At the second Cairo Conference between the Prime Minister and the President , held after their return from the meeting with Stalin at Teheran , the war against Japan was exhaustively considered and the broad strategic concept was laid down. The discussions at this Conference have greatly advanced thought on the problem of how the full weight of the United Nations can be projected against Japan after Germany is defeated.
The Dominions Office will probably be telegraphing you in the near future an outline of what is described as the over-all plan for the defeat of Japan.  I will not anticipate what will be contained in this telegram beyond giving you a broad outline of the basis of the plan. It visualises that Germany may be defeated as early as the Spring of 1944; that the U.S.S.R. may enter the war against Japan soon after the defeat of Germany and that the defeat of Japan may be accomplished by sea and air blockade and intensive air bombardments from progressively advanced bases. The main concept of the plan is that the principal effort against Japan should be made in the Pacific and that operations in other theatres, e.g. China and South East Asia, would be complementary but subsidiary. It is visualised however that with Russia's entry into the war developments in the Northern Pacific would probably assume major importance. The main line of advance contemplated is on the New Guinea-Netherlands East Indies-Philippine axis with concurrent operations against the Mandated Islands.
A Naval Mission is leaving for Washington at an early date to concert plans for the utilisation of British Naval Forces in the Indian Ocean and Pacific including the South-West Pacific and the Combined Chiefs of Staff have now under consideration the question of the land and air forces that can be made available and utilised against Japan. These plans include the sending of four United Kingdom Divisions to Australia.
General Sutherland has, I understand, taken to Australia for General MacArthur the documents covering the decisions reached at Sextant and you will probably be receiving Dominions Office telegram referred to above in the near future.
Until you receive this telegram please treat above as most secret and for your personal information.