Foreign Relations of the United States, 1961–1963, Volumes VII, VIII, IX, Arms Control; National Security Policy; Foreign Economic Policy, Microfiche Supplement

188. Message from President Kennedy to Macmillan, June 21¹

June 21, 1963

You will have heard that we have evidence of a second suspicious event in the Semipalatinsk area. While our people are still reviewing the evidence, it is hard to avoid the conclusion that we face an increasingly high probability that Khrushchev has ordered low-yield atmospheric tests. This probability faces us with a problem in preparing for the Hailsham-Harriman mission, and I would value your comments. If further studies or further evidence confirm the present probability, it will be hard for us to avoid a public statement, and indeed our hand may be forced at any time by leaks. Moreover, there is a question whether we should not say something to the Russians on this matter. We might look quite foolish if we should send Hailsham and Harriman without any public statement or private communication on these matters, in the light of these probabilities.

In a most tentative way, two possibilities have been suggested here: the first is that we might put out a quite low temperature statement in which we might tacitly accept possible tests at these low yields as parallel in a measure to our own underground testing. The second is that we might equally quietly suggest to Khrushchev that if he would agree to defer these events, we could make a similar arrangement with underground testing for a limited period. The first alternative has the disadvantage of seeming to sanction atmospheric testing. The disadvantage of the second is that it implies something like the old unpoliced moratorium, which is discredited here. I have not made up my own mind between these courses, and I am hoping that some better idea may emerge.

Meanwhile, we shall be discussing this question Saturday morning here before my departure, and if you have any suggestions I should be very grateful if I might have them before three o’clock your time.

1. Notes second suspicious event in Semipalatinsk area and invites Macmillan’s comments on Hailsham–Harriman mission. Top Secret. 2 pp. Kennedy Library, National Security Files, Departments and Agencies Series, ACDA, Test Ban Correspondence, 3/63–6/63.