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

150. National Security Decision Memorandum 297¹

Washington, June 12, 1975.

TO

• The Secretary of Defense
• The Deputy Secretary of State
• The Director, U.S. Arms Control and Disarmament Agency
• The Administrator, Energy Research and Development Agency

SUBJECT

• Instructions for the U.S. Delegation to the PNE Negotiations, Moscow, June 3, 1975

The President has approved the following instructions for the negotiations on underground nuclear explosions for peaceful purposes (PNEs) which resumed in Moscow on June 3, 1975. These instructions supplement those contained in NSDM 287.

1. If individual explosions in a contained PNE salvo can be identified and their yields adequately measured through agreed verification procedures, contained salvos with aggregate yields up to 500 KT could be permitted. With respect to verification of individual yields for contained salvos with aggregate yield above 100 KT, the Delegation should propose use of the SLIFER technique for determining yield.

2. The Delegation should reiterate our position that all PNEs must be fully consistent with existing treaty obligations, including the Limited Test Ban Treaty (LTBT). In addition, it should state that U.S. studies indicate that it does not appear to be possible to carry out major excavation PNE projects without violating the LTBT. The Delegation should solicit Soviet views on how they plan to conduct PNE excavation projects without violating the provisions of the LTBT.

3. After presenting the above position on the LTBT issue, the Delegation should reiterate the position on excavation PNEs given in NSDM 287, with the exception of continuing to propose a 0.2 KT limit on the fission yield of each excavation PNE device. In this context, the Delegation should:

(a) Reject the Soviet proposed gamma-mapping technique as inadequate for the determination of fission yield.

(b) Propose that the distance between any two explosives in an excavation salvo be limited to a distance greater than the emplacement depth of the deeper of the pair of explosives.

(c) Insist on the right of drillback to recover below-ground melt samples for any excavation event in which adequate above-ground samples are not available.

4. The basic means for yield verification of all PNEs should be national technical means (teleseismic and photographic) augmented by provisions for information exchange and on-site observers. Observers should have rights to verify independently the information exchanged. However, for events smaller than 50 kilotons, independent verification by observers of information exchanged is not required and the U.S. could forego the exchange of detailed geological information and detailed project descriptions.

5. The U.S. is willing to declare an intention to cooperate in the PNE field on the basis of reciprocity and mutual benefit, in ways consistent with applicable domestic laws. However, verification requirements for a PNE agreement pursuant to Article III of the TTBT must be worked out before proceeding to discuss specific arrangements for U.S./USSR PNE cooperation.

6. The President has decided that, in principle, the U.S. prefers a 150 KT limit on individual excavation PNEs and, in this context, would be willing to accept a one megaton limit on the aggregate yield of all salvos (contained and excavation) and forego the fission yield limit and associated melt samples verification technique for excavation PNEs. While this position is approved in substance, it should not be put forth by the Delegation until authorized by Washington.

Henry A. Kissinger

1. Summary: President Ford approved instructions for the U.S. delegation to the next round of the PNE negotiations in Moscow.

   Source: Ford Library, National Security Council, Institutional Files—NSDMs, Box 60, NSDM 297, Instructions for the U.S. Delegation to the PNE Negotiations, Moscow, 6/3/75. Secret. Copies were sent to Brown and Colby. NSDM 287 is Document 118. The Department transmitted the instructions in telegram 138355 to Moscow, June 13. (National Archives, RG 59, Central Foreign Policy File, D750206–0088) The third round of negotiations opened on June 3 and concluded on July 28. Summaries of the sessions are in telegrams 9830, July 14, and 10549, July 28, both from Moscow. (Ibid., D750242–1198 and D750259–1107)