157. Letter From the Chairman of the Atomic Energy Commission (Seaborg) to President Kennedy0

Dear Mr. President: As you know, the Atomic Energy Commission is hopeful that it will be possible to negotiate and sign a nuclear test ban treaty that will appreciably slow down the arms race and at the same [Page 394] time not jeopardize national security. We are concerned, however, that certain aspects of the proposed treaty could, in our opinion, adversely affect that security.

Our major concerns arise from the obvious danger that, having signed the treaty and thus having forestalled our atmospheric test series, the Soviets will later abrogate it and again mount a secretly-prepared test series. Unfortunately, we have little or no capability of detecting preparations now, and, in our opinion, the anti-preparation measures visualized for the inspection system will not appreciably improve that capability. In view of the impossibility—so well expressed in your March 2nd speech1—of our maintaining any real state of readiness to test during a moratorium or treaty, a repetition of their 1961 action by the Soviets could result in their making an even larger and possibly a decisive step forward relative to our nuclear weapons capability.

In view of this danger, the Commission deeply regrets the apparent necessity of continuing the offer of a moratorium on testing below the 4.75 threshold, since—with all testing suspended immediately—our weapons development capability would soon deteriorate to a very low level and our response to a new Soviet series would be even less effective, and appreciably slower, than if it were possible to continue low level underground testing.

Also, we are concerned by the proposal that abolition of the 4.75 threshold be substituted for the moratorium and that testing at all levels be permanently forbidden by the treaty, thus perpetuating the restraints on our laboratories. Admittedly, this change, which would extend inspection below the 4.75 threshold, would be technically attractive if we could assume that inspection would be introduced much sooner than the draft treaty now requires, and if we must make the further assumption that a moratorium would not actually end as planned after the three-year period. However, on the much more likely assumption that the Soviets will not cooperate in drastically speeding up preparations for inspection, no inspection will be possible during most or all of the three-year period (which will start with treaty signature), so that little or no technical or security advantage would be gained by abolition of the threshold now.

The Commission therefore respectfully urges that the threshold be retained, since—even with the moratorium—we would have the possibility of testing below some threshold after the three-year period, whereas abolition of the threshold now would not only limit our future action, but—by its finality—would add to the immediate adverse psychological effect on our laboratories. Even if a resumption of low level underground testing is ultimately found to be undesirable or not feasible [Page 395] and we then concede abolition of the threshold, little or no practical advantage will have been lost by postponement of the decision to abolish the threshold.

Respectfully yours,

Glenn T. Seaborg
  1. Source: Kennedy Library, National Security Files, Departments and Agencies Series, ACDA, Disarmament, 18-Nation Committee, Geneva, March 62. Confidential.
  2. See Document 143.