Appendix H
Conduct of the War in the Pacific Theater in 1943, Memorandum by U.S. Joint Chiefs of Staff, 22 January 1943 (CCS 168)
1. Japan has expanded the scope of her occupation so that it includes not only her former holdings of (1) Korea and Manchuria on the mainland of Asia and (2) a considerable part of China (including all of the coast) , but in the past year, (3) all of Indo-China, Malaysia, Thailand, most of Burma, and as well, (4) all of the Philippines and (5) the Dutch East Indies.
2. The ultimate defeat of Japan proper will be accomplished by measures which greatly resemble those which would be effective against the British Isles—blockade (attack on ships and shipping) , bombing (attack on forces, defenses, industries, and morale) , and assault (attack via the sea.) Of these measures, attacks on ships and shipping along enemy lines of communications are inherent in all offensive operations; it is our purpose during 1943 to work toward positions from which Japan can be attacked by land based air; assault on Japan is remote and may well not be found necessary. Allied offensive measures in 1943 comprise continued and intensified attacks on enemy ships and shipping, in the cutting or threatening to cut enemy lines of communication between Japan and Japanese holdings, and in attacks on enemy sea, air, and ground forces by obliging them to fight to retain their holdings and to maintain their lines of communication.
3. The scope and intensity of the Allied war effort in the Pacific during 1943, while conditioned on the premise that Germany is the principal enemy, requires that sufficient means be in hand surely to counter enemy potentialities (para. 4 to follow) and, further, must take care that the means in hand are actively employed to best advantage. The general capabilities of the Allied effort in the Pacific in 1943 comprise:
(a) Keep Japan from further expansion, and from consolidating and exploiting her current holdings.
(b) Maintain the vital Midway-Hawaii line (key to the Pacific) .
(c) Secure the line of communications to Australia and New Zealand.
(d) Block enemy approaches to Australia (1) from the Northward via Rabaul (2) from the Northwestward via the Malay barrier.
(e) Attain positions which menace enemy line of communication with the Dutch East Indies, the Philippines, and the South China Sea.
(f) Open the line of communications with China via Burma—in order to make use of Chinese geographical position (as to attack enemy line of communication in Formosa Straits and along the coast of China, perhaps to bomb Japan) .
(g) Make ready to support Russia in case of war with Japan.
(h) Continue and intensify attrition of enemy strength by land, air, and sea (including submarine) action.
4. Japan’s potentialities for offensive action during 1943 embrace:
(a) the Maritime Provinces (Eastern Siberia) –Russia;
(b) Alaska via the Aleutians;
(c) the Midway-Hawaii line—key to the Pacific
(d) the Hawaii–Samoa–Fiji–New Caledonia line, which covers the line of communications to Australia and New Zealand;
(e) Australia and New Zealand—via the Bismark Archipelago and/or the Solomons;
(f) Australia—via the Malay barrier;
(g) India—via Burma;
(h) China;
(i) Of the above, (a) is static unless and until war takes place between Russia and Japan; (b) has proved, and will continue, unprofitable to Japan; (c) has been tried and may be tried again but is unlikely to succeed; (d) is now unprofitable except via the Gilbert and Ellice Islands toward Samoa (the Jaluit-Samoa line) ; (e) is now under contest by United Nations forces; (f) is unprofitable except to forestall Allied advance from N.W. Australia; (g) is feasible except that enemy position is already well extended; (h) same as (g)—profitable chiefly to forestall Allied action.
5. Allied seizure and occupation, now in progress, of the New Caledonia/New Guinea line has for objectives:
(a) security of the line of communications from U.S. to Australia and New Zealand;
(b) blocking of enemy approaches to Eastern Australia;
(c) points d’appui for further action;
(d) attrition of enemy forces which oppose our occupation.
6. Additional to the objectives attained by the seizure and occupation of the New Caledonia/New Guinea line (para. 5 above) , the other feasible objectives for us appear to be:
(a) Japan via the Maritime Provinces (Eastern Siberia) noted only for record to offset 4 (a) above.
(b) Japan via the Aleutians and Kuriles—from Alaska.
(c) Advance from Midway towards Truk-Guam line via Wake and Northwesterly Marshall Islands.
(d) Advance on the Samoa-Jaluit line via Ellice and Gilbert Islands.
(e) Advance from Rabaul area on Truk-Guam line.
(f) Dutch East Indies via Malay barrier (as Timor).
(g) participation in ANAKIM.
(h) Of the above (which are set down to match the items of para. 4 above) :
(a) is merely potential unless and until war takes place between Japan and Russia;
(b) is unprofitable with means in sight in 1943 and is best undertaken, if at all, in connection with (a) ;
(c) is most useful, not only as to
(1) retention of initiative;
(2) partial counter to enemy potentialities of para. 4 (c) ; and, particularly,
(3) to draw off enemy forces involved in holding Rabaul area;
(d) is effective
(1) to forestall enemy potentialities in para. 4 (d) ;
(2) to make the line of communications to Australia and New Zealand fully secure; and
(3) to draw off enemy forces involved in Rabaul area;
(e) cannot be done until after consolidation of the Rabaul area upon completion of operations now in hand—see para. 5 above—but should, perhaps must, eventually be undertaken;
(f) useful on limited scale
(1) to counter enemy potentialities of par. 4 (f) ;
(2) to draw off enemy forces elsewhere in the Pacific;
(3) to employ forces available in Australia (after completion of para. 5) which would not otherwise be employable; N.B.—Attacks are not to be developed fully, as this might lead to extensive operations of the nature of frontal attacks.
(g) not effective before November though forces contributed would likely have to be made available in October—but—ANAKIM is of such importance in respect of its objective (bringing Chinese manpower and geographic position to bear on Japanese forces and positions) as to merit that priority which may be found indispensable to mount it.
7. Referring now to the general capabilities of Allied action listed in para. 3 above, set off against enemy potentialities in para. 4 above, we intend, as to the feasible objectives of par. 6 above—additional to those of par. 5 above—to:
(a) and (b)—make the Aleutians as secure as may be—which will implement 3 (a) (g) (h) ; N.B.—Germany can be expected to intensify pressure on Japan to attack Russia in Siberia (Maritime Provinces) .
© undertake advance from Midway towards Truk-Guam line as practicable—to implement 3 (a) (b) (e) (h) and, particularly, when 6 (e) is undertaken;
(d) undertake advance along Samoa-Jaluit line to implement 3 (a) (c) (h) ;
(e) refrain from advance from Rabaul area towards Truk-Guam line unless and until forces are in hand to enable it to be carried through and followed up. Noted that it implements 3 (a) , (b) , (d) (i) , (e) , (h) ;
(f) undertake advance on the Malay barrier (as Timor) on limited scale to counter enemy capabilities and divert his forces—to implement 3 (a) , (d) (2) , (e) , (h)
(g) participate in ANAKIM as may be found indispensable to mounting it.