111. Special National Intelligence Estimate1

SNIE 10–3–65

McGeorge Bundy forwarded SNIE 10–3–65 and SNIE 10–3/1–65 (Document 139) to President Johnson on February 19 under cover of a memorandum stating that both estimates “are important enough for you to read in full” and “seem careful and sober to me” and “suggest the wisdom of your determination to act in a measured and fitting way.” (Johnson Library, Memos to the President, McGeorge Bundy, Vol. VIII)


The Problem

To estimate Communist reactions, particularly Soviet reactions, to a US course of sustained air attacks on North Vietnam.

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Scope Note

This US course is presumed to start with a public declaration outlining the new policy and linking it to the entire range of Viet Cong guerrilla and terrorist activity in South Vietnam. This declaration, we further presume, makes it clear that the US means to go beyond specific reprisals for individual major Viet Cong actions and to continue air attacks until the threat to South Vietnam has been reduced to levels which the US regards as tolerable. We consider in this estimate present Communist attitudes and Communist reactions, particularly Soviet reactions, in the period before and during continuing air attacks, and during any period when these attacks are suspended.

The Estimate

The Present Situation

1. Reversing Khrushchev’s policy of minimum involvement in Southeast Asia, the new Soviet leaders have over the past several months begun to reassert the USSR’s interest, particularly in Vietnam. Kosygin’s visit to Hanoi is the latest step in this process. We believe that, in embarking on these tactics, the Soviet leaders hoped to work Hanoi back toward a middle position in the Sino-Soviet dispute, to discourage the US from broadening the war, and to participate in the Communist victory which they expected. To these ends, the USSR probably planned to offer to strengthen North Vietnamese air defenses and to provide equipment for use in insurgency and subversion.

2. The recent VC attacks and US/GVN reprisals probably cut across Soviet calculations. The US course of action under consideration here would further undermine these calculations and force the Soviets to reconsider; indeed, they are probably already doing so. In the meantime, however, they have already reconfirmed their commitment to North Vietnam, albeit in general terms, with a government statement promising “further measures to safeguard the security and strengthen the defensive capability” of the DRV.

3. Soviet public statements after the attacks of last weekend had a cautionary flavor, and we believe that Kosygin’s private representatives to Hanoi were of a similar nature. Nevertheless, Hanoi has evidently chosen to maintain a high level of VC pressures in South Vietnam, including attacks against US facilities, perhaps in part to force the Soviets into a stronger commitment. China for its part is almost certainly seeking to sharpen the Soviet dilemma of a choice between support for the DRV, whatever the dangers of confrontation with the US, or a withdrawal which Peiping could portray as confirmation of its case against Moscow.

Key Uncertainties

4. At the outset, the Communists would have to determine how to interpret the new policy declared by the US. We believe that they would [Page 246] understand that the US did in fact intend a course of sustained pressure against North Vietnam. Even at the beginning, however, they would see some chance that their own threats and international pressures could succeed in averting air attacks or keeping them at a low level. Unless attacks continued regularly and frequently thereafter and the US Government displayed a consistent determination to persevere, the Communists would tend to doubt that the US would long sustain this course of action.

5. Another important initial uncertainty relates to timing. In the course of reasserting their interest in Vietnam, the Soviets may have extended specific commitments, including offers of military aid, of which we are not yet aware. Or they may do so between now and the time when the new US policy is announced. In either case, the USSR’s freedom to disengage in reaction to the new US program would be reduced, although not entirely eliminated.

Soviet Reactions

6. It is possible that, once the US has demonstrated the seriousness of its intentions, the Soviets would revert to a policy of minimum involvement. But we think it unlikely that they would do so; their commitment to date probably has already carried them past this point. Although the Soviets would perceive military risks in more direct involvement, they would expect to be able to keep these at a tolerable level and far removed from the Soviet homeland. They would also expect difficulties in their relations with Washington, but the new leaders have thus far shown themselves at least as concerned to win support of other Communists and anti-Western radicals as to carry forward a détente with the US.

7. We believe that the Soviet response to the US program of air attacks would consist both of a vigorous diplomatic and propaganda effort to bring the US to the conference table and the provision of military support to North Vietnam. The extent and nature of the latter are difficult to predict. It would almost certainly include anti-aircraft artillery and radars. In order to provide a more effective defense against US air attacks, however, North Vietnam would almost certainly press for surface-to air missiles or even advanced jet fighters. These systems would, at the present time, have to be installed and operated by Soviet personnel.2

8. In considering these advanced systems, the USSR would recognize that missile sites and fighter bases in North Vietnam would be [Page 247] highly vulnerable to US attack. The Soviets would appreciate that successful attacks on these targets would face them with a choice of accepting the damage, substantially boosting their involvement in the defense of the DRV, or becoming party to even more provocative escalation. It may be that, rather than open up these dangers, the USSR would refrain from providing SAMs and fighters. Yet a refusal to satisfy North Vietnamese requests for this kind of aid would be costly to the Soviet position, the more so if such aid had previously been promised.

9. On balance, we think that the chances are about even that the Soviets would provide some SA–2 defenses to North Vietnam. Such a move would run counter to the preferred Soviet tactics of increasing their commitments only when the dangers of confrontation have begun to recede. But the present degree of Soviet involvement, plus the political costs of failing to provide support in the circumstances under consideration, might outweigh their caution in the present case.

10. If the Soviets should provide SA–2s, we believe that they would do so in ways calculated to minimize the initial risks to them. One likely way of doing this would be to deploy some SA–2 defenses for the key Hanoi-Haiphong area, hoping that this degree of involvement would serve to restrain the US and still not engage Soviet personnel in actual fighting. SA–2s deployed in this area, however, probably would be used if attacking US aircraft came within their range. By providing Soviet personnel in the guise of “technicians,” the USSR would preserve the option of ignoring any Soviet casualties.

11. This would be a fairly limited Soviet involvement, but it would represent a greater commitment to North Vietnam than has obtained in the past. In this situation of increased risks, we believe that the USSR would be seeking means to curb the conflict. This effort would consist both of threats against the US and of attempts to mobilize international pressures on the US to negotiate, probably in the Geneva forum.

12. If these efforts failed, however, the Soviets might in time advise Hanoi to damp down operations in South Vietnam or even to entertain a political settlement on terms not completely unacceptable to the US. This would be a delicate operation for the USSR; the DRV would charge that what was needed was not less Viet Cong aggressiveness but more effective Soviet assistance, and Peiping would almost certainly take the same line. We cannot at this time predict whether the USSR would try this approach nor, if it did, what the results would be.

13. Elsewhere in the world, general Soviet policy would harden against the US. This would tend to preclude moves toward a relaxation of tensions and to increase the USSR’s verbal ugliness on other East-West issues. The new leaders, however, have in any event not been inclined to date to move very far toward detente. Nonetheless, we think it highly unlikely that they would react to the US course of action considered here [Page 248] by deliberately provoking a major crisis in some other area of the world, e.g., Berlin or Cuba.

DRV Reactions

14. Initiation of the new US policy almost certainly would not lead Hanoi to restrain the Viet Cong. Hanoi would probably elect to maintain the very intense levels of activity evident in the past few days. Pressures might be stepped up in Laos at the same time. The anger and emotion with which the US program would be received in Hanoi might affect its calculations. In any case, the DRV would wish to avoid an impression of weakness at the outset. Moreover, it would have some doubt about US staying power on its new course and would hope that Sino-Soviet competition would maximize the support provided by both allies. If the US persevered in the face of threats and international pressures, and as the degree of damage inflicted on North Vietnam increased, the chances of a reduction in Viet Cong activity would rise (see paragraph 18).

15. The insurgency in South Vietnam is heavily dependent on support, leadership, and direction from the DRV, but the VC nonetheless has substantial capabilities independent of Hanoi. Thus Hanoi could probably achieve a substantial stand down for tactical purposes and could effect a more lasting reduction. Nonetheless, the insurgency in South Vietnam has a momentum of its own, and some hostile VC action would probably continue, though at reduced levels.

Chinese Reactions

16. China would be equally violent in castigating the new US course. At the outset of the new US program, there is a fair chance that Peiping would also introduce limited numbers of Chinese ground forces as “volunteers” into North Vietnam, intending to raise the specter of further escalation, to underline its commitment to assist the North Vietnamese, and to challenge the Soviets to extend corresponding support. More extreme Chinese reactions—such as introduction of large-scale ground force combat units into North Vietnam or northern Laos—would be possible, though we think this unlikely in the early stages. If the US program continued and inflicted severe damage on North Vietnam, the chances of such a movement would rise. But we still think that China, conscious of the danger of provoking major US attacks against its own territory, probably would not take this step.3

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Use of Communist Aircraft

17. A special problem for the Communists lies in the fact that only three North Vietnamese airfields, all located in the northern part of the country, are fully capable of sustaining jet fighter operations.4 Fighters would thus have difficulty in engaging US/GVN aircraft attacking targets in the southern part of North Vietnam. Furthermore, the Communists recognize that US retaliation against these airfields would be feasible and effective. These considerations apply to the use of Soviet and Chinese fighters in North Vietnam as well as to the interceptors which the DRV might be able to put into the air with Soviet or Chinese assistance. Despite these capabilities, the Communists probably would employ the fighters based in North Vietnam against the US air attacks. If US air attacks reached the northern part of the DRV, China might react over North Vietnam with fighters from its own bases.5

18. The Communists could react by launching air attacks against South Vietnam from North Vietnamese or Chinese bases. We think this unlikely because of the vulnerability of North Vietnamese bases and China’s reluctance to risk retaliation against its own territory.

A Possible Communist Tactic

19. If at some point the Communists had become persuaded of the durability of the new US policy, they might adopt tactics designed to provide a respite. This might come about if US attacks were inflicting severe damage and if, at the same time, the US had made clear an intention to reduce or cease its attacks in return for a sharp reduction of Viet Cong activity in South Vietnam. In these circumstances, the DRV might order such a reduction and use an ensuing period of calm to press for a negotiated cease-fire and an international conference. At the same time, it might use the respite for a major buildup, assisted by its allies. Such a buildup might include extensive SA–2 deployments, additions to jet fighter strength in North Vietnam and southern China, and large-scale deployments of DRV and Chinese ground forces suitable for rapid invasions. The Communists might expect that they could complete these preparations without US interference, and that thereafter the US would be deterred from resuming its program of air attacks when Viet Cong activity was again stepped up.

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The Coordination of Communist Policy

20. It is obviously to Communist advantage to appear unified, and they will make great efforts to convey this impression. Heightened military conflict would itself exert strong pressures for effective unity. Nevertheless, we have at several points indicated our belief that the USSR and China act as competitors in North Vietnamese affairs and that they would continue to do so during a period of sustained US air attacks on North Vietnam. We have also pointed to complex and conflicting interests which make for delicate relations—and difficult communications—between Hanoi and both its allies. We think it likely that policy coordination among three Communist countries involved will be chronically imperfect and occasionally quite erratic. Hence, Communist policies and reactions will at times be faltering and uncertain and at others bold to the point of rashness. In any case, since Communist policies will be constantly fashioned and refashioned to meet a constantly changing situation, they will be difficult to foresee very far ahead.

  1. Source: Department of State, Bundy Files: Lot 85 D 240, February 1965. Top Secret; Controlled Dissem; Limited Distribution. The Central Intelligence Agency and the intelligence organizations of AEC, NSA, and the Departments of State and Defense participated by the Director of Central Intelligence and concurred in by all the members of the U.S. Intelligence Board, except for the Assistant to the Director of the FBI, who abstained on the grounds that the subject was outside his jurisdiction.
  2. In the case of the SA–2 missile system, the USSR would need two and more probably about three weeks to provide a limited operational capability in North Vietnam after a decision to do so. Advanced jet fighters could be provided more quickly. [Footnote in the source text.]
  3. The Director of Intelligence and Research, Department of State, believes that the chance of introduction of Chinese ground forces into North Vietnam or northern Laos is considerably higher than is estimated in this paragraph. [Footnote in the source text.]
  4. At Kien An in northern North Vietnam and at Vinh and Dong Hoi in southern North Vietnam, there are airfields on which jet fighters (including MIG-21s) can land and take off, but none of these fields has ancillary facilities sufficient to support sustained operations. Thus, while North Vietnam has six fields with runways adequate for jet fighters, only three (Phuc Yen, Hanoi/Gia Lam, Haiphong/Cat Bi) can support sustained jet fighter operations. [Footnote in the source text.]
  5. The Director of Intelligence and Research, Department of State, believes that “might” in this sentence should be changed to “would probably.” [Footnote in the source text.]