Foreign Relations of the United States, 1964–1968, Volume I, Vietnam, 1964

65. Memorandum From the Joint Chiefs of Staff to the Secretary of Defense (McNamara)¹

JCSM–168–64

Washington, March 2, 1964.

SUBJECT

• Removal of Restrictions for Air and Ground Cross-Border Operations

1. By JCSM–136–64, dated 18 February 1964, subject: “Vietnam and Southeast Asia (U),”² the Joint Chiefs of Staff forwarded recommendations for certain steps to be taken immediately to revitalize the counterinsurgency campaign in South Vietnam. That memorandum advised that other actions were also under study, among which was the subject removal of existing restrictions related to ground and air cross-border operations. This memorandum contains the views and recommendations of the Joint Chiefs of Staff on that subject.

2. While our available hard intelligence does not reveal the exact dimensions of the infiltration of men and materials into South Vietnam from the North, and the true extent to which the Viet Cong and their North Vietnamese supporters are utilizing sanctuaries in Laos and Cambodia, there is mounting evidence that these are of such proportions as to constitute an increasingly important factor in the war. Modern weapons of Chinese communist origin, including recoilless rifles and quadruple-mounted heavy machine guns, are appearing in the hands of the Viet Cong in South Vietnam in increasing numbers, partially offsetting the tactical advantage we have derived heretofore from the use of air mobility and armored personnel carriers. Viet Cong military capabilities are growing significantly in terms of well trained, well armed, and well directed hard core units, indicating the extent and effectiveness of the support being provided by Hanoi in terms of arms, equipment, trained cadre, and operational direction. There is evidence that small Viet Cong units have used Cambodia as a sanctuary for a considerable period of time. Additionally, there has occurred recently an incident wherein a battalion-sized Viet Cong unit, several hundred strong, after making a devastating attack, withdrew into their inviolable sanctuary in Cambodia. All our experience in counterinsurgency indicates that when the insurgents enjoy the advantage of such sanctuaries and support across international borders, their elimination will be a most difficult, if not impossible, task.

3. In the face of the serious menace to our ultimate victory represented by the above, we continue to operate under the limitations of self-imposed restrictions. These restrictions are outlined in Appendix A hereto.³ Their effect is to deny to ourselves and our South Vietnamese Allies the essential means to satisfy urgent military requirements for interdiction of infiltration routes, pursuit, and destruction of enemy forces who take refuge in their sanctuaries across the borders.

4. The Joint Chiefs of Staff believe that the time has come to lift the restrictions which limit the effectiveness of our military operations. Certain military operations across the borders of Laos and Cambodia are considered essential to successful prosecution of war. Specifically, the Joint Chiefs of Staff recommend that authority be sought for the conduct of operations as described in Appendix B hereto⁴ which have been proposed by the Commander in Chief, Pacific. An analysis of the military benefits to be gained versus the possible risks involved is also contained in Appendix B.

5. Since the actions considered here represent only one segment of the Joint Chiefs of Staff recommendations in relation to revitalizing the Vietnamese campaign, it is suggested that this paper be held and considered in connection with the other papers bearing on the Vietnamese campaign.

For the Joint Chiefs of Staff:
Maxwell D. Taylor⁵
Chairman
Joint Chiefs of Staff

1. Source: Washington National Records Center, RG 330, OASD/ISA Files: FRC 69 A 926, 092 Vietnam. Top Secret; Sensitive.
2. Document 51.
3. Not printed.
4. In Appendix B, not printed, the JCS recommended that the South Vietnamese adopt a policy of hot pursuit of hostile Viet Cong forces into the Demilitarized Zone, Cambodia, and Laos, and that U.S. advisers be allowed to accompany them; also that the 2d U.S. Air Division be allowed hot pursuit on the same basis. In addition, the JCS recommended low-level reconnaissance of Laos and Cambodia by U.S. aircraft, encouragement of overt operations by South Vietnam against the Viet Cong in Laos (with U.S. advisers and cooperation with friendly Lao forces), and covert ground operations into Cambodia.
5. Printed from a copy that bears this stamped signature.