740.0011 European War 1939/16438: Telegram
The Ambassador in Japan (Grew) to the Secretary of State
[Received November 7—12:45 a.m.]
1759. Department’s 713, November 3, 11 p.m.82a The Department will no doubt appreciate the difficulty of our assessing the accuracy of reports from sources with which we are not in contact. The question of the weight which might be attached to such reports depends in considerable measure on the accuracy of previous reports from the same sources, on the degree to which such sources might or might not be interested in the propagating of alarmist reports of movements on the part of Japanese forces, and on other factors. We at this Embassy are constantly on the alert for indications of future Japanese military operations in new theatres, such forecasts as we have made have been substantially accurate, and we will continue to communicate immediately to the Department any developments or credible reports presaging Japanese military operations in new theatres.
With regard to the “second and third” official view cited in the Department’s telegram under reference, that Japanese offensive in eastern Siberia would occur by November 4, obviously requires no comment. We have under study the question of Japanese relations with Soviet Russia and we expect to despatch a telegram on this subject in the near future.83
With regard to the first and second “official view” we have ourselves reported to the Department that the Japanese are pressing the French to provide accommodations for an increase to about 75,000 men of the [Page 571] Japanese forces in Tongking. A high Japanese official, apparently by inadvertence, disclosed to me on October 10 that the mission of this large force would be to invade Yunnan from Indochina, to interrupt the sending of supplies to China from Burma. This was probably the plan under consideration at that time, but we must not exclude the possibility that the apparent inadvertence may have been carefully planned as a feint to distract attention from plans for an attack elsewhere. The French Military Attaché in Tokyo ridicules the possibility of a successful attack on Yunnan from Indochina, the character of the terrain precluding any large scale operations, and he affirms that the reinforcements are intended for an attack on Thailand. Our Naval Attaché was recently told by an informant whom he considers trustworthy that the Japanese are prepared to attack Thailand. The Department will recall (Department’s 685, October 22, noon84) that it received a substantially similar report which originated from a source thought to be well-informed.
In the absence of tangible evidence of preparations for military operations, such as concentrations of troops and supplies, movements of transports, and so on, the only way in which we can assess the accuracy of reports such as those above cited is to determine whether or not predicted Japanese attacks as of specified future dates in new areas fit in with Japanese political objectives as modified from time to time by changing conditions.
The efforts of Japan to reach an understanding with the United States are clear evidence that the progressive deterioration of her economic and industrial strength is becoming the controlling factor. The recent economic measures taken against Japan by the United States and other countries have made Japan exclusively dependent on her reserves for most of the primary materials necessary for the conduct of war. She has lost the greater part of her foreign trade, her industries are running down, and her financial resources are approaching depletion. If her conflict with China is long continued, her reserves will have become diminished if not exhausted.
Japan today is on the one hand seeking to extricate herself by peaceful means from the position in which she finds herself, and on the other hand preparing, in the event of failure to emerge peacefully from that position, to seize that area which will provide the raw materials which she will most need, notably oil, tin and rubber. The area within which there exist in substantial quantities many of the most important of the primary materials is the Southwest Pacific. Whether or not Japan when confronted with the need for making a decision, will attack in that area is a matter of opinion.
We therefore conclude that undue importance should not be attached to dates specified for future Japanese military operations, but that a [Page 572] more reliable indication of the probabilities of Japanese military movements is offered by the progress or failure of the exploratory conversations with the American Government and of other developments in the political field.
The Military Attaché and, in the absence of the Naval Attaché, the Assistant Naval Attaché concur in the above.
The Department may wish to review our 1015, July 17, 11 a.m.85 Important developments have since occurred but may, for the considerations put forward in that telegram, well be found relevant in the present circumstances.