19. National Security Decision Memorandum 781


  • The Vice President
  • The Secretary of State
  • The Secretary of Defense
  • The Director, Central Intelligence Agency
  • The Director, Office of Emergency Preparedness
  • The Director, Arms Control and Disarmament Agency
  • The Director, Office of Science and Technology


  • Authorization for Use of Riot Control Agents and Chemical Herbicides in War

After further review of the issues set forth in response to National Security Study Memorandum 59,2 the President has considered United States policy on authorization for use by United States forces of riot control agents and chemical herbicides in war and has decided that:

The use of riot control agents by United States forces shall require Presidential approval except in cases of riot control and installation security on United States bases and posts.
The use of chemical herbicides by United States forces, either for defoliation or for anti-crop purposes, shall also require Presidential approval.
These decisions shall affect neither the current authority of United States forces in Vietnam to employ riot control agents nor the joint authority of COMUSMACV and the United States Ambassador, Saigon, to authorize support of Government of the Republic of Vietnam requests for herbicide operations. These requests will be handled in consonance with MACV Directive 525–1 (August 12, 1969), particularly Paragraph 5.
Any request for Presidential authorization shall be submitted by the Secretary of Defense and shall include the views of the Secretary of State. Each such request shall include (a) the specific agents to be used, (b) the specific theater of operations, (c) general categories of situations for use, and (d) justification for use.
Currently only Chlorobenzylidenemalononitrile (CS) and Chloracetophenone (CN) are classified and considered as riot control agents for military purposes. However, any agents which are accepted and used domestically for riot control and law enforcement purposes can be considered in this category in the implementation of this policy.
Chemical herbicides are considered as those chemical compounds which are used domestically within the United States in agriculture for weed control and similar purposes.
The annual review of United States chemical warfare and biological research programs, conducted by the Under Secretaries Committee as directed by National Security Decision Memorandum 35,3 will include a review of United States military riot control agent and chemical herbicide programs.

The President also has reaffirmed that his approval is required for the use of any lethal and incapacitating chemical weapons.

Henry A. Kissinger
  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 363, Subject Files, NSDMs 51–96. Secret. A copy was sent to the Chairman of the Joint Chiefs of Staff.
  2. NSSM 59, “U.S. Policy on Chemical and Biological Warfare and Agents,” May 28, 1969, is published in Foreign Relations, 1969–1976, volume E–2, Documents on Arms Control and Nonproliferation, 1969–1972, Document 141. The response to NSSM 59, October 30, 1969, is ibid., Document 156.
  3. NSDM 35, “United States Policy on Chemical Warfare Program and Bacteriological/Biological Research Program,” issued on November 25, 1969, is ibid., Document 165.