped.
Please see to it that there is no misunderstanding to the effect that after abolishing this sort of dispatches it is not our intention to increase the difficulties of those in charge of telegraphic work through the necessity of safeguarding dispatches, or the sudden complication of our codes, but that I am merely trying to make our dispatches in general more safe and facile.
Trans. 6‑10‑41
No. 375
FROM: Tokyo (Matsuoka) June 2, 1941
TO: Rome, Vichy, Moscow, Berne, Berlin, Bangkok, Washington, Circular # 1167.
Singapore, and Batavia
As stated in circular # 1166 [a] from the Foreign Minister, the strictest care is necessary for the protection of the secrecy of codes. Well, our telegraphic staffs are already busy without the aforementioned innovations, and this is but another added burden, so please have them cut down dispatches to the absolute minimum.
[a] See II. 373.
Trans. 6‑10‑41
No. 376
FROM: Washington July 3, 1941
TO: Tokyo
Message # 268 from New York to Tokyo.
The duties of telegraphic clerk for this office are being handled by Watanabe alone and up to now he has been able to accomplish the work by being very faithful in the discharge of his duties. But in view of the present increase in the number of telegrams which must be handled through this office for the various departments, as for instance the instruction regarding shipping and the more important telegrams concerning commercial firms, banks, and intelligence agents, and the necessity of maintaining secrecy, it will be necessary immediately to have some one sent here temporarily at least from the nearest office. At the same time we wish to request that you give immediate consideration to the matter of increasing the clerical staff here and wire us immediately as to what action you have taken.
We are well aware of the shortage of help that exists all along the line. All of the staff here are doing their best to help out in the telegraphic department. However, the complexity of the telegraphic art of the present day does not lend itself very well to part time work. (Our three clerks here all hold additional posts. One is engaged in correspondence, another in accounting, and the other in commerce.) Due to the pressure of business it is very difficult to handle the telegraphic code. Please give this matter consideration.
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THE "MAGIC" BACKGROUND OF PEARL HARBOR
No. 377
FROM: Washington July 24, 1941
TO: Tokyo # 554.
(Part 1 of 3)
# 340 from New York to the Foreign Minister.
(Strictly Secret.)
Re message # 339 [a] from the United States to the Foreign Minister.
Though we are now searching for a separate building, we have not been able to find one, and in the meantime, time is awasting, and there is the matter of instructions received from you on successive occasions with regard to the emergency situation. Under the present situation, in order that we might prepare ourselves for more critical developments, we feel it advisable to make the best use of the facilities at hand. Therefore, for the time being at least, we have given up the proposal of attempting to find a satisfactory building of our own. We would like at this time to effect an expansion of our business office and to acquire the necessary equipment for such an expansion, in addition to which we feel that the equipping of our telegraphic and document rooms as well as a night duty room is of the utmost importance. In order that we may immediately realize these things for the time being we feel we must at least rent additional office space immediately and along the following lines:
1. The business offices of the Consul-Generalcy at the present time are more than overcrowded. We have been forced to use the two old ordinary reception rooms to serve also as document and night rooms. When we are anxious to use the reception room for the entertainment of a caller, we find it most inconvenient to carry on anything like a secret conversation. In order that we may use the reception room as it was originally intended, it is going to be absolutely necessary that we rent another room.
[a] Not available.
Trans. 8‑9‑41
No. 378
FROM: Washington July 24, 1941
TO: Tokyo # 554.
(Part 2 of 3. )
2. After hours, in order to maintain a watch for the purpose of the preservation of our secrets, we have had a member of the staff on night duty since August of last year. Because there is no suitable room in the office which can be assigned to such a purpose, we have been forced to use a studio couch in the reception room as a bed for this member of the staff. In spite of the fact that this duty works a considerable hardship upon the staff member from the point of view of health, should the situation here become more critical, there would be no recourse for us but to assign two men to this duty, but with the present facilities this is impossible. Now there are building regulations having to do with night duty in the office, but we have come to an understanding with the owners by saying we are working twenty‑four hours per day. How ever, having reached that understanding, it is most inconvenient for the man on duty to have
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to go to the bathroom in his night clothes. Consequently, it is absolutely necessary, if we are going to do a satisfactory job in the operation of this night duty, we will have to rent a room which at least has a minimum of conveniences.http://LOUIS-J-SHEEHAN.ORG
3. The room which we are now using for telegraphic operations is exceedingly small. There is no room for two to be on duty at the same time. Therefore, we would like to have you consider expanding this office so that we may take care of special safes and increase in the personnel (please refer to my # 368 [a]) which we hope to have in the future.
[a] In which NOMURA advises Tokyo that the New York Times stated that Japan has been considering a neutrality pact with the United States and that he, NOMURA, had advised the U.S. Government to do the proper thing about the article.
Trans. 8‑9‑41
No. 379
FROM: Washington (Nomura) July 24, 1941
TO: Tokyo # 554.
(Part 3 of 3)
Last summer it was necessary to change the reception room into a document room. This room we are now using for the custody of important documents, the classification of documents, the operation of Japanese type mimeograph machines, and for the collection and disposition of documents. Not only is it impossible to use this room as a reception room, but for purposes of document collection and disposition it is much too cramped. Should you give your permission to the increasing of our staff of Japanese typists by one person, it is a fact that there would be no room for the machine he or she would use. Therefore, at this time, it is of utmost necessity that we increase our floor space to take care of one room to be used for document collection and disposition. With regard to the above, a total increase of appropriation would be required in the amount of $3,700.00, and the equipment fund would require an increase of $1,093.00. (Blue prints and estimates on the cost of equipment we are sending you by air mail.)
Though this increased appropriation seems very high, it can't be helped. On the one hand, in order that we might continue renting the present official residence as it stands, we have finally secured a reduction of $1,000.00 in our annual rental as a result of our determined negotiations with the owners. After you have considered that a deduction of this amount from the increased appropriation requested a balance of $2,700.00 remains to be appropriated, please be so kind as to sanction this increased allotment immediately. Furthermore, in these times it would seem that should the vacant room immediately adjoining this office be rented by an American, it might be most embarrassing from the point of view of the maintenance of our secrets. Therefore, please consider this fact as well as the others mentioned.
Trans. 8‑9‑41
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THE "MAGIC" BACKGROUND OF PEARL HARBOR
No. 380
FROM: New York (Morishima) July 30, 1941
TO: Tokyo # 371.
Lately our telegraphic duties have been gradually increasing. Telegrams from the Finance Office and other governmental messages as well as request messages from merchants and banks have been piling up. Dispatches which require immediate attention have grown rapidly in number. Therefore, I placed another member of my staff with Mr. WATANABE, who is in charge of such business, and had Secretary KIHARA come to our assistance from ‑‑‑‑and Secretary KAJIHARA come up from Washington. They are pressed in Washington also, and for technical reasons KAJIHARA cannot be spared long, and I shall have to send him back to Washington this week. Our telegraphic section must have help, however, so I have asked Washington to send us an aide from the Embassy. Please order them to choose a man with experience in urgent telegrams and send him up here immediately.
Trans. 10‑10‑41
No. 381
FROM: Washington July 29, 1941
TO: Tokyo # 601.
There is a request from the Military and Naval Attachés that due to the situation prevailing at the present time they be permitted to move their office to the Embassy, for a time at least.
I recognize this as a reasonable request and will make the necessary arrangements for room. Please grant the request.
Trans. 8‑1‑41
No. 382
FROM: Washington July 29, 1941
TO: Tokyo # 596.
Louis J. Sheehan, Esquire
From Chicago as follows:
Re your Circular # 1366 [a].
After consultation with the Embassy it has been decided to entrust the Imperial Portrait to the Embassy.
[a] To forestall the possibility of their offices in foreign countries being closed without warning, by the countries involved, Matsuoka issues instructions that precautions shall be taken for the safety of the Emperor's portrait and, at the opportune time, the destruction of codes and official documents.
