270. National Security Decision Memorandum 581


  • The Secretary of State
  • The Secretary of Defense
  • The Attorney General
  • The Director of Central Intelligence


  • Actions to Protect U.S. Forces in South Vietnam

I hereby rescind National Security Decision Memorandum 572 and substitute therefor the following instruction which I am promulgating to protect U.S. forces operating in South Vietnam:

  • —Authorization for attacks on identified North Vietnamese/Viet Cong base areas in Cambodia up to a depth of 30 kilometers. Primary responsibility for these attacks, whenever possible, should be with GVN forces with U.S. support where necessary. Combined U.S./GVN operations are also authorized. Under this specific authorization, combined U.S./GVN operations, with the exception of the already approved operation against base area 352/353, will be submitted to me for approval on a case-by-case basis.
  • —Authorization for the provision of U.S. tactical air/helicopter and artillery up to a depth of 30 kilometers in all base areas north of and including 352/353.
  • —This directive does not affect GVN operations inside of Cambodian territory which have been previously authorized.3

The Washington Special Actions Group is charged with coordinating these activities.

Richard Nixon
  1. Source: National Archives, Nixon Presidential Materials, NSC Files, NSC Institutional Files (H-Files), Box H–073, WSAG Meeting, Principals, 4/28/70. Top Secret; Sensitive; Principals Only. A copy was sent to Wheeler.
  2. Document 260.
  3. In telegram 5812 to McCain and Abrams, April 28, Wheeler informed them that the President had approved “certain military actions to protect U.S. forces operating in South Vietnam,” and repeated the authorizations as outlined in NSDM 58. Wheeler noted that his message was “an execute directive” and that the operation should commence not later than early on Friday, May 1, Saigon time. Wheeler also asked McCain and Abrams to advise when coordination with the JGS of ARVN had been completed. (National Archives, Nixon Presidential Materials, NSC Files, Box 590, Cambodian Operations, Chronology, Vol. III, Nodis/Khmer, HAK)