73. Memorandum From Director of Central Intelligence Helms to the President’s Assistant for National Security Affairs (Kissinger)1


  • The Possible Quarantine of North Vietnam
Per our conversation on Wednesday, 21 May, attached is a memorandum analyzing the impact that a quarantine of North Vietnam would have on that country’s economy and logistic support capabilities.2 This memorandum also outlines the probable reactions of various interested parties to the imposition of such a quarantine.
For reasons outlined in considerable detail in the attached memorandum, we are convinced that unless a quarantine of North Vietnam’s seaborne commerce was accompanied by an interdiction of the land lines of communication (rail and road) to Communist China, the North Vietnamese could solve the problems such a quarantine would pose; i.e., Hanoi could make enough adjustments or alternate arrangements to ensure continuation of the level of external support necessary to permit Hanoi to continue present levels of North Vietnamese support to the Communist military campaign in South Vietnam.
  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 207, Agency Files, CIA, Vol. I, January 1969–31 December 1969. Secret; Sensitive. According to an attached June 11 memorandum from Haig to Kissinger, Kissinger planned to discuss this memorandum with Helms that day.
  2. This 14-page paper with comments by Kissinger in the margins is attached but not printed.