64 Lord Caldecote, U.K. Secretary of State for Dominion Affairs, to Sir Geoffrey Whiskard, U.K. High Commissioner in Australia
Cablegram 262 LONDON, 11 August 1940, 6.48 p.m.
IMMEDIATE PERSONAL AND MOST SECRET
Please communicate to the Prime Minister  the following personal and most secret message from the Prime Minister.  (Begins).
The combined staffs are preparing a paper on the Pacific situation but I venture to send you in advance a brief foreword. We are trying our best to avoid war with Japan both by conceding on points where Japanese military clique can perhaps force a rupture and by standing up where ground is less dangerous as in arrests of individuals. I do not think myself that Japan will declare war unless Germany can make a successful invasion of Britain. Once Japan sees that Germany has either failed or dares not try I look for easier times in the Pacific. In adopting against the grain a yielding policy towards Japanese threat we have always in mind your interests and safety.
2. Should Japan nevertheless declare war on us her first objective outside the Yellow Sea would probably be the Dutch East Indies.
Evidently the United States would not like this. What they would do we cannot tell. They give no undertaking of support but their main Fleet in the Pacific must be a grave preoccupation to the Japanese Admiralty. In this first phase of an Anglo-Japanese war we should of course defend Singapore which if attacked, which is unlikely, ought to stand a long seige. We should also be able to base on Ceylon a battle cruiser and a fast aircraft carrier which with Australian and New Zealand ships which would return to you would exercise a very powerful deterrent upon hostile raiding cruisers.
3. We are about to reinforce with more first-class units the Eastern Mediterranean Fleet. This Fleet could of course at any time be sent through the Canal into the Indian Ocean or to relieve Singapore. We do not want to do this even if Japan declares war until it is found to be vital to your safety. Such a transference would entail complete loss of Middle East and all prospects of beating the Italians in the Mediterranean would be gone. We must expect heavy attacks on Egypt in the near future and the Eastern Mediterranean Fleet is needed to help in repelling them. If these attacks succeed the Eastern Fleet would have to leave the Mediterranean either through the Canal or by Gibraltar. In either case a large part of it would be available for your protection. We hope however to maintain ourselves in Egypt and to keep the Eastern Fleet at Alexandria during the first phase of an Anglo- Japanese war should that occur. No one can lay down beforehand what is going to happen. We must first weigh events from day to day and use our available resources to the utmost.
4. A final question arises whether Japan having declared war would attempt to invade Australia or New Zealand with a considerable army. We think this very unlikely because Japan is first absorbed in China secondly would be gathering rich prizes in the Dutch East Indies and thirdly would fear very much to send an important part of her Fleet far to the southward leaving American Fleet between it and home. If however contrary to prudence and self-interest Japan set about invading Australia or New Zealand on a large scale I have explicit authority of Cabinet to assure you that we should then cut our losses in the Mediterranean and proceed to your aid sacrificing every interest except only defence position of this island on which all depends.
5. We hope however that events will take a different turn. By gaining time with Japan the present dangerous situation may be got over. We are vastly stronger here at home than when I cabled to you on 16th June.  We have a large army now beginning to be well-equipped. We have fortified our beaches. We have a strong reserve of mobile troops including our regular army and Australian, New Zealand and Canadian contingents with several armoured divisions or brigades ready to strike in counter attack at head of any successful lodgments. We have ferried over from the United States their grand aid of nearly one thousand guns, six hundred thousand rifles with ammunition complete. Relieved of the burden of defending France our army is becoming daily more powerful and munitions are gathering. Besides this we have a home guard of 1,500,000 men many of them war veterans and most with rifle or other arms.
6. The R.A.F. continue to show the same individual superiority over the enemy on which I counted so much in my aforesaid cable to you. Thursday's important air action in the Channel showed that we could attack against odds of three to one and inflict losses of three and a half to one.
Astounding progress has been made by Lord Beaverbrook  in output of best machines. Our fighter and bomber strength is nearly double what it was when I cabled you and we have a very large reserve of machines in hand. I do not think that the German Air Force has the numbers or quality to overpower our air defences.
7. The Navy increases in strength each month and we are now beginning to receive immense programme started at the declaration of war. Between June and December 1940 over 500 vessels large and small but many most important will join the Fleet. The German Navy is weaker than it has ever been. Scharnhorst and Gneisenau are both in dock damaged. Bismarck has not yet done her trials.
Tirpitz is three months behind Bismarck. There are available now in this critical fortnight after which time invasion is getting very late one pocket-battleship, a couple of 8 inch Hipper, two light cruisers, perhaps a score of destroyers. To try to transport large army as would now be needed for success across seas virtually without naval escort in face of our navy and air force only to meet our powerful military force on shore still less to maintain such an army and its lodgments with munitions and supplies would be a very unreasonable act. On the other hand if Hitler fails to invade and conquer Britain before the weather breaks he has received his first and probably his fatal check.
8. We therefore feel a sober and growing conviction of our power to persevere through the year or two that may be necessary to gain victory. Ends.