Foreign Relations of the United States, 1964–1968, Volume XXVIII, Laos

47. Telegram From the Embassy in Laos to the Department of State¹

Vientiane, May 15, 1964, 5 p.m.

1314. Bangkok’s 1864 to Dept, 289 to Vientiane; Embtel 1201.² PL/VM are currently engaged in their usual efforts before rainy season sets in to improve their military positions and secure lines of supply. Principal effort now appears be aimed at Tha Thom (which reported to have fallen May 14), with some action also threatened northern Plaine des Jarres sector toward Munong Soui. Heart of Plaine des Jarres itself now under PL guns but since taking of Phou San there have been no important indications of further push in that area. First stages these actions already evident before April 19 coup and could represent nothing more than continuation persistent PL effort take over all areas which occupied separately or jointly by them and neutralists as of June 1962.

If this continues be Communist policy we can expect PL/VM forces stop short of Mekong itself. In Tha Thom sector this would probably mean advance up to but not including Borikane (UF 6653). While further improvements of PL/VM positions might be made in Plaine des Jarres and effort made cut route between Plaine and Munong Soui, would not anticipate, under this thesis, effort to push neutralists off Plaine.

We are however in new situation which may result in change in Communist calculations and therefore possibly intention on their part move farther than in past and even make all-out effort take over all of Laos including Mekong lowland. Thus far we have no indications any such change but believe it wise consider what this would call for on our part in way of contingency plans and decisions, together with possible deterrent measures to be taken now.

(1) April 19 coup introduced new element and may have been taken by Communists, who firmly persuaded U.S. and other anti-Communist nations in region supported it, as indication U.S. has backed away from Khrushchev-Kennedy decision of July 1961 and means install regime in Vientiane which will work for military solution. Communists might consider such a U.S. shift as logical accompaniment our firm policy South Viet Nam. This might persuade Communists that with political excuse of coup available to them and while military leadership in Vientiane thoroughly confused, this is moment take advantage their clearly superior position and take over.

(2) Souvanna’s recent statements and actions more hostile to Pathet Lao (see A–341)³ may be persuading Communists that Souvanna has lost last vestige neutrality (as seen through their eyes) and they no longer have any reason restrain themselves because of disappearance all hope of using him to their advantage.

(3) Although we have no overt indication of this, also conceivable that Communists have changed their assessment of U.S. position and no longer fear prompt response from us if they should approach Mekong. Factors contributing to such an appreciation by Communists, if this is case, would be our decision not to move against North Viet Nam directly, at least now; reluctance become involved in any more military actions in election year; and absence any sharp U.S. reaction to PL/Viet Minh advance almost to Mekong in Thakhek area last January.

Thus first question is whether we should seek some way tell Communists that we continue be prepared resist with force their stepping over invisible line guarding Mekong lowland. We would of course wish do this in such way as to avoid persuading them, in line with point 1 above, that U.S. bent on resumption warfare in Laos. Tend to agree with Amb Martin that deployment U.S. troops does not provide satisfactory answer; on one hand there is Thai reluctance increase their involvement to this degree if they cannot be assured our readiness follow through if challenged and on other hand I am not sure how seriously it would be taken by Communists unless it were considerably larger scale than in 1962. More persuasive, I believe, would be 7th Fleet action off North Vietnamese coast which would not involve Thais but rather be pointed directly at North Vietnamese who pull strings in Laos and would also represent pressure which could be applied selectively.⁴

At same time we must of course be ready with our plans for direct military action, including use of U.S. and/or SEATO troops, in case becomes clear Communists intend seize lowland to any significant degree. Under such circumstances believe government would request SEATO and/or U.S. forces sent to support it to cross Mekong and take principal towns along river at least, so that Communist forces could not credibly charge invasion but would be themselves clear aggressors against lowland territory still held by government. I realize this question becomes immediately involved in highly classified U.S. and SEATO planning and I mean only to suggest it be kept under constant review, particularly should there in future be any clear sign that Communists will not this time be inhibited, as in past, from establishing themselves on Mekong. Should this occur we would still have choice available as to whether we wished accompany action from Thailand with use 7th Fleet off North Viet Nam.

Unger

1. Source: Department of State, Central Files, POL 27–14 LAOS. Top Secret; Priority; Limdis. Repeated to Bangkok, CINCPAC for POLAD, and Saigon.
2. Telegram 1864 from Bangkok, May 4. (Ibid., DEF 6 US) For telegram 1201 from Vientiane, see Document 39.
3. On May 2 Souvanna announced that he had merged both neutralist and rightist factions and that he would lead both. On May 13 the Souvanna government announced that it had merged the neutralist forces with FAR. Souphanouvong demanded a return to tripartite government. (Airgram A–341 from Vientiane, May 14; ibid., POL 27 LAOS)
4. In telegram 1006 to Vientiane, May 16, the Department broadly agreed with the assessment of Pathet Lao/Viet Minh intentions, but doubted that “7th Fleet action could convey clear signal to Hanoi, i.e., that it would be taken as warning of resolve to hold Mekong lowlands.” For this reason and because it did not wish to “overwork this gambit,” the Department was not following Unger’s suggestion on moving the fleet to off the North Vietnamese coast. (Ibid., POL 27–14 LAOS)