Foreign Relations of the United States, 1969–1976, Volume VI, Vietnam, January 1969–July 1970

227. Memorandum From the President’s Assistant for National Security Affairs (Kissinger) to President Nixon¹

Washington, April 11, 1970.

SUBJECT

• The Prospects for Cambodia and Vietnamese Attitudes

We have received the views of Secretary Laird on the Communist capabilities in Cambodia and Embassy Saigon’s views on these capabilities and on the prospects there, particularly as they affect Vietnam.² Their views are parallel in many respects. Following are some of the main points:

I. Assessment

• —Both the Secretary and the Embassy point out that Communist forces in the border area are stronger than the Cambodian forces, although their superiority is not overwhelming. Secretary Laird estimates about 19,000 NVA/VC combat forces in the border areas opposite Phnom Penh and further south to the sea. He estimates that there are only about 2,000 to 4,000 Cambodian troops in that area to contain the Communists, with another 4,000 in Phnom Penh. (We consider that estimate very low, since the Cambodians have been calling up reserves and redeploying their forces.) The Embassy gives an estimate of about 17,000 VC/NVA combat forces in the entire border area (not just opposite Phnom Penh), and also estimates that there are about 3,700 Communist Cambodian forces available to Hanoi.
• —Both the Secretary and the Embassy believe that the Communist forces would be able to defeat the Cambodian forces, but would not be able to overwhelm them quickly.

II. Prospects

• —The Embassy and the Secretary agree that Hanoi cannot tolerate the loss of its Cambodian sanctuaries, and must do something to remove the Lon Nol government or force a change in Phnom Penh’s policies.
• —The Embassy and the Secretary believe that the current outlook is for intensified Communist guerrilla warfare, using some mix of local and Vietnamese Communist forces to make Lon Nol change his policies or else to topple the Lon Nol government by bringing “people’s war” to Cambodia. This would be accompanied by a threat to take Phnom Penh.
• —The Embassy further points out that the loss of Cambodian sanctuaries and supply lines, even if temporary, will force the Communists to rely more heavily on Laos. The Embassy thinks that the upsurge in infiltration of supplies through Laos last winter already reflected Communist fears that Cambodia was no longer a reliable funnel. It thinks that Hanoi will now attempt even harder than before to try to force a stop to U.S. bombing of the Laos trails.

III. The U.S. and South Vietnamese Role

• —The Embassy believes that a principal restraint on the Communist forces in Cambodia is their concern about what U.S. and South Vietnamese forces might do if Communist forces leave their base areas. The Embassy believes that it is to our advantage to leave the Communists in the greatest possible doubt about this, giving them no assurances that they can act freely in Cambodia without provoking our involvement. It believes we should conduct ourselves to induce uncertainty and worry in the enemy.
• —The Embassy also believes that we should not restrain the South Vietnamese from cross-border operations too long if the Cambodian government requests help. Such a suspension, in the Embassy’s words, “could not be maintained for too long without an outcry in Vietnam against the U.S. and Thieu, especially if the VC/NVA start hurting the Cambodian armed forces seriously.” If Thieu were to veto cross-border operations in case the Cambodian army is badly hurt, the Embassy expects serious criticism to build up.
• —The Embassy also believes that we should expect secret and even open Cambodian overtures for U.S. and South Vietnamese assistance if the new government’s position becomes increasingly threatened.

1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 506, Country Files, Far East, Cambodia, Vol. III, 10 April 1970–23 April 1970. Secret; Sensitive. Sent for information. Holdridge sent this memorandum to Kissinger on April 8 with a recommendation that he sign it.
2. Attached is a copy of telegram 5182 from Saigon, April 7; see footnotes 2 and 3, Document 224. Also attached, but not printed, is an April 3 memorandum from Laird to Kissinger, which enclosed a JCS assessment of the North Vietnamese/Viet Cong capability to attack, seize, and maintain control over Phnom Penh. The assessment was prepared by DIA and coordinated with CIA. It concluded that with reinforcements from other border areas and sufficient time and preparation, the VC/NVN could take and hold Phnom Penh in the absence of South Vietnamese intervention. Without time and reinforcements, prospects for an early seizure of the capital were “marginal.” Wheeler sent it to Laird under cover of memorandum CM–5011–70, April 2.