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


  • Quarantine of Cambodia

Secretary Laird has sent you a study prepared by the Joint Chiefs of Staff, at your request, on the feasibility and utility for quarantining Cambodia against the receipt of supplies and equipment to support the North Vietnamese and Viet Cong forces operating in and from Cambodia. [Page 153] (Secretary Laird’s memorandum and the Joint Chief’s study are attached at Tab A.)2

The basic conclusions of the Joint Chiefs are:

An air/sea blockade and other steps to quarantine Cambodia are both militarily feasible and of some utility in intensifying enemy supply problems in the III and IV Corps areas.
Ground operations to deny the enemy use of the Laos Panhandle for support of enemy forces operating in and from Cambodia are not feasible within current force levels. However, present interdiction operations against enemy lines of communication in Laos should be continued to the maximum extent.
While diplomatic exchanges between the U.S. and Cambodia may present an opportunity to gain Cambodian assistance in reducing enemy use of Cambodia as a sanctuary, the most effective method would be preemptive ground and air operations of limited depth and duration in Cambodia and in the tri-border area of Laos.

On the basis of these conclusions, the Joint Chiefs made four recommendations:

Air/sea blockade or quarantine be retained as an option to be undertaken when appropriate against the receipt in Cambodia of supplies and equipment for the support of VC/NVA forces operating in and from Cambodia against South Vietnam.
Interdiction operations against the enemy’s lines of communication in Laos be continued to the maximum extent.
Current political initiatives be used to gain Prince Sihanouk’s support or acquiescence in allied military efforts to reduce the enemy’s sanctuary and the flow of supplies to VC/NVA forces operating in and from Cambodia.
In concert with other appropriate initiatives outlined above, short-term air and ground raids be authorized against clearly identified VC/NVA forces and supplies in sparsely populated areas of Cambodia along the SVN border, and in southern Laos.

Secretary Laird has recommended that the National Security Council review this issue before any new military actions are authorized because of the political implications of the Joint Chief’s recommendations. These political implications are briefly the need to estimate Prince Sihanouk’s level of tolerance for operations inside Cambodia, and the question of consulting with Prince Souvanna Phouma [Page 154] on further operations in Laos, as we have done in the past with good results. The Joint Chiefs of Staff are also preparing a list of specific military actions in Cambodia which would not be subject to National Security Council review.


That Secretary Laird and Secretary Rogers be requested to prepare a joint study on the military and political implications of preemptive operations against Cambodia and Laos for consideration by the National Security Council.3

  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 505, Country Files, Far East, Cambodia, Vol. I, 8–69. Top Secret; Sensitive.
  2. Tab A, a memorandum from Laird to Nixon, March 18, and Annex A, an undated JCS study of a quarantine of Cambodia, are not attached. (National Archives, RG 59, Central Files 1967–69, POL 27 VIET S)
  3. Nixon initialed the disapprove option and wrote: “Let’s not make any ‘decisions’ on this until we get another crack or two at Cambodia. Later—have the study made.” In an April 8 memorandum to Laird, Kissinger informed him that the President had reviewed the study on quarantining Cambodia and that he “desires that this matter be held in abeyance for the time being.” (Washington National Records Center, OSD/ISA Subject Decimal Files: FRC 330 72 A 6308, Box 7, Cambodia 1969 000.1)