Office of the Historian

450. Memorandum of Conversation1

USDel/MC/12
Washington, April 4, 1959, 3 p.m.
[Facsimile Page 1]

SUBJECT

  • Geneva Nuclear Test Negotiations

PARTICIPANTS

    • United Kingdom:
    • Mr. Selwyn Lloyd
    • Sir Harold Caccia
    • Sir William Penney
    • Mr. John Roper
    • Department of State:
    • Mr. Christian Herter
    • Amb. James J. Wadsworth
    • Mr. Philip J. Farley—S/AE
    • Mr. Ronald I. Spiers

Mr. Lloyd suggested that the discussion begin with a consideration of our position when the Geneva nuclear test negotiations resume April 13. Mr. Herter asked Sir William Penney to report on his impressions of the technical position he found in his discussion with U.S. scientists this week. Sir William said that the most important issue related to the possibilities of decoupling or concealment. He said that he had carefully reviewed the theoretical treatment of the U.S. scientists which be found accurate and “almost certainly right”. However, there were many uncertainties in geophysics and it was impossible to tell whether what was theoretically possible would be possible in practice. He strongly supported the idea of a testing program to check on the theoretical possibilities of decoupling as well as on improvements in instrumentation worked out by Berkner and his panel. He did not know whether nuclear tests should be part of this program or whether high explosive detonations would be sufficient. This was a question with many political implications.

Mr. Lloyd said that, as he understood it, it now appeared that there would be no certainty of detecting underground tests under 50 kilotons or more. Mr. Herter said that this brought us to the problem of what our position would be if the Soviets dropped their veto demands, and whether there would be a sufficient deterrent to violation to make it possible for us to accept the agreement. Mr. Herter said that we had this afternoon despatched a letter from the President to Prime Minister Macmillan regarding our position on April 13, a copy of which be handed to Mr. Lloyd. After reading the letter Mr. Lloyd asked whether the [Facsimile Page 2] following sentence in the draft letter to Khrushchev was not somewhat disingenuous: “If you are prepared [Typeset Page 1626] to change your present position on the veto, on procedures for on-site inspection, and on early discussion of concrete measures for high altitude detection, we can of course proceed promptly to conclude negotiation of a comprehensive agreement for suspension of nuclear weapons tests.” Mr. Herter said that if the USSR were to change its position on the points cited, the U.S. would be willing to negotiate an agreement on the cessation of all tests. We had never thought a foolproof agreement possible. What we were seeking to create was a level of risk for the potential violator sufficient to deter him from violating. He pointed out that we were now, under the terms of the Annex we had proposed in Geneva, prepared to accept inspection of 20 per cent of the underground tests below 5 kilotons. This was a concrete example of the approach of deterrence. Mr. Lloyd said that he considered this a quite adequate level for deterrence. Mr. William Penney and Amb. Caccia thought the general approach presented in the letter to Macmillan was excellent.

Mr. Herter then handed Mr. Lloyd copies of a draft statement to be made by Amb. Wadsworth at the opening meeting. He explained that this statement had not been fully cleared within the U.S. Government, but that it would be useful to the British in understanding the approach we suggest.

Sir William Penney said that in his view the basic question to be answered if this approach were taken was whether we would resume underground testing. If this was the case the position might be difficult to put across, since it would be pictured as a stratagem intended to permit continued weapons testing. Mr. Herter said that we would certainly not resume underground testing before October 31. Sir William suggested that the Soviets would also claim that there needed to be no further controls than those already in existence if the agreement were limited to atmospheric tests. A final technical question which would need to be resolved would be the definition of the upper limit of the atmosphere. He was satisfied with the American position of using the 50 kilometer figure set forth in the Genova experts’ report, but felt it would be necessary also to state that we would do no extra-atmospheric testing while we were working out the control schemes.

Mr. Lloyd stated that the British would give careful study to the American suggestions and respond promptly.

  1. Source: Nuclear test suspension negotiations. Secret; Limit Distribution. 2 pp. NARA, RG 59, Secretary’s Memoranda of Conversation: Lot 64 D 199.↩