Foreign Relations of the United States, 1950, Korea, Volume VII

795.00/11–950

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

top secret

Washington, 9 November 1950.

Subject: Chinese Communist Intervention in Korea

1. In accordance with the request contained in your memorandum, dated 6 November 1950,¹ the Joint Chiefs of Staff have formulated the following views on the military significance of Chinese Communist intervention in North Korea.

2. It has been suggested that the Chinese Communist forces intervening in North Korea might be composed of “volunteers.” The objective of such an intervention, if this view were accepted, might be the interposing of sufficient Chinese Communist men and equipment in the paths of the advancing United Nations forces in order to delay them and to gain time for the defeated and disorganized remnants of the North Korean Army. The delay thus imposed on the United Nations forces might enable the North Koreans to make preparations for protracted guerrilla warfare in Korea and possibly to attempt to hold during the winter months the entire north central mountain region near the Yalu River. Intelligence reports indicate, however, that Chinese Communists are entering North Korea both as individuals and as well-organized, well-led and well-equipped Chinese Communist units, probably as large as divisions.

3. Chinese Communist intervention in Korea must have been motivated either by pressure of the USSR or by genuine Chinese reasons or by a combination of both. There is no conclusive evidence at hand upon which to draw sound inferences as to what governs. However, regardless of the motives involved, any one or combination of the following objectives is logical:

a. To protect the Yalu River and the Changjin-Pusan reservoir power complex and possibly to establish a cordon sanitaire in North Korea;

b. To continue the active undeclared war in Korea; and

c. To drive the United Nations forces from Korea.

4. Protection of the Yalu River and the Changjin-Pusan reservoir power complex and possibly the establishment of a cordon sanitaire in North Korea:

a. The Chinese Communists might fear that if the United Nations forces capture the Changjin-Pusan power complex they would either destroy or damage these facilities, or divert to Korea power now being received by the Chinese. It is understood that the electricity generated by these power systems furnishes light and power to Manchuria, including Mukden, Port Arthur, and Dairen and that the distribution systems are on the North Korean side of the Yalu River. If the Chinese Communists were prevented from obtaining electricity from these power system it would be a severe economic blow to Manchuria;

b. If the Chinese Communists are attempting to protect the Yalu River and the power systems in North Korea, it would be to their advantage to establish the defenses at some distance from the river and the power systems, and to hold a buffer border zone in North Korea. In any event, to accomplish this objective it would be necessary to hold the central mountainous region of North Korea and thus flank the coastal approaches to the Manchurian border;

c. If the Chinese Communists have intervened in North Korea solely for this purpose, their withdrawal might be accomplished by an unmistakably clear announcement of a guarantee by the United Nations that:

(1) The United Nations forces would not infringe on the sovereignty of Manchuria;

(2) The dams, power plants, and electric distribution systems would not be damaged or interfered with; and

(3) The present distribution of electricity from the power plants would not be changed except by mutual arrangements of the contracting parties.

d. Such an announcement and guarantee, if made, would in any event clarify the situation, since if the Chinese Communists refused to accept the guarantee, this possible objective would be eliminated from further consideration.

5. Maintenance of an active undeclared war in Korea:

a. The Chinese Communists might place sufficient forces in Korea in order to continue the undeclared war in Korea and thus force the United Nations and particularly the United States to retain its armed forces now there merely to maintain the present positions;

b. Korea is at such a distance from the United States that it would be expensive for the United States in manpower, materials, and money to conduct an undeclared war in that area over a long period. Conversely, China is adjacent to Korea and it would be comparatively inexpensive for the Chinese Communists, with their practically unlimited manpower and with Soviet equipment, to carry on such a war indefinitely. The continued involvement of the United States forces in Korea would be in the interests of the USSR and of world communism by imposing a heavy drain on United States military and economic strengths;

c. It would also be in the interests of the USSR for the meager military forces in being of the United States to be committed in a strategically unimportant area. From the viewpoint of a global war, the United States would thus be off balance while the USSR perfects and completes its plans for global conquest and prepares to deliver a surprise blow;

d. The intervention in Korea would jeopardize the security of the United States if the undeclared war were to be permitted to sap our strength and leave us unprepared for Soviet attack elsewhere. The United States might, under such circumstances, win the skirmish in Korea but lose the war against the USSR if global war eventuates.

e. An undeclared war in Korea between Chinese Communist intervention forces and United Nations forces, if localized, would offer the possibility of settling the conflict by negotiation during the conduct of which South Korean military forces could be materially increased. Additionally, the time thus gained could be utilized for a further build-up of the industrial potential and the military strength of the United States.

6. Driving United Nations forces out of Korea:

The Chinese Communists might intend to commit enough forces to drive the United Nations forces out of Korea. However, it is doubtful if this could be accomplished without material assistance by Soviet naval and air power. In this event it would be evident that World War III was upon us and the United Nations forces should be withdrawn from Korea as expeditiously as possible.

7. As to military eventualities in other areas, the Chinese Communists can be expected to recognize the increased drain on the military resources of the nations of the Western world which will result from their intervention in Korea, and to assume that there would be a corresponding lessening of the military capabilities of those nations. Therefore, it is possible that if Chinese intervention in Korea is of limited nature it may well be accompanied by Communist aggression in other countries, such as by attempting the invasion of Formosa, by taking Hongkong and Macao, by intervening more actively in Indochina, by invading Burma, or by occupying Tibet.

8. Chinese Communist air units are operating in Korea from nearby bases in Manchuria; they are thus taking advantage of the present technical inviolability of Manchuria to use it as a sanctuary. Similarly, their army units are able to move from the Manchurian sanctuary to the fighting lines overnight. Such a situation may well become intolerable. Although to a certain extent dependent on the relative scale of effort maintained by the Chinese Communists, there appears strong likelihood that the tactical situation in Korea will demand that the United Nations commander “be authorized to take appropriate air and naval action outside Korea against Communist China,” as provided in NSC 73/4² and NSC 81/1.³

9. Also depending on the relative scale of efforts on the part of the Chinese Communists, there are three courses of action open to the United Nations forces: (a) force the action to a successful conclusion in Korea; (b) continue the action on a defensive line short of the Korean border; or (c) withdraw. The first course may require some augmentation of military strength in Korea even if the Chinese Communist scale of effort is not materially increased. The second course is apparently feasible now and it might be a temporary expedient pending clarification of the military and political problems raised by Chinese intervention which are as yet unanswered. The third course, withdrawal, if conducted voluntarily would so lower the worldwide prestige of the United States that it would be totally unacceptable, and if conducted involuntarily could only be accepted as the prelude to global war.

10. The fact of military intervention by the Chinese Communists does not of itself provide conclusive indication that the USSR intends to launch a global war at this time. On the other hand, the United States should “recognize the increased strain on the fabric of world peace” arising from such intervention. The present situation brings to a sharp focus the statement appearing in NSC 73/4:

“Global war could come in one of three ways: (a) Soviet design; (b) by a progression of developments growing out of the present situation; or (c) by a miscalculation on the part of either the United States or the USSR.”

Even though the United States makes every effort to localize the present conflict, a review of its probable eventualities leads to the conclusion that there now exists a greatly increased risk of global war.

11. In summary, the Joint Chiefs of Staff are of the opinion that the following implications of military significance with respect to the Chinese Communist intervention in North Korea may be drawn:

a. The Chinese Communists are presently in Korea in such strength and in a sufficiently organized manner as to indicate that unless withdrawn they can be defeated only by a determined military operation.

b. The military objectives of the Chinese Communist intervention in Korea are not yet clear.

c. A sustained military campaign in Korea would serve as a heavy drain on our military potentialities.

d. From the military standpoint, the continued commitment of U.S. forces in Korea is at the expense of the more useful strategic deployment of those forces elsewhere.

e. It is not envisaged that the Chinese Communists and the North Koreans could drive presently committed United Nations forces from Korea unless materially assisted by Soviet naval and air power. In the event of the commitment of the latter, U.S. forces should be withdrawn from Korea as it would then be evident that World War III is imminent.

f. Under present restrictions the Chinese Communists are permitted to use Manchuria as a hostile sanctuary for aircraft directed against the United Nations forces.

g. There appear to be three general courses of action open to United Nations forces:

(1) Force the action to a successful conclusion in Korea.

(2) Establish and maintain a defensive position on a line short of the Korean border.

(3) Withdrawal.

h. The present conditions do not indicate conclusive evidence that global war is imminent but rather that the risk of global war is increased.

12. Therefore, the Joint Chiefs of Staff conclude that:

a. Every effort should be expended as a matter of urgency to settle the problem of Chinese Communist intervention in Korea by political means, preferably through the United Nations, to include reassurances to the Chinese Communists with respect to our intent, direct negotiations through our Allies and the Interim Committee with the Chinese Communist Government, and by any other available means.

b. Pending further clarification as to the military objectives of the Chinese Communists and the extent of their intended commitments, the missions assigned to the Commander in Chief, United Nations Command should be kept under review, but should not be changed.

c. The United States should develop its plans and make its preparations on the basis that the risk of global war is increased.⁴

For the Joint Chiefs of Staff:

Omar N. Bradley

Chairman
Joint Chiefs of Staff

1. Not printed.
2. Text and related documentation are scheduled for publication in volume i.
3. Of September 9, p. 712.
4. Paragraphs 11 and 12 of the above memorandum were read as the views of the JCS at the 71st meeting of the National Security Council on November 9; for an account of that meeting, see Truman, Years of Trial and Hope, pp. 378–380.