A RTA Type 95 Ha-Go on the advance in the Shan States, 1942.
5 May 1942 from Foreign Minister (Tokyo) to Japanese Ambassador (Bangkok), No. 575
According to a message received from our Military Attaché in Bangkok, PHIBUN, who for some time has been complaining that to leave the Thai army which has been stationed on the north border to face the coming rainy season with no activity in view, would result in the incease in unrest, in the discontented parties in Thailand, and especially among the Military, which might even become the cause of making his own position insecure, requested the following of our Attaché on April 30th.
He wishes at this time to immediately carry out an attack in the northern territory east of the SALWEEN RIVER and advance to the Chinese border.
He believes that the Thai Army can make an attack on the Chinese army here with no assistance, and that it is not necessary for them to wait on shipment of armanent from Japan, that they can start operations immediately.
After the war he wishes that we give the Thais the territory east of the SALWEEN RIVER.
In regard to the above the Attaché said that according to the published statement of TOJO (Burma) was to be given independence in the future and so to make this area a part of Thailand would be very difficult.
PHIBUN said, in that case could not this area be made a small independent country like Luxemburg.
The Attaché's opinion in regard to the above it might be well to give the area north of the SALWEEN RIVER to Thailand, or even if it were made an independent country as PHIBUN suggested there would be no complaint. In either case though as far as PHIBUN is concerned, if the Army which he has transferred for the attack and which he says is ready to carry out an independent offensive is not used at this time for that purpose before they lose their spirit, there is great danger that the discontent generated may be as to threaten the existence of the PHIBUN administration.
I think this matter might well be handled as a joint Japanese-Thai Campaign and as PHIBUN and the Military Attaché there have talked, the matter of restoration of territory will have to be handled as a separate problem. It will be necessary for us to consider the problem of restoration of territory together with our policy toward Burma. So please keep this matter secret to yourself, ascertain in some secret manner just how much fever PHIBUN has for this matter, and wire by return dispatch.