Cablegram unnumbered 1 June 1940,
PERSONAL MOST SECRET
Your 365 and 366. [1] I have had no views yet from the United Kingdom on your memorandum. In meantime Casey [2] has personally communicated my appeal to the President [3] whose views have been sent to you and Churchill. [4] We have now received from Casey record of important talk with Sumner Welles on 30th May. [5] Casey emphasised our point of view of possibility of French collapse especially if Italy intervened, then threat to Britain of overwhelming air and land attack, and grave danger to United States by elimination or capitulation of British Navy. Casey stated he firmly believed time when material assistance from United States would be of use was passing and that declaration by United States soon would be the only thing that could save the world.
Welles said logic of situation was that British Fleet ceasing to exist was against vital interests of the Dominions, that Casey had painted graver future than he had conceived. Eventually he accepted as genuine views of Casey and agreed to speak to the President at once. He said in present trend of public opinion a week could produce great changes. The reports of Casey confirm the view that the disposal of British Navy is the consideration which most profoundly weighs in the minds of the administration.
They have only recently realised Navy has been protecting the United States and Monroe Doctrine last hundred years. Consequently we should continue to emphasise the impossible position the United States would be in if she had to meet ultimately and alone a combination of German and Italian Fleets supplemented by remnants of British and French Navies on the one side, and the Japanese Navy on the other.
Therefore it is suggested that Lothian [6] be asked to put the views of the United Kingdom Government to the President, emphasising these pregnant possibilities, and reinforcing the recent appeal which we understand Churchill made on the question of supply of aircraft.
I suggest further, that Mackenzie King [7], who is I understand on very close and friendly terms with Roosevelt, might be asked if he would be prepared personally to visit the President with view to advancing vital necessity of early declaration or intervention by the United States.
You must not treat this cable as an indication that we have a defeatist point of view, quite the contrary, but we do feel that if action by America is to be sufficiently early to keep Italy out, to re-animate the French and to disturb the German civil population, the very strongest case based on America’s fears about her own position should be developed in the shortest possible time.
_
1 Documents 308 and 309.
2 Minister to the United States.
3 See Document 280.
4 See Document 300, note 4.
5 Document 319.
6 U.K. Ambassador to the United States.
7 Canadian Prime Minister.
_
[FA: A3196, 0.3420]