Foreign Relations of the United States, 1969–1976, Volume E–14, Part 2, Documents on Arms Control and Nonproliferation, 1973–1976

54. National Security Decision Memorandum 256¹

Washington, June 10, 1974.

TO

• The Secretary of Defense
• The Director of Central Intelligence
• The Director, Arms Control and Disarmament Agency
• The Chairman, Atomic Energy Commission
• The Under Secretary of State for Political Affairs

SUBJECT

• Nuclear Test Ban Policy

The President has reviewed the results of the NSSM 195 study and subsequent Verification Panel work. On the question of limitations on underground nuclear tests, he has decided that an agreement with the USSR to a threshold ban is acceptable in principle. Such an agreement should meet the following conditions:

—The threshold test ban should enter into force no earlier than January 1, 1976.

—PNEs may be allowed only if information adequate for proper verification is furnished by the Soviets. In any event, PNEs must be covered by the same threshold as nuclear weapons tests.

—The U.S. should oppose the Soviet proposal concerning a quota between an upper and lower threshold.

—The U.S. can accept a threshold based on yield if adequate geological information is provided by the Soviets and their weapons testing is restricted to specific test sites. The U.S. position is that the threshold must be at least 100 KT.

—With respect to explosions above the threshold, the U.S. can accept a provision allowing for no more than two unintended and slight breaches of the threshold per year.

The President has directed that the Atomic Energy Commission and the Department of Defense develop a nuclear weapons testing program which would complete all essential testing above a 100 KT threshold by January 1, 1976. This program should be submitted for the President’s approval by June 19, 1974.

Henry A. Kissinger

1. Summary: Kissinger informed the addressees that President Nixon had reviewed the results of the NSSM 195 study and other work undertaken by the Verification Panel and decided that an agreement with the Soviet Union on a threshold test ban could be pursued provided that such an agreement met several conditions. In addition, Nixon directed that the Atomic Energy Commission and the Department of Defense develop a nuclear weapons testing program, which would complete all essential testing above a 100 KT threshold by January 1, 1976.

   Source: Ford Library, National Security Adviser, NSC Program Analysis Staff Files, Convenience Files, Box 6, VP (CTTB), June 4, 1974. Secret; Sensitive. A copy was sent to Moorer. NSSM 195 is Document 30. The NSSM 195 study is in Nixon Presidential Library, NSC Institutional Files, Study Memoranda (1969–1974), Box H–203, NSSM 195, Folder 2.