Foreign Relations of the United States, 1958–1960, Volume III, National Security Policy; Arms Control and Disarmament, Microfiche Supplement

521. Telegram 5562 to London¹

Washington, January 23, 1960, 3:57 p.m.

5562. Please deliver following to Selwyn Lloyd from the Secretary. Advise date time delivery.

QUOTE January 23, 1960

Dear Selwyn:

As Mr. Dillon mentioned to you in his letter of January 6, we have been exploring possibilities for advancing in the current Geneva negotiations on nuclear tests a threshold proposal based on seismic magnitudes. We have now completed our study of this approach from a technical standpoint, and our delegation in Geneva has been authorized to discuss some specific ideas and proposals with your people there.

I was glad to note from your letter of January 14 that you welcome the threshold idea at least to the extent that it permits us to go beyond an atmospheric treaty and to ban at least certain underground tests. I am glad, too, that you have no objection to a threshold set at the level of 4.75 since that is the level we have now chosen for consideration on the basis of our technical studies.

We, too, have been giving serious thought to the question of possible Soviet reactions to a threshold proposal. I believe, as you do, that they may well seek to extract maximum political advantage by charges that the West is seeking to put a costly inspection system in the Soviet Union for intelligence purposes and at the same time to continue a program of nuclear weapons development. Against this possibility, however, we have weighed the clear advantages of a move which represents an advance over our earlier proposal for an atmospheric treaty, which gives evidence of our willingness to agree to a test cessation in all areas that can be adequately monitored, and which offers a constructive way to by-pass existing disagreements between US and Soviet scientists on criteria and detection capabilities.

From the standpoint of world opinion, I think this new approach will point up more effectively than our earlier atmospheric proposal the idea that our purpose is not a limited treaty but a phased approach to a comprehensive treaty. I think if we emphasize the idea of progressively lowering the threshold through joint research we will be able to make this goal and the road by which we propose to achieve it somewhat clearer than we were able to do last April. Moreover, on purely technical grounds I think we are in a better public position to press for a phased treaty than we have been in the past. Both the report of the technical working group and Khrushchev’s recent admission before the Supreme Soviet that modern technical equipment cannot provide absolute certainty that all underground nuclear explosions can be detected should be helpful in this regard.

On the basis of such factors as these I have come to the conclusion that the Soviets would be unlikely to use the proposal as the pretext for a break, and even less likely that it would prove advantageous to them if they should do so. The idea of the phased treaty, beginning on an even more limited basis, has already been advanced, and the idea that we could not agree to any cessation of tests which could not be effectively controlled has been a cardinal point of our public position from the outset. If a new proposal combined these elements with constructive new suggestions for getting around present technical disagreements, I doubt the Soviets could readily turn this new phased treaty proposal to their advantage. The effect of our earlier phased treaty proposal was in fact to put pressure upon the Soviets to move in a constructive direction.

I have given earnest consideration to your suggestion that the proposal be accompanied by a moratorium for a limited period of underground tests below the threshold. Despite certain public relations advantages, I believe we would have something to lose by such an uncontrolled moratorium in terms of maintaining the principle that international undertakings in the field of disarmament must be adequately controlled. We might lose militarily as well, of course, since the Soviets would be able to test below the threshold in confidence that signal strengths would not permit inspection whatever warnings we might obtain by intelligence means.

You refer to the fact that we have already had an uncontrolled moratorium for over a year, and that two or three more years would under our present proposals be required before a control system can become fully operative. It is just this fact, that we have already been perhaps overly generous in conceding a test moratorium without effective control, that makes me feel further extensions or relaxations of our requirements for a moratorium would serve to weaken the essential principle of controlled agreements.

You refer to the question of a Soviet resumption of atmospheric testing in response to any resumption of underground tests by the western powers. I am inclined to think that this is unlikely, and that if the Soviets resumed atmospheric tests they would, whatever their excuses, bear the odium for pollution of the atmosphere. In any case the threshold proposal would not carry with it any announcement of resumption of underground tests. It would merely, in the spirit of the President’s announcement of December 28, involve a statement in response to Soviet inquiries that, in accordance with the principle that we cannot agree to a cessation of tests in environments which cannot be controlled, the U.S. would be free to resume testing below the threshold when its national security interests so dictated. I have discussed this matter with the President and find that he shares this view as to the way the matter should be handled.

You mention that as a result of the agreed technical report of last summer we probably would be prepared to include a ban on high altitude tests. I think our position there should be consistent with what we say about the underground ban, and with the proposal of the President last April. At that time we suggested an agreed suspension of nuclear weapons tests up to the greatest height to which effective controls can under present circumstances be extended. This formula would leave for discussion, in connection with treaty language on high altitude, the question of the extent of controls and corresponding obligations we would want to include in the initial phase.

I hope that we will be able to reach agreement on this course of action in the near future, since a new western initiative at Geneva would, I think, be particularly useful at this time. I should be glad to know your reaction to the threshold proposal in light of the specifics Ambassador Wadsworth will be presenting to Sir Michael.

With warmest personal regards,

Most sincerely,

Christian A. Herter  UNQUOTE

Herter

1. Source: Transmits letter from Herter to Lloyd on threshold proposal at nuclear test talks. Confidential. 6 pp. NARA, RG 59, Presidential Correspondence: Lot 66 D 204, U.K. Officials Correspondence with Secretary Herter.