Foreign Relations of the United States, 1964–1968, Volume XXVII, Mainland Southeast Asia; Regional Affairs

198. Memorandum From the Joint Chiefs of Staff to Secretary of Defense McNamara¹

JCSM–779–66

Washington, December 19, 1966.

SUBJECT

• Actions to Deal with VC/NVA Use of Cambodian Territory (S)

1. (TS) Reference is made to JCSM–812–65, dated 12 November 1965,² in which the Joint Chiefs of Staff informed you of their views and recommendations concerning Cambodian support of the Viet Cong (VC). The Joint Chiefs of Staff recommended that forceful action be taken to stop the use of Cambodian territory by enemy forces as a logistics base and sanctuary.

2. (TS) You concurred in actions to expand and intensify the over-all intelligence collection program in Cambodia, increased surveillance of the sea lines of communication (LOCs) between the Republic of Vietnam (RVN) and Cambodia, increased controls on the Mekong and Bassac waterways, and planning for the conduct of covert paramilitary operations and low-altitude aerial reconnaissance. You further stated that should these measures prove ineffective other recommendations would be considered on a case-by-case basis. The immediate pursuit of VC/North Vietnamese Army (NVA) forces withdrawing into Cambodian territory was authorized only in emergency self defense/preservation situations.

3. (TS) Measures recommended for the conduct of an aggressive political/psychological campaign to persuade the Cambodian Government to stop support of the VC/NVA were referred to the Secretary of State. The Secretary of State advised a gradual and cautious approach and, with respect to covert cross-border operations, full consideration of the political problems involved. He further stated that there was a lack of convincing evidence of the significant use of Cambodian territory by the VC/NVA.

4. (TS) The VC/NVA exploitation of the pseudo-neutrality of Cambodia has increased to serious proportions. This is amply substantiated by a recent DIA assessment (Appendix A)³ and attested to by the conclusions reached at a Southeast Asia Coordination (SEACOORD) meeting of 10 November 1966. VC/NVA use of the Cambodian sanctuary constitutes a clear and present danger and thereby requires a continuous commitment of sizable friendly forces to the border area, impedes progress of the land campaign, and results in unnecessary US and friendly casualties. Major US operations conducted adjacent to the Cambodian border during 1966, including the largest ground operation to date, Attelboro, have provided continuing indications that the VC/NVA are using Cambodia as a base of operations, a safe haven, and a source of logistical support.

5. (TS) Actions authorized under current policy have proven inadequate to counter the growing threat imposed by VC/NVA use of Cambodia. An impasse exists wherein the collection of convincing intelligence is prerequisite to changes in policy, while adequate intelligence cannot be obtained until this policy is changed.COMUSMACV, CINCPAC, and Embassy Saigon recommend and the Joint Chiefs of Staff concur that additional measures must be taken to obtain adequate and convincing intelligence suitable for use in diplomatic efforts aimed at reversing Cambodiaʼs countenance of the present situation.

6. (TS) The Joint Chiefs of Staff consider that current national policy with respect to Cambodia must again by reviewed in light of over-all US objectives in Southeast Asia and the continued use of the Cambodian sanctuary by the VC/NVA. It is noted that Secretary Vance has requested the Under Secretary of State to establish a joint State-Defense-CIA study group to explore problems associated with Cambodia. This will take time. In the meantime, certain minimum actions should be taken now. Therefore, the Joint Chiefs of Staff recommend that:

a. The over-all intelligence collection program against Cambodia be expanded and intensified immediately to include:

(1) Authorization for ground reconnaissance operations such as Daniel Boone into Cambodia.

(2) Authorization to conduct high altitude U–2 photography over Cambodia on a continuing basis.

(3) Authorization to conduct medium and low altitude day/night photography, ARDF, IR, and SLAR on a continuing basis into Cambodia to a depth of 75 nautical miles from the border with Laos and South Vietnam (SVN). Excluded from reconnaissance coverage is an area 25 nautical miles around Phnom Penh.

b. Immediate pursuit of actively engaged VC/NVA forces which are withdrawing into Cambodian territory be authorized, thereby enhancing our capability to destroy the enemy, gaining hard intelligence, and increasing the security of the border area.

c. A more extensive coordinated public affairs and information program and supporting psychological operations be instituted to illuminate Cambodian support to the VC/NVA, to dissuade Cambodia from continuing such support, and to lay the foundation for possible future courses of action.

d. A memorandum, substantially as contained in Appendix B, together with a copy of Appendix A, be forwarded to the Secretary of State.

For the Joint Chiefs of Staff:

Earle G. Wheeler ⁴
Chairman
Joint Chiefs of Staff

1. Source: Washington National Records Center, RG 330, OSD Files: FRC 70 A 4662, Cambodia, 1966. Top Secret.
2. Document 159.
3. Appendices A and B are attached, but not printed.
4. Printed from a copy that indicates Wheeler signed the original.