178 Lord Cranborne, U.K. Secretary of State for Dominion Affairs, to Sir Geoffrey Whiskard, U.K. High Commissioner in Australia
Circular cablegram Z308 LONDON, 19 October 1940, 2.40 a.m.
My telegram of 15th October Circular Z.305.  In anticipation of discussions at Singapore with representatives of the United States and of the Netherlands, certain instructions had been prepared and sent to Commanders in Chief in the Far East as to line which should be taken in conversations. It has since been explained to Commanders in Chief that owing to later developments as to United States attitude conversations of wide scope envisaged in the instructions are not likely to take place in the immediate future and that instructions should accordingly be held in abeyance for the present.  In case however position should change and it is possible to conduct discussions at Singapore on this plane with United States and Dutch representatives, it may be of interest to the Prime Minister  to have the following summary of the instructions in question. BEGINS.
(a) Conversations to be conducted with complete frankness and full information on any questions raised to be imparted.
(b) Basic assumption that we, with the United States and the Dutch, are at war with Japan; decisions to be without prejudice or any political commitments.
(c) Object to co-ordinate plan for employment of British, United States and Dutch forces in the event of war with Japan.
(d) Discussions with United States to cover plans for common action in the event of Dutch failing to come in. Similarly discussions with Dutch to cover action in the event of the United States failing to come in.
(e) Scope to be limited to military problem in the Far East, Indian Ocean and Pacific, including Australia and New Zealand.
(f) Following to be covered:-
(1) Plans for strategical employment of Allied forces.
(2) Technical and administrative arrangements to enable Allied forces to operate together.
(g) United States representatives to be invited to take as basis for strategical discussions Far Eastern War Memorandum , United States fleet taking place of British naval forces in plan.
Principal question would be how far the United States would be able to make up our own naval deficit in plan and from where they would operate, i.e. Singapore, Hong Kong, Manila, Guam or Honolulu.
(h) As defence problem would include Philippines and Netherlands East Indies in addition to our own interests, Manila is thought most suitable as advanced main fleet base, provided that local defences are adequate. All British and Dutch bases to be considered available though Hong Kong might not in fact be practicable.
(i) Main offensive against Japan to be economic. With United States intervention patrols to cut Japanese trade with North America would be unnecessary.
(j) Primary role of Dutch naval forces to provide local defence in Netherlands East Indies, and to hold gateways into Indian Ocean in collaboration with other Allied forces.
(k) Under basic assumption set out above it is thought that possibility [of]  Japanese expedition against Australia or New Zealand can be ruled out, but danger of attempt on Hong Kong would remain.
(l) With United States battle fleet in the Far East likelihood of sea-borne attack on Malaya or Netherlands East Indies would be greatly reduced and communications with Indo-China subject to interruption. Nevertheless possibility of land and air attack on Malaya would remain.
(m) Far Eastern appreciation (summary in my telegram of 12th August Circular Z.24  amplified by tactical appreciation to be prepared at discussions at Singapore and modified by assumption of United States intervention, to be basis of discussions on local defence problems. ENDS.
(2) We have also had under preliminary consideration question of command in area in contingencies in question. It is felt that there would be advantage in the establishment of a unified [strategical] naval command in the Pacific Ocean and the Far East, including waters around the Netherlands East Indies, Malaya, Australia and New Zealand. Further it is thought that Britain [sic] and Dutch naval forces operating in the Far East and Pacific Ocean should be placed under United States command, with exception of purely local defence forces which would remain under local British and Dutch command. Any Dutch naval forces operating in purely local defence of Singapore should be under British command.
Indian Ocean would remain a British command under Commander-in- Chief East Indies, and we think United States and Dutch should place any naval forces operating to westward of Dutch islands under our operational command.
(3) The foregoing suggestion as to United States command of the naval forces in the Far East and the Pacific is intended to apply to Australian and New Zealand naval forces as well as our own and is therefore subject to concurrence of His Majesty's Governments in those Dominions.
(4) No question of command of land forces would, it is thought, be likely to arise with United States or Dutch. As regards air units operating from Allied territory other than their own our view is that these should come under operational control of air command in which they are operating.
(5) Instructions to our representatives at the London discussions are similar to those set out above but are somewhat more detailed especially as regards United States air and army co-operation.
Relevant problems of economic warfare will also be discussed in London in collaboration with the Ministry of Economic Warfare, including ability of the United States to exercise control at source in South America and Dutch plans for denial to Japan of oil from the Netherlands East Indies.
(6) Please inform the Prime Minister as above for his most secret and personal information.