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

194. Telegram From the Commander in Chief, Military Assistance Command, Vietnam (Westmoreland) to the Commander in Chief, Pacific (Sharp)¹

Saigon, October 2, 1966, 1305Z.

44351. Subj: Cambodia (U).

1. (TS) MACV has been concerned for some time with increasing North Vietnam Army (NVA) and Viet Cong (VC) use of Cambodia and the support provided NVA–VC forces by the Royal Khmer Government with or without official RKG sanction. The effect of this situation on our current military operations is threefold. It results in a considerable number of casualties, it diverts forces from other tasks, and it contributes to prolongation of the war. In the southern provinces, NVA–VC forces using Cambodia sanctuary constitute a major hindrance, while in the areas adjacent to Pleiku and Kontum provinces, such forces constitute a significant threat. An indication of the overall effect of the existence of the Cambodia sanctuary on our operations can be seen in the number of casualties (7, 317 US and ARVN) in the provinces bordering Cambodia during the period January through August 1966. While not all such casualties may be attributed to the sanctuary, the figure is of significance.

2. (TS) Analysis of numerous reports of varying reliability dealing with RKG support of the NVA–VC indicates:

A. Cambodia has contracted to sell and deliver to Communist forces in South Vietnam, and possibly southern Laos, 55,000 tons of rice for the year 1966.

B. The number of trucks and boats, times the tons reported on each, times the number of trips indicates that 140 tons of rice per day, or 51,000 tons annually, are being delivered to the NVA–VC forces in southern Laos and South Vietnam. Additional evidence indicates that unofficial sales could raise this total to over 100,000 tons annually.

C. On 12 June 1966, Viet Cong representatives in Phnom Penh reportedly told the Cambodian Government that its support was required to fight and win decisively the war in 1966. Sihanouk agreed to sell needed rice to the VC.

D. Arms, ammunition, explosives, medical supplies, equipment, and material also are being delivered to the Viet Cong by Cambodians from Cambodia.

E. At least six NVA regiments, four battalions, and eight infiltration groups are known to have entered South Vietnam from Cambodia. The 630th NVA Div uses Cambodia as a base area and sanctuary.

F. The north-south infiltration complex is being shifted from within SVN further to the west into Cambodia. Enemy base areas reportedly have been established in Cambodia at approximately 100 kilometer intervals along the border from Laos to the Mekong River. The four major base areas in Cambodia are: (1) Chu Pong, (2) Nam Lyr mountain, (3) Lo Go to 20 km south, and (4) the banks of the Bassac-Mekong Rivers near the border. In addition, three other probable base areas have been identified: (1) Tassing, at the northern boundary of Cambodia in the tri-border area, (2) Snoul and the areas to the south and east, and (3) the “Parrotʼs Beak” of Svay Rieng Province.

3. (TS) In addition to the foregoing, it now appears possible that the Cambodia sanctuary problem may be exacerbated by an NVN-VC decision to convert Cambodia into the major logistical base for all supplies—including arms and ammunition—for the NVA–VC forces in the II and III Corps tactical zones and for the VC in the IV Corps tactical zone. This hypothesis is based on the following factors: the high cost to the enemy of opening up motorable routes in the southern portion of the Laos panhandle last year, the success of market time operations in cutting off sea routes of communications into South Vietnam, the uncovering of substantial NVA–VC caches of munitions and other supplies in South Vietnam, the success the NVA–VC have had in obtaining food and medical supplies through Cambodia, the ability to move supplies through Cambodia overtly and into areas immediately adjacent to the border of South Vietnam because the Royal Khmer Army is equipped with ChiCom materiel identical with NVA–VC, and, finally, the lack of any activity thus far indicating an intent to reopen lines of communications in the southern panhandle of Laos this year. All these factors suggest that the NVA–VC intend to rely in the main on the Cambodia sanctuary for total logistic support. This matter must be watched closely.

4. (TS) As you are aware, MACV established a study group to conduct a searching inquiry into all ramifications of the Cambodia matter in an effort to develop greater local understanding of major problems involved and to determine what might be done to solve them. This group has just completed its study and an initial presentation has been made within MACV. The study analyzed the following courses of action:

A. Green: A continuation of current US policy of accommodation with respect to Cambodia in the hope that, [garble] the sanctuary will disappear as a function of evolution.

B. Yellow: A simultaneous expansion of current US policy towards (1) amity and the restoration of diplomatic relations and (2) conflict within current parameters to establish the base for more militant actions to eliminate the sanctuary.

C. Blue: A course of action evolving from the amity portion of Yellow designed to reach a rapprochement and eventually to create an atmosphere in which the Royal Khmer Government accepts or invites US assistance in eliminating the sanctuary problem.

D. Orange: An aggressive course of action, falling short of extreme military actions, evolving from the conflict portion of Yellow and designed to build a base of support in the US and abroad among allies for more vigorous US activities.

E. Red: The execution of limited trans-border raids on targets of opportunity in response to an actual or fabricated provocation.

F. Black: The seizure and occupation of selected NVA–VC base areas in northeast Cambodia.

5. (TS) The study concluded that:

A. A limited ground raid as an ad hoc response to a specific situation would be appropriate as a basis for contingency planning and could be pursued seriatim without prejudice to other options.

B. The most appropriate course of action from among the remaining would be Yellow.

C. The study could be of value to other agencies considering the Cambodian problem.

6. (TS) As the proposals developed by the study include ways in which political, psychological, economic and military capabilities might be employed to lead to a solution of both the immediate military problem and to lay the groundwork for a long term US program to deal with Cambodia, I am inclined to believe that this is a matter which should be considered by SEACOORD. It is my intention to so recommend to Ambassador Lodge following presentation of the study of him. I will keep you advised.

1. Source: Johnson Library National Security File, Country File, Vietnam, Vol. LX, Cables, 10/66. Top Secret. Exclusive for Sharp. Repeated to JCS for Wheeler.