47 Mr R. G. Casey, Minister to the United States, to Department of External Affairs
Cablegram 642 WASHINGTON, 15 August 1941, 7.41 p.m.
I saw the Secretary of War' today and stressed the significance of Thailand and of reinforcing the Philippines as in my telegram No.
634.2 Whilst broadly agreeing he is one of those whose attention is concentrated on Europe and the Atlantic theatre. However, he told me that the United States had now decided to reinforce the Philippines, in addition to the heavy bomber squadron referred to in my telegram No. 591  the extent of which I subsequently found to be 50 tanks, 50 anti-tank guns and 50 fighting aircraft.
[I understand this reinforcement will leave in next fortnight.] 
In addition to the above I understand that further reinforcement of one division and one anti-aircraft regiment is being considered although shipping shortage is a factor in this regard.
There seems to be a noticeable change in the attitude regarding the Philippines. From believing the Philippines could not be held against Japanese attack (see last paragraph my telegram 328 May 2nd ) United States Army now seems to believe that with the above-mentioned reinforcement the Philippines could be held.
Reference my telegram 562 , I learn most confidentially that United States Navy will take over the protection of all British merchant shipping from North America to Iceland about September 1st thereby releasing the Royal Navy forces for other duties and other theatres.
I believe at one or other Conferences at Singapore six or nine months ago the matter of the occupation of Kra Isthmus between Burma and Malaya by British troops and Air Force was discussed, if and when the Japanese entered Thailand from Indo-China. No doubt the possibility of this operation is being again considered in the light of Prime Minister's  telegram No. 91.