491. Letter From Dillon to McElroy1

Dear Neil:
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In his letter of August 14, 1959, Deputy Secretary Gates forwarded to me a memorandum dated August 13, 1959 to you from the Joint Chiefs of Staff questioning the capability of a control system to detect and identify underwater nuclear explosions. As requested by Mr. Gates, I suggested to Dr. Kistiakowsky that his office undertake a technical assessment of this problem.

In his reply, a copy of which is enclosed, Dr. Kistiakowsky raises some questions with respect to the concern of the Joint Chiefs and suggests that the matter be reviewed within the Department of Defense.

With best wishes,


/s/ Douglas
Acting Secretary
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Memorandum From Kistiakowsky to Dillon

Dear Secretary Dillon:
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Thank you for your letter, dated August 18, 1959, suggesting that this office undertake an assessment of the problem of detecting underwater nuclear explosions. On the basis of the information at present available to me, I do not believe that it would be feasible for my office to undertake such an assessment at this time.

As indicated in Secretary Gates’ letter of 14 August to you, the Report of the Geneva Conference of Experts concluded that there was a “good probability of detecting nuclear explosions of one kiloton yield set off deep in the open ocean,” and that “the on-site inspection carried out by the international control organ…would be able to identify with good probability underwater nuclear explosions with a yield of one kiloton and above.” It is not clear from the memorandum for the Secretary of Defense from the Joint Chiefs of Staff, forwarded to you by Secretary Gates, what new information is available to question these conclusions. This capability is apparently questioned, at least in part, on the basis of limitations in the seismic method; however, it should be noted that the detection and identification of underwater tests would be based primarily upon the hydroacoustic method and the subsequent collection of radioactive debris. Although it is stated that techniques for the concealment of underwater explosions are feasible, there is no indication as to how this might be accomplished or the possible magnitude of the concealment.

If there is concern about this matter on behalf of the Department of Defense, it might be useful, as a first step, for an appropriate technical group within the Defense Department, such as AFTAC, to undertake a careful examination of those aspects of this problem which are raised by the Joint Chiefs of Staff. On the basis of such a technical study, it would be possible to determine whether there are reasons for questioning the conclusions of the Geneva Conference of Experts.


G.B. Kistiakowsky
  1. Source: Transmits letter from Kistiakowsky stating Geneva experts concluded that underwater tests could be detected. Secret. 2 pp. NARA, RG 59, Central Files, 700.5611/8–2559.