280 Mr R. G. Menzies, Prime Minister, to Mr R. G. Casey, Minister to the United States
Cablegram unnumbered 26 May 1940,
MOST SECRET IMMEDIATE
I shall be glad if you will arrange for the immediate personal presentation to President Roosevelt on behalf of myself of the following message - 'In this hour of great emergency, not only for Great Britain and for France, but also for Australia and the other British Dominions, I desire to put before you certain considerations.
Though we are determined to win and are by no means anticipating defeat, it is still obviously possible that France may be defeated and that in such an event Great Britain's power to resist Germany will depend on her Navy and her ability to resist or prevent air attack.
This would mean that air strength would become vital, and I do not need to point out to you that Germany has great numerical preponderance. Successful attacks upon British factories interrupting production might be decisive.
I hope you will not find me unduly unconventional if I say to you, as the head of the greatest but most friendly neutral power, that the prevention of British Fleet falling into German hands in consequence of a defeat of Great Britain must be of vital importance to the United States.
I cannot believe that the United States can view with anything but acute anxiety a Europe completely dominated by Germany and a victorious Germany exercising undisputed power in the Eastern Atlantic and its adjoining seas. One must also remember that on a defeat of Great Britain the handing over of the West Indian islands would undoubtedly be demanded by Germany.
I believe that your great country has it in its power to make a decisive contribution without itself actually participating. The one country that can rapidly and substantially increase British air power is the United States and even if this means despatch to Great Britain of machines already in commission or designed for your own Air Force I would most earnestly urge you to follow that course.
I am quite confident of the British capacity to meet all attacks against the United Kingdom and in turn to inflict such damage upon Germany as to produce her defeat-provided that the United States can supply the additional aeroplanes which are required. But quite plainly-and I know that you would wish me to speak plainly-without the most prompt material assistance from the United States there must be a grave danger of a state of affairs rapidly developing in which the power of Great Britain to defend liberty and free institutions is destroyed and in which we, your English-speaking neighbours on the Pacific Basin, must find our own independence immediately imperilled.
There is in Australia a great belief in your friendliness and goodwill. We feel that we are fighting for immortal things which you value as we do.
On behalf of my own people I beg for your earnest consideration and swift action. 
R. G. MENZIES