188. Memorandum From the Deputy Director of the Office of Southeast Asian Affairs (Dexter) to the Deputy Assistant Secretary of State for Far Eastern Affairs (Unger)1

SUBJECT

  • Interception of Hostile Resupply Aircraft in Laos

You will recall that the Soviet airlift, begun in December 1960 to neutralist/PL forces, was terminated in October–November 1962. The Soviets [Page 373] withdrew from the scene, transferring most of their transport aircraft involved in the airlift to the DRV. We have had no reports of any covert Soviet air activity over Laos since that time.

From time to time since the fall of 1962, we have received low-level reports regarding isolated unidentified transport-type aircraft overflying Laos. However, there had been no reliable intelligence that the enemy was conducting air resupply of PL/NVN forces on any kind of regular basis until early April 1965.

Starting in early April, we have been receiving an increasing number of CAS reports strongly suggesting that PL/NVN forces in the Xieng Khouang/Sam Neua area are receiving supplies by air drop. (On one occasion two transport-type aircraft were observed on Sam Neua airfield.) Embassy Vientiane has reported that on the basis of reports from ground observers (the above CAS reports) and other intelligence (presumably including radar trackings by Udorn) there now appears to be a more or less regular pattern of air resupply activity taking place during twilight hours in the Xieng Khouang/Sam Neua area and involving at least 1–2 unidentified transport aircraft on most occasions.

As a result of the first reports in early April, we informed Vientiane that higher authority had directed that US forces intercept and destroy hostile aircraft engaged in the air resupply of PL/NVN forces in northern Laos. In view of the obvious political and other risks involved, the instructions cautioned that any intercept effort should be based on reliable intelligence that the aircraft was or were in fact hostile and engaged in air resupply. Hot pursuit into NVN was also authorized, as necessary.

The Ambassador was also instructed to consult Prince Souvanna. Souvanna, after considerable deliberation, agreed in principle that we should attempt to intercept and destroy any hostile aircraft engaged in air resupply but indicated this should be done only in flagrante with full assurance that the aircraft was parachuting or dropping supplies to the enemy. Souvanna and Sullivan acknowledged that this operation would be tricky.

To date there has been no intercept attempt. Second Air Division has now concluded, and Sullivan concurs, that intercept operations are not justified since the probability of success is reduced as a result of the need to limit the hours during which an intercept attempt can be made. This is in order to permit normal Air America and other resupply activities in the area to take place without interruption.

Ambassador Sullivan now proposes that two RLAF T–28’s with AA pilots, and three USAF ground support personnel, be repositioned on alert at Site 982 to accomplish the intercept mission (Embtel 2079).3 He [Page 374] has requested our approval. We recommend that this proposal be disapproved. We are already stretching our luck, it seems to us, in using AA pilots on T–28’s on SAR missions. So far our luck has held out but we question the desirability of running the added risks involved in intercept missions. We assume Ambassador Sullivan did not suggest the use of Lao or Thai pilots because of the problems of positive identification that the aircraft is hostile and engaged in flagrante in air resupply (and not one of ours), and the language barrier (the AOC Vientiane would make the final identification decision).

In view of the earlier personal involvement of the President in directing that these hostile aircraft be intercepted and destroyed, perhaps we should explore the possibility of using Lao or Thai pilots on T–28’s for this mission before deciding to cancel this project. There should be at least two pilots whom our people know well enough to have confidence in their pilot proficiency, judgment and reliability. They could be given intensive aircraft identification indoctrination. The language problem could be overcome by having an interpreter at the AOC to pass the final authorization, etc. It is possible that the need to use Site 98 may make this suggestion impractical. However, we think it is worth putting to Vientiane. Otherwise we recommend that Project “Duck Soup” be dropped.4

  1. Source: Department of State, EA/Vietnam, Laos, Cambodia Files: Lot 75 D 394. Top Secret; Limdis.
  2. Site 98 was Long Thienh (Chien), Meo (Hmong) leader Vang Pao’s headquarters.
  3. Dated June 25. (Department of State, Central Files, POL 27 LAOS)
  4. Dexter wrote the following note at the end of the memorandum: “Bill Hamilton told me it has been suggested at DOD that USAF SAW pilots be used instead of AA. I disagree.” In telegram 1121 to Vientiane, June 30, the Department stated it was not prepared to run the risk of having Air America or U.S. Air Force Special Warfare Detachment pilots fly T–28’s in Laos except for search and rescue operations. The Department suggested that the Embassy explore the possibility of using specially trained Lao or Thai pilots for Operation Duck Soup. (Ibid.)