172. Telegram From the Department of State to the Embassy in Thailand1

1085. For Ambassador Lodge and Ambassador Martin from the Secretary. Ref: A. Deptel 1026 to Bangkok; 1708 to Saigon.2 B. FTB 9478.3

I am most concerned that, notwithstanding approaches which have been made to GVN and RTG, Vietnamese and Thai authorities continue to provide active support to Khmer Serei action against Cambodia and that a major acceleration of this activity is now imminent.
Ambassador Martin should see Prime Minister soonest (and General Praphat as well, if he considers this desirable)4 to inform him that we have incontrovertible evidence of activity of Thai officials described above and to request that he take immediate action to terminate any form of RTG support for Khmer Serei. He should use such arguments as he believes best designed to bring about this result but Thanom should be left in no doubt that it is the firm view of the United States Government that Khmer Serei operation will in no way contribute to our [Page 378] broad objectives in Southeast Asia and can only bring discredit on the United States as well as Thailand and South Viet Nam.5
Ambassador Lodge should follow up earlier approach and take similar line with Ky, but in view Saigonʼs 21666 this may be deferred until approach to Thanom has been confirmed.
Following these approaches, I would appreciate your views as to what further action, if any, is required to bring a stop to this affair.7
  1. Source: Department of State, Central Files, POL 23–8 THAI. Secret; Immediate. Drafted by Trueheart, cleared by Bundy, and approved by Rusk. Also sent to Saigon as telegram 1831.
  2. In telegram 1026 to Bangkok, also sent to Saigon as 1708, December 27, the Department expressed concern about Thai and South Vietnamese support for the Khmer Serei. (Ibid., POL 23–8 CAMB)
  3. Not further identified.
  4. According to telegram 1275 from Bangkok, December 30, on the basis of Department telegram 1026 and prior to receipt of telegram 1085, Martin saw Praphat and expressed concern over Thai support of the Khmer Serei. Praphat downplayed Thailandʼs role and claimed it was mostly “passive supporting South Vietnamese initiated and financed operations.” (Department of State, Central Files, POL 23–8 THAI)
  5. In telegram 1088 to Bangkok, December 30, Rusk asked Martin also to see Thanom so as to leave no possibility of doubt in Thai minds about the seriousness of U.S. concern in the matter and to make the record completely clear. Rusk stated that he realized “that the Vietnamese are at least equally to blame in this affair and no effort should be spared to bring them to terminate support for the Khmer Serei.” (Ibid.)
  6. In telegram 2166 from Saigon, December 28, Lodge reported on representations he made with Ky about South Vietnamese support for the Khmer Serei. (Ibid.)
  7. Lodge reported in telegram 2338 from Saigon, December 31, that should he raise the issue again with Ky, the Vietnamese Prime Minister would ask for a clear view of the U.S. position in Viet Cong use of Cambodia as a sanctuary. Lodge stated that he had “gone as far as I can go on the basis of treating the Khmer Serei as a totally isolated and separate event.” (Ibid.)