Office of the Historian

183. Memorandum From the Director of the Arms Control and Disarmament Agency (Iklé) to the President’s Assistant for National Security Affairs (Scowcroft)1

Washington, March 24, 1976.

SUBJECT

  • Threshold Test Ban Treaty

NSDM 256 of June 10, 1974, which spelled out the basic U.S. position for a threshold test ban, states that “the U.S. can accept a provision allowing for no more than two unintended and slight breaches of the threshold per year.” In October 1974, Ambassador Stoessel obtained an oral understanding regarding the interpretation of such “unintended and slight” breaches.

Until two months ago, I was unaware of this oral understanding; and to my knowledge, it had not come to the attention of the Verification Panel. We have since analyzed the implications of the understanding reached and sought to clarify its content with your staff (see attached Marcum/Rochlin memcon).

In my view this oral understanding is too loose. It could lead to serious difficulties in monitoring compliance and might well be subject to substantial Senate criticism during the ratification process. I therefore recommend that:

(1) We should formulate considerably tighter criteria on this issue than the October 1974 understanding, and

(2) We should go back to the Soviets and seek a formal commitment from them to abide by the same criteria.

From a tactical point of view, it seems to me these steps ought to be taken before we wind up the negotiations in Moscow on the PNE Agreement and the related TTB implementation.

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In the meantime, you might want to have Walter Stoessel alerted of this problem. ACDA will do everything it can to help expedite the on-going staff-level interagency study for working out tighter criteria.

Fred C. Iklé

  1. Summary: In light of uncertainties in the interpretation of the U.S. position on the Threshold Test Ban Treaty as stated in NSDM 256, Iklé recommended to Scowcroft two steps for consideration before the conclusion of PNE negotiations in Moscow.

    Source: Ford Library, National Security Adviser, Presidential Agency Files, Box 1, Arms Control and Disarmament Agency March 30, 1976–May 9, 1976. Secret; Exdis. Iklé signed “Fred Iklé” above his typed signature. The Marcum-Rochlin memorandum of conversation is not attached. In a May 4 letter to Scowcroft, Seamans, at Marcum’s request, stated ERDA’s position on a 150 kiloton yield design standard. (Ibid., Presidential Subject File, Box 15, Peaceful Nuclear Explosions Treaty (1)) NSDM 256 is Document 54. Stoessel’s October 1974 oral understanding with the Soviets was presumably reached during the first round of the PNE/TTBT negotiations in Moscow.

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