Memorandum by the Joint Chiefs of Staff to the Secretary of Defense (Marshall)2

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Subject: Strategic Importance of Formosa.

In accordance with the request contained in your memorandum, dated 20 December 1950,3 the Joint Chiefs of Staff have reviewed their previous estimates of the strategic importance of Formosa. In that regard it should be noted that prior to the outbreak of the Korean war, the Joint Chiefs of Staff position with respect to Formosa was that, although the island is strategically important to the United States, its importance did not justify overt military action.
The North Koreans invaded South Korea on 25 June 1950 and on 27 June 1950 the President of the United States directed the Commander-in-Chief, Far East, to repel any attack upon Formosa and the Pescadores and to stop attacks from Formosa upon the mainland.4 This directive is still in effect.
On 20 November 1950, the Joint Chiefs of Staff informed you [Page 1475] by memorandum5 that in their opinion the military neutralization of Formosa would not meet United States military strategic needs since it would:
Considerably improve the Communists’ strategic position and release some of their defense forces for build-up elsewhere; and
Substantially reduce our own strategic position in the area and would restrict freedom of action in the event the military situation requires that an armed attack against the Chinese Communists on the mainland be mounted.
The Joint Chiefs of Staff, in light of the undeclared war with Communist China, would like to reaffirm and amplify their position, as expressed on 20 November: The United States must retain complete freedom of action with respect to Formosa to the end that that island may be used by the United States or the Chinese Nationalists as a base for the conduct of offensive operations, including possible guerrilla action, against the Chinese mainland if such is required. Moreover, it must be recognized that Formosa is geographically a portion of the off-shore island chain and would be essential in the conduct of air and naval operations in the strategic defense of our off-shore island chain.
The Joint Chiefs of Staff would answer the specific questions posed by the Secretary of State in his memorandum to you, dated 4 December 1950, as follows:
  • a. Question: Would denial of Formosa as a base to the Chinese Communists meet the military strategic needs of the United States, insofar as these needs can be foreseen? If not, what are the additional United States strategic needs respecting the island?
  • Answer: The Joint Chiefs of Staff have no present intention of basing any United States forces on Formosa except as may become necessary to comply with the President’s directive of 27 June 1950. However, if a full scale war should develop against Communist China, or against the USSR with Communist China as a Soviet ally, it would be desirable to have port facilities and airfields on Formosa available to the United States.
  • We do not envisage an invasion of China by United States Troops even in the event of a full scale war. However, the Nationalist forces on Formosa constitute the only visible source of manpower for extensive guerrilla operations in China and a possible invasion of the mainland. Hence, until a solution is found for our major differences with Communist China, we should continue to safeguard Formosa.
  • b. Question: If these military needs cannot be met through diplomatic and economic measures, should the United States accept a commitment of its armed forces to insure that they are met?
  • Answer: The United States should be prepared, if its military needs on Formosa cannot be met through diplomatic and economic measures, to expand its employment of naval and air forces to safeguard Formosa. This would insure that the United States retains freedom of action for the utilization of Formosa as a base of operations for the Chinese Nationalist forces, as well as for possible future use of our own military forces. However no binding commitment should be made, since such a commitment might hamper sound military decisions in the future.
For the Joint Chiefs of Staff:
Omar N. Bradley

Joint Chiefs of Staff
  1. Secretary Marshall sent the memorandum to Secretary of State Acheson with a covering letter, dated January 3, not printed, stating that the Joint Chiefs of Staff had reviewed the strategic importance of Formosa in the light of the current situation in the Far East and in response to the questions in Acheson’s letter of December 4, 1950; for the text of the latter, see Foreign Relations, 1950, vol. vi, p. 587.
  2. Not printed.
  3. See the memorandum of conversation by Ambassador at Large Philip C. Jessup, June 26, 1950, and President Truman’s statement of June 27, 1950, Foreign Relations, 1950, vol. vii, pp. 178 and 202.
  4. Not printed, but see Acting Secretary of Defense Robert Lovett’s letter to Acheson, November 24, 1950, Foreign Relations, 1950, vol. vi, p. 579.