6. Editorial Note
The contacts between the United States and the National Liberation Front (NLF) known as Buttercup began in the fall of 1967 and continued through early 1968. The immediate objective of the Buttercup operation was to secure the exchange of prisoners; both parties also viewed it as a possible means for generating a dialogue on political issues. For documentation on the operation in 1967, see Foreign Relations, 1964–1968, volume V, Documents 341 ff. On January 5, 1968, the intermediary Truong Binh Tong and Mai Thi Vang, the wife of NLF Central Committee member Tran Bach Dang, were released from South Vietnamese custody in order to return to the headquarters of the NLF, the Central Office for South Vietnam (COSVN). Arriving at COSVN on January 10, Tong met with Dang’s secretary, Anh Ba, who, in addition to questioning him about the American reaction to the original letter Tong had transmitted, which called for an exchange of political views in addition to a prisoner release, directed him to return with a new offer. (Telegram CAS 6841 from Saigon, January 10; National Archives and Records Administration, RG 59, Central Files 1967–69, POL 27–7 VIET S/BUTTERCUP)
Ten days later, Tong arrived in Saigon with a message proposing that the GVN release four prisoners named on a list passed to the United States the previous October in exchange for the release of two American and two South Vietnamese prisoners. (Telegram CAS 7321 from Saigon, January 23; ibid.) This proposal followed a January 8 release by the NLF in Binh Thuan of 14 South Vietnamese officers, 2 of whom were on the exchange list, a move that Secretary of State Rusk termed “somewhat implausible in terms of the promptness of the action and the belatedness of the word to us establishing the connection.” (CAS telegram from Rusk to Bunker, February 3; Central Intelligence Agency, DO/EA Files: Job 78–00058R, C/VNO File, BUTTERCUP, Vol. III–1 February 1968) On January 23 the NLF did release the two American enlisted men in Quang Tin Province and two additional South Vietnamese soldiers in Can Tho Province.
Carrying a reply from the United States, on January 26 Tong left for Viet Cong headquarters in the NLF Military Region IV in order to make contact with COSVN by radio. The points listed in the reply sent with Tong included: “(a) clarification of proposed prisoner release by NLF; (b) more formalized and efficient prisoner exchange arrangements in the future; (c) NLF agreement to using the radio channel or alternatively face to face meetings by representatives from both sides designated to discuss prisoner exchange matters; and (d) selection of different, more efficient and less dangerous routes for travel” by Tong on future [Page 13] trips. (Telegrams CAS 297 and 298 from Saigon, January 26; National Archives and Records Administration, RG 59, Central Files 1967–69, POL 27–7 VIET S/BUTTERCUP)
On January 27 North Vietnam announced that it would release three American pilots; they returned to the United States on February 17. In light of this development, the administration became very eager to move forward on Buttercup, and suggested that the Embassy engineer a reciprocal release of GVN-held Viet Cong prisoners even without waiting for Tong’s return. (Telegram CAS 70173 to Saigon, January 27; ibid.)
Tong arrived back in Saigon on January 29. The message he carried from Dang was disappointing, since it did not address the points made by the United States in its message sent through Tong and instead called for a continuation of the same procedures for the second part of the exchange. (Telegram CAS 353 from Saigon, January 29; ibid.) Difficulties were encountered in persuading the GVN to agree to the release of NLF prisoners, two of whom were killed during Tet. Working through Vice President Nguyen Cao Ky, however, the Embassy convinced the GVN to agree to the release of three of the VC prisoners, only one of whom had been on Tong’s January list. (Telegram CAS 591 from Saigon, February 12; Johnson Library, National Security File, Country File, Vietnam, Buttercup Vol. II, and telegrams from Bunker to Rostow, Rusk, Helms, and McNamara; CAS 730, February 20; and CAS 768, February 22; Central Intelligence Agency, DO/EA Files: Job 78–00058R, C/VNO File, Buttercup, Vol. III–1 February 1968)
On February 22 Tong returned to COSVN with the Viet Cong prisoners released by the GVN as well as with instructions to inform Dang that political discussions were still under consideration by the United States. Despite initial U.S. optimism relating to this channel, no further response was received from Tong, and both sides began to back away from this contact. (Telegram CAS 896 from Bunker to Rostow, Rusk, McNamara, and Helms, February 27; telegrams from Bunker to Rostow, Rusk, Clifford, and Helms; CAS 148, April 24; and CAS 654, September 11; ibid.) In a memorandum to Deputy Executive Secretary John Walsh, May 26, Fred Greene, Director of the Office of Research and Analysis for East Asia and the Pacific in the Bureau of Intelligence and Research, observed: “It does not seem likely, therefore, that the Front was prepared, had covert political contacts eventuated, to give very much on its own position; rather such contacts might have seemed worthwhile in and of themselves as advancing the Front’s claim to formal status as the negotiating partner with the U.S. with regard to ending the war in the South.” (National Archives and Records Administration, RG 59, Central Files 1967–69, POL 27–7 VIET S/BUTTERCUP)
The channel remained moribund until January 16, 1969, when an NLF operative identifying herself as “Madame Jeanne” telephoned the [Page 14] Embassy in Saigon on the same extension given to Tong and identified herself as his associate. The GVN, however, immediately raised considerable resistance to pursuing this channel. (Memorandum from Helms to Secretary of State William P. Rogers, January 27, 1969; Central Intelligence Agency, DCI (Helms) Files, Job 80–B01285A, DCI (Helms) Chrono, Jan.–Jun. 1969)