S/SNSC files, lot 63 D 351, NSC 147 Series

Memorandum by the Deputy Assistant Secretary of State for Far Eastern Affairs (Johnson) to the Secretary of State1

top secret


  • Analysis of Possible Courses of Action in Korea—NSC 147.


The NSC Planning Board has prepared for Council decision on April 8 a long analysis of possible courses of action in Korea.2 If the armistice negotiations fail, there appear to be two major alternative courses [Page 881] of action open to the United States in Korea short of initiation of global war by the United States. The first alternative would be to continue or expand military action only within Korea; while the second alternative would remove existing restrictions on military operations against Communist China and Manchuria. NSC 147 analyzes three possible specific courses of military action under each alternative, making a total of six specific courses of action presented in the order of increasing severity, and defined on pages 1–3 of NSC 147.

NSC 147 analyzes but does not recommend a choice of either alternative or any specific course of action under these alternatives. A long estimate of the JCS of March 30 [27], 19533 also analyzes but does not recommend any particular course of action in Korea. NSC 147 does not take into consideration events subsequent to the recent Communist offer to exchange sick and wounded and the Chou En-lai proposal for resuming armistice negotiations.

It is desirable that on April 8 the Council decide on a military course of action for implementation if it later develops that the Communists are not acting in good faith with respect to their recent proposals.

Alternative II, authorizing military actions against Communist China and Manchuria, would create most serious political difficulties. If the United States should propose that United Nations forces in Korea initiate any one of the courses of action under Alternative II, our principal allies would immediately resist such a decision and some of them might withdraw their forces and support from the United Nations operations in Korea. Such a United States decision would put severe strains in the western alliance and would alienate much pro-United States feeling in free Asia. However, if the Communists should launch a large scale ground offensive in Korea or large scale air attacks, our principal allies would probably support retaliatory air action against Manchuria and Communist China. The Government of the Republic of Korea would prefer Alternative II and wider military actions in and near Korea if they were the only means to unify Korea.

Regardless of the intent of the United States, it must be recognized that all of the alternatives under Course II in themselves involve varying degrees of increased risk of global war as compared with any of the alternatives under Course I. This risk is, of course, increased to the degree that any of the alternatives under Course II divides the United States from its allies and leads the Soviets to the assumption that Soviet military action against the United States or its forces could be undertaken with the Allies divided from the United States. Therefore, apart from the increased military requirements for use in the Korean hostilities, it is most seriously to be questioned whether the United States should bring about a situation involving such increased risks of general [Page 882] war without at the same time increasing its ability to cope with such a war by markedly broadening and stepping up its entire mobilization base. Because of the terms of reference under which the Planning Board was drafting this analysis and the exigencies of the time available, the foregoing factors are not fully reflected in the analysis. It is, therefore, suggested that any final decision by the NSC to adopt one of the courses of action under Alternative II should be deferred pending an immediate study of all of its implications.

Alternative I, of course, presents fewer political problems than Alternative II. If that alternative is adopted, the question is to decide among the three courses set forth therein. From a political point of view, it would be desirable to undertake a course of action which would have the greatest immediate effects without risking major hostilities outside Korea. Course C probably best meets this test. If successful, it would enhance the prestige of the United Nations and the United States in the Far East, reduce Chinese Communist capabilities, and bring all of the most significant area of Korea under the control of the United Nations. While our allies would not propose this course of action, it is believed that with sufficient persuasion they would come to accept it, if there were no hope of concluding a successful armistice. It should be pointed out that Course C will take several months for military preparations and that it would be conducted under certain serious military disadvantages (Paragraphs 101–108).4


It is recommended that you:

Favor Course C of Alternative I; and
Propose the Council recommend to the President that:
He authorize initiation of Course C Alternative I in sixty days if by that time the NSC advises him that there appears to be no reasonable anticipation that an armistice can be successfully and quickly concluded, and
The Department and agencies concerned now begin the necessary preparation within the United States Government to put Course C into effect upon the receipt of Presidential authorization. (This must, of course, include necessary budgetary preparations.)

  1. This memorandum was drafted by Young and cleared with Matthews.
  2. NSC 147; for excerpts, see p. 839.
  3. The reference was to an attachment to NSC 147 which is not printed.
  4. In paragraphs 101 to 108, which are not printed in the excerpted portion of the Staff Study attached to NSC 147, p. 841, the following military disadvantages of a major offensive to the waist of Korea were cited: 1) “Highly unpalatable personnel costs” unless restrictions upon military operations against China and Manchuria were lifted; 2) the possible necessity for attacks against Communist air forces and use of atomic weapons to ensure ultimate success; 3) high ground casualties because of strong Communist defenses; 4) a UN build-up to counter the Communist capability of reinforcing Korea with 35 divisions; 5) longer UN lines of communication; 6) the difficulty of defending the waist of Korea, thus necessitating plans to carry the war to the Yalu if a military victory short of that line could not be achieved; 7) the general military threat of China in the Far East outside of Korea; and 8) the adverse effect on the ability of U.S. armed forces to support emergency war plans.