Foreign Relations of the United States, 1958–1960, China, Volume XIX

47. Special National Intelligence Estimate⁰

SNIE 100–9–58

Washington, August 26, 1958.

PROBABLE DEVELOPMENTS IN THE TAIWAN STRAIT AREA

The Problem

To estimate probable developments in the Taiwan Strait area over the next few months, with particular reference to (a) Chinese Communist capabilities, (b) Chinese Communist courses of action, (c) Chinese Nationalist courses of action, and (d) Chinese Communist reactions to Chinese Nationalist and/or US measures to maintain control of the Nationalist-held offshore islands.

Conclusions

1. We believe that Communist China’s principal purpose in stepping up its military pressures in the Taiwan Strait area is to test the intentions of the US and of the Republic of China (GRC) with respect to the offshore islands. Communist China probably expects that the resultant increase in tensions will also increase pressures for its participation in world decisions, arrest any drift toward acceptance of a de facto “two Chinas” situation, and, especially if the US should seem reluctant to take strong measures to hold the offshore islands, accelerate the erosion of Nationalist morale, [less than 1 line of 2-column source text not declassified]

2. In view of US commitments to defend Taiwan and our estimate that neither Communist China nor the USSR is willing to risk a major war at present, we believe that Communist China will not attempt to seize Taiwan or the Penghus during the next six months at least, [less than 1 line of 2-column source text not declassified]

3. Although Communist China might risk a sudden assault upon the major offshore islands, we believe it more likely that it will not attempt to do so in the immediate future, because of its fear of possible US intervention. Communist China will probably continue to exert military pressures against the Chin-men (Quemoy) and Matsu groups, seeking to avoid a clear point of military showdown. Depending on US reactions, these pressures could include intensive and sustained artillery harassment of Chin-men (Quemoy), aggressive air and naval action in the Strait area, provocative overflights of Taiwan, seizure of lightly-defended offshore islands, and a serious effort to interdict supply of the Chin-mens and Matsus. If US reactions to these pressures should lead the Chinese Communists to believe that the US would not intervene, they would probably then attempt to seize Chin-men or Matsu, or both, [less than 1 line of 2-column source text not declassified]

4. If opposed only by Chinese Nationalist forces, the Chinese Communists have the capability to deny the Taiwan Strait to the Chinese Nationalist air force, interdict supply of the offshore islands, or seize these islands. Timely warning might not be available that preparations had been completed for an assault on either the Chin-men or the Matsu groups, [less than 1 line of 2-column source text not declassified]

5. We believe that the Chinese Communists will not be deterred from increasing their military pressures by US moves which stop short of either an explicit guarantee of the offshore islands or the commitment of US air or naval forces at least to the protection of the supply of these islands. However, if the US gave an explicit guarantee or committed its forces to the defense of the major offshore islands, the Chinese Communists would probably not attempt to seize those islands or interdict their supply, [less than 1 line of 2-column source text not declassified]

6. Nevertheless, Communist China’s activation of its coastal airfields and aggressive attempts to deny its airspace to overflights are probably here to stay, regardless of Chinese Nationalist and US actions. To a somewhat lesser degree, so are Chinese Communist air sorties and other probing actions in the Taiwan Strait area, [less than 1 line of 2-column source text not declassified]

7. The Chinese Nationalists will probably not resort to unilateral action against the mainland so long as Chinese Communist pressures stop short of a heavy and sustained air or artillery bombardment of the offshore islands, or a determined effort to interdict supply of Chin-men or Matsu. Should the Chinese Communists take such steps, the chances are better than even that the Nationalists would take whatever military action they could against the mainland. They might then bomb mainland targets, even in the face of explicit US objections, [less than 1 line of 2-column source text not declassified]

[Here follow 11-1/2 pages of source text scheduled for inclusion in the Supplement, but not declassified, comprising the “Discussion” portion of the estimate, with an introduction and estimates of Chinese Communist capabilities and intentions, Chinese Nationalist courses of action, and Chinese Communist reactions to Chinese Nationalist and/or U.S. measures to maintain control of the offshore islands, [text not declassified].]

0. Source: Department of State, INR–NIE Files. Secret. A note on the cover sheet reads in part as follows:

   “Submitted by the Director of Central Intelligence.

   “The following intelligence organizations participated in the preparation of this estimate: The Central Intelligence Agency and the intelligence organizations of the Departments of State, the Army, the Navy, the Air Force, and The Joint Staff.

   “Concurred in by the Intelligence Advisory Committee on 26 August 1958.”