Washington, August 1, 1963.
DEAR BOB: We have given careful consideration to the points you raise in your letter of June 201McNamara's letter of June 20 to Rusk enclosed a JCS memorandum of May 23 (JCSM-387-63) and a JCS study entitled “Effect on Force Requirements of US Use of Nuclear Weapons at Outset of ChiCom Aggression Against Taiwan or Southeast Asia.” McNamara noted that the JCS conclusions included the argument that GRC forces should not be reduced because, among other considerations, they represented a strategic reserve “available for support of U.S. Objectives in the Far East” or “meeting contingency military requirements.” He requested Rusk's views on this and on a JCS proposal of January 1963 supporting the possible use of GRC forces up to three divisions in Southeast Asia. (Ibid., DEF 12 US) concerning certain aspects of the employment of GRC forces. We believe that GRC forces available as a strategic reserve of conventional force in the Far East would contribute to the support of U.S. objectives of deterring Chinese Communist aggression and under certain circumstances of countering such aggression if it should occur. At the same time we do not agree with the JCS recommendation that U.S. policy favor the principle of employment of GRC units in conflicts in Southeast Asia, though as will be noted subsequently there is one set of circumstances where such employment might be feasible.
It seems to me that we must be quite realistic in understanding that the Nationalist Government of China would not commit its military forces except as a part of a major engagement whose objective is the return of that Government to full control on the mainland of China. Conversely, the use of Nationalist Chinese forces in Southeast Asia, in the absence of Chinese Communist forces in that area, would almost inevitably result in the commitment of Chinese Communist forces to meet them. The Nationalist Chinese forces are of great importance to the United States in the event of a major Chinese Communist aggression, and I would think that we would wish to be very cautious about reducing those forces during the present period of uncertainty about Peiping's intentions following their break with Moscow. In evaluating the role of Chinese Nationalist forces, particularly ground forces, I also feel that we must assess their capabilities in the most rigorous professional manner and not be unduly influenced in this regard by mere hope or traditional goodwill.
With respect to the strategic reserve concept, from the Chinese Communist viewpoint, the existence of these GRC forces must be regarded as providing the United States and its allies with a number of options, all of which the Chinese Communists would have to take into account in planning aggressive action anywhere in Asia. The Joint Chiefs' study points out that the GRC forces keep large Communist forces tied down on the mainland opposite Taiwan. The forces so tied down would presumably be unavailable to support a major Chinese Communist aggression in Korea or in Southeast Asia. Moreover, given the presence of the GRC strategic reserve force on Taiwan, one can imagine that in the event of Chinese Communist aggressive action in Korea or Southeast Asia, GRC feints against various points along the mainland China coast might serve to draw Chinese Communist forces off from their main point of attack or at least to restrain the Chinese Communists from developing their attack to major proportions which would require U.S. employment of nuclear weapons.
However, the only situation in which, from a political point of view, we can clearly visualize the actual introduction of GRC troops in Southeast Asian countries (or in the territory of any other free Asian nation) would be in the case of large-scale Chinese Communist aggression, as such aggression is defined in the Chiefs' study. There are two reasons why, except in the case of large-scale Chinese Communist attack, it would be infeasible to introduce GRC forces into Southeast Asia. The first is that the countries concerned would be strongly opposed to the introduction of GRC forces. Second, the introduction of GRC forces would almost certainly provoke the introduction of Chinese Communist forces. Consequently, while we support the concept of a GRC strategic reserve, we would not support the establishment of a general policy of favoring the use of GRC forces in Southeast Asia.
Conceivably, GRC troops might be used to help meet a limited Chinese Communist action against Southeast Asian countries, but this seems undesirable. If the limited Chinese Communist attack were of a probing nature designed to test our reactions, or if the attack could be adequately met by conventional U.S. and other allied forces (SEATO and indigenous), GRC troops should not be introduced. The use of GRC troops could have an important effect on the Chinese Communist estimate of our intentions. If no GRC troops were brought in, the Chinese Communists might consider that our intention was only to stop their probe and drive the Communist forces back behind existing borders. If GRC divisions were brought in, even if initially in only limited numbers, the Chinese Communists might consider that the ultimate intention was to reinforce and thence to try to drive into mainland China. Peiping could believe that American forces would be used only to achieve limited objectives whereas they would be more likely to judge that GRC troops would participate only as a means of facilitating their return to power on the mainland. The Chinese Communists would go all out to meet what they regarded as a serious threat to their security. Consequently, the introduction of GRC divisions might transform what was initially intended only as a limited Chinese Communist probing action into a large-scale Chinese Communist aggression.
In all the spectrum of conflict which ranges below these upper levels of intensity, it clearly would be infeasible to use GRC troops in Southeast Asia. And, it is in the lower part of the spectrum—subversion, guerrilla warfare, clandestine introduction of North Vietnamese cadres and troops—that the principal Communist threat to Southeast Asia is manifested.
One point which ought to be noted in this consideration of GRC strategic reserve divisions is the attitude of the GRC itself toward the actual employment of these divisions. Chinese Nationalist interest in such employment would probably vary directly with the opportunity afforded them to confront the Chinese Communists. In any event, before the GRC would make available divisions of their better trained troops for use on the Asian mainland, they would weigh very carefully the effect of such action on their own security and aspirations.
Aside from these questions of the use of GRC forces, I was much interested in the Study's presentation of the pros and cons on the use of nuclear weapons at the outset of large-scale Chinese Communist aggression. It seemed to us that CINCPAC's views, as set forth in the study on pages 8 and 9,2The quotation of CINCPAC's views, which occurs in an annex to the study headed “Discussion,” reads: “I will not comment on the political aspects that militate against making such a critical assumption. However, from purely a military point of view, the resulting inflexibility evolving from such a concept is one which causes me great concern. Should such a concept result in a force incapable of conducting successful operations against ChiCom aggression without resort to the use of nuclear weapons, we would indeed have created conditions which would impose a degree of rigidity in our military forces which is undesirable and unwarranted.” were particularly pertinent. Politically and psychologically it will become even more important after a Chinese Communist nuclear detonation, to have adequate U.S. conventional capability in the Pacific so that free Asian nations will believe that we can assist in defending them against at least limited Chinese Communist attack without necessarily involving them in nuclear war.
I should appreciate being kept abreast of your consideration of these matters in order that there may be ample opportunity for mutual consultation about the development of our nuclear weapons policy in the Pacific area.
With warm regards,