18. Memorandum From the Director for Intelligence, The Joint Staff (Breitweiser) to Secretary of Defense McNamara0



  • SNIE 58–61, “Probable Communist Reactions to Certain US Courses of Action with Respect to Laos”1


Brief of SNIE 58–61

On 21 February 1961, the United States Intelligence Board approved an Estimate on “Probable Communist Reactions to Certain US Courses of Action with Respect to Laos” (SNIE 58–61). A Brief of this Estimate is attached for your information in advance of the regular distribution which will be forthcoming.

R A Breitweiser
Major General, USAF



SNIE 58–61: Probable Communist Reactions to Certain U.S. Courses of Action with Respect to Laos

This Special National Intelligence Estimate was approved by the United States Intelligence Board on 21 February 1961. It was prepared in response to a requirement of OASD, ISA for an estimate of Communist reactions to selected hypothetical US sponsored courses of action, and is not intended to cover the full range of possibilities of U.S. initiative in Laos. Significant judgments of the Estimate are:

Except possibly in the case of the more extreme U.S. military measures, we believe that Soviet leaders would not match U.S.-sponsored [Page 60] military actions in Laos with corresponding, step-by-step, Bloc military measures. Except in the case of the most modest U.S. military measures Bloc leaders would almost certainly expect that most of world opinion would be sharply critical of the U.S., and that this fact would deter the U.S. from pressing too far.* [* Joint Staff footnote to SNIE 58–61. It is the opinion of the Director for Intelligence, Joint Staff, that reactions of the Bloc and the non-Communist world to U.S. sponsored measures would depend significantly on the vigor, forthrightness and success of these measures. Accordingly the Bloc leaders would not necessarily expect “most of world opinion” to be “sharply critical of the U.S.” Forthright U.S. action in the Taiwan Straits and in Korea attest to the fact that a significant segment of world opinion could be expected to applaud heartily U.S. sponsored military action taken against a Communist threat against all of Southeast Asia and its attendant challenge to the Free World. The considerations of timing, vigor and success of possible U.S. sponsored measures are not weighed in the assessments that follow. The Director for Intelligence, Joint Staff, believes that without careful weighing of these factors the judgments as to probable Bloc and non-Communist reactions must be viewed with reserve.]2 Responses to lesser U.S. measures would be designed far more for their political than their military effects. The Soviets do not want to prejudice their chances of negotiating with the U.S. on issues more important to them than Laos. This may restrain them from stepping up military pressures in Laos on their own initiative; it will be less likely to restrain them from military responses to U.S. military initiatives in Laos.

The direct delivery of military supplies to Vientiane by U.S. aircraft, sustained U.S. reconnaissance flights over Laos, the use of unmarked Thai or other aircraft to augment present airlift in Laos, or the assignment of volunteer Thai specialists to FAL units would draw a vigorous diplomatic and propaganda reaction. None of these measures would be likely to cause the Communists to cease their military efforts in Laos, to feel the need to make any concessions, or themselves to step up the tempo in Laos.

If the U.S. were to commit “Volunteer” combat aircraft to ground support operations in Laos, the Bloc would probably seek to increase PL AAA capabilities, possibly covertly introducing DRV AAA units, and Soviet threats would be made against bases supporting the air operations. The chances are about even that “volunteer” Communist ground attack aircraft would be committed in Laos.

If Chinese Nationalist irregulars were committed to combat action in Laos, as long as these forces did not significantly affect the course of [Page 61] fighting in Laos and did not make raids into China, Soviet and Chinese Communist reactions would probably be confined to vigorous propaganda-political exploitation.

If a token force of U.S. and allied ground forces were overtly assembled in northeast Thailand, DRV troops would probably be deployed along the Laos border, and threats of DRV intervention might be made. None of the foregoing measures would cause the Communists to cease their military support of the PL.

If the U.S. were to commit a volunteer, composite-nationality ground force in Laos, and the security of the PL forces were threatened, additional numbers of (DRV) “Lao” or “border” forces would probably be committed to stabilize the situation. It is unlikely that Chinese Communist “volunteers” would be committed, although we cannot rule out this possibility.

The overt commitment of U.S. and allied nation combat aircraft in Laos would probably be regarded by the Bloc as indicating a major commitment by the U.S. to the support of non-Communist forces in Laos, and that this challenge obliged it to make a strong political and military response. They would probably move to negotiate, calculating that they could both get a settlement that would protect Communist assets in Laos and at the same time reap considerable political benefit. It is possible that they might commit Bloc air or ground forces, but would in any event build up their readiness posture in the general area and issue strong threats against the U.S. and participating allies to cease their air operations.

If overt U.S. and allied ground forces were committed to garrison or combat duty in Laos, Bloc reactions would probably be similar to, but more intense than, those described for air action above. In particular, the chances are about even that the USSR would at the same time sponsor DRV intervention in Laos, and it might even acquiesce in Chinese Communist intervention.

If the U.S. issued a solemn, private warning to the Bloc powers to cease their military support efforts in Laos or face possible U.S. air and amphibious action against the DRV, the Soviets would certainly regard defense of North Vietnam against such an attack as imperative. They would probably feel that their total interests could best be served by making public the U.S. warning and castigating it as a threat to world peace. Simultaneously, Moscow would probably announce its determination to defend the DRV against attack and stress that any such U.S. action would carry the risk of general war, calculating that worldwide pressures on the U.S. would dissuade it from its threat and force it into negotiations on terms acceptable to the Communist side.

  1. Source: Washington National Records Center, OASD/ISA Files: FRC 64 A 2382, Laos ′61, 121. Top Secret.
  2. Dated February 21, not printed. (Department of State, INR/EAP Files: Lot 90 D 99)
  3. Asterisks and brackets in the source text.