196. Unsigned Memorandum to McNamara, July 161
SUBJECT
- Views of the Joint Chiefs of Staff on the Khrushchev Test Ban Proposal of 2 July 1963 (U)
1. In connection with Under Secretary Harriman’s visit to Moscow, and in view of Khrushchev’s speech in East Berlin on 2 July 1963, the Joint Chiefs of Staff have considered the desirability of a nuclear test ban treaty which prohibits tests in all environments except underground.
2. The Joint Chiefs of Staff previously concluded in JCSM–463–63, dated 22 June 1963, that a comprehensive test ban proposal which did not permit testing to continue below specified detection and identification thresholds and which did not provide adequate means of on-site verification, would not be compatible with national security. In the case of a limited test ban which permits underground testing, the requirement for on-site verification is no longer applicable. While there are definite limitations on detection and identification possibilities in the atmosphere, underwater, and outer space, any attempt to incorporate thresholds in a limited test ban treaty under which testing would be permitted would probably so complicate it as to make it impractical. In particular, such provisions could give rise to endless argument with limited possibilities of objective determination, and to a situation in which the Soviets could possibly test above the threshold without our being able to prove that an infraction had occurred. Accordingly, it is believed that the specification of detection and identification thresholds for a limited test ban should not now be undertaken, despite the fact that clandestine testing would be possible under these circumstances.
3. With such a treaty, violations would have to be verified by national means without entry into the Soviet Union. Consequently, the obtaining of convincing evidence sufficient to prove that a violation had occurred could be difficult. Even if the evidence of violation proved to be conclusive [Facsimile Page 2] in the opinion of the United States, a question of major importance would be how the United States could use such evidence to justify a decision to withdraw from the treaty. The recent US reaction to evidence of Soviet atmospheric tests in June 1963 illustrates the types of difficulties which can be expected in cases of suspected violations [Typeset Page 536] of a limited test ban. Except in the event of a flagrant violation, a degree of ambiguity probably will always exist.
4. With these considerations in mind, the Joint Chiefs of Staff have developed the following criteria to evaluate from a military point of view a limited test ban which would prohibit testing in all environments except underground:
a. Abstention by the United States from all testing except underground must have no significantly adverse effect upon the relative military strength of the United States and the USSR. In this respect, the USSR must not possess an advantage of significant military importance in nuclear technology at the time of treaty ratification.
b. Progress which the USSR might make through clandestine testing in the atmosphere, underwater, and in outer space should have no significantly adverse effort upon the relative military strength of the United States and the USSR.
c. US underground testing must proceed at a rate which will insure continued progress in nuclear technology in order that the United States might maintain or improve its capability relative to the USSR.
d. US readiness to test in the atmosphere must be maintained in order that the United States might react quickly should the Soviets resume such testing or should the United States wish to withdraw from the treaty if its continued application should be judged contrary to the national interest.
e. Reasonable evidence available to the US Government of testing in the atmosphere, underwater, or in space will be accepted as prima-facie evidence of a treaty violation and the United States must be willing to withdraw from the treaty on the basis of such evidence.
f. Procedures for withdrawal from the treaty should be uncomplicated and capable of execution without undue delay.
5. Having established these criteria, the Joint Chiefs of Staff have applied them in the evaluation of a treaty of the type which Khrushchev appears to have proposed. They note first that the United States, under the proposed treaty, would be denied important testing in the following areas:
a. Very high-yield (10–100 MT) technology.
b. Certain nuclear effects phenomena, including electromagnetic (EM) pulse, related to the survivability of hardened dispersed fixed-based missiles.
c. The reliability of penetration systems.
d. The design criteria and reliability of highly effective and economical ballistic missile defense systems.
e. Tactical nuclear weapons effects.
The United States would also be deprived of the ability to use standardized tactical nuclear weapons for training exercises and development of effective tactics and techniques.
6. The USSR, on the other hand, even with no cheating, would incur fewer disadvantages than the United States under the proposed [Typeset Page 537] limited test ban. Because of previous experience, the USSR may not need to test in these nuclear effects areas requiring atmospheric testing to the same degree as the United States. Specifically, in the fields of very high-yield (10–100 MT) technology, medium-yield ground and KM pulse effects, and ballistic missile penetration and defense systems, the Soviets probably possess knowledge not yet required by the United States.
7. In addition, the USSR could further effect possible disadvantages of the treaty by clandestine testing, although at same risk of detection. Specifically, it is estimated that the Soviets could conduct tests of the following kinds with a reasonable confidence that their violation would be unnoticed or, if suspected, could not be proved adequately to provide a basis for abregation of the treaty:
a. Occasional tests at altitudes between 10 to 50 KM at yields up to 20 KT over remote regions of the southern hemisphere.
[Facsimile Page 4]b. Low altitude atmospheric tests up to 5 MT up to 10 MT altitude.
c. Underwater tests at kiloton yield.
d. An occasional very high-yield test in outer space.
8. As a result, if the Soviets were to exploit to the fullest extent the opportunities for clandestine testing in all environments, they could make progress unmatched by the United States in the fields of:
a. Very high-yield technology (10–100 MT).
b. Ballistic missile defense and penetration effects.
c. Subkiloton tactical weapons effects.
d. ASW effects.
e. Military training exercises with standardized small-yield weapons.
f. Increased confidence that stockpiled weapons will meet expectations in the combat environment.
Accordingly, the judgment of the Joint Chiefs of Staff is that there is reasonable doubt that the proposed treaty would meet either criterion 4 a or 4 b, above.
9. Both the United States and the USSR could conduct much important testing underground. However, progress in nuclear weapons technology will probably become, in time, more dependent upon integrated tests in which the relationship between the weapon design and the effects in the combat environment is investigated. Consequently, the pressure to supplement underground testing with an occasional system test in the combat environment will probably increase. Unless the United States is able to select and use a test site where megaton yield devices could be detonated underground, under the proposed limited agreement, it would be restricted in achieving significant improvements in high-yield (up to 10 MT) weapons and in conducting critical effects tests bearing on survivability of hardened facilities.
[Typeset Page 538]10. In light of the foregoing, the Joint Chiefs of Staff conclude that:
[Facsimile Page 5]a. The United States would have an initial advantage in underground testing because of more experience in this environment than the USSR. Continued underground testing at a sufficient rate could keep the weapons laboratories active, retain key scientific personnel, and provide progress in some areas of nuclear weapons technology.
b. A limited test ban treaty of the type considered has fewer objectional features and entails fewer risks than the comprehensive test ban treaty now under consideration upon which the Joint Chiefs of Staff last commented in JCSM–449–63, dated 13 June 1963.
c. Nevertheless, there are significant military disadvantages to the proposed treaty. To a degree difficult to establish, it could continue the USSR lead in very high-yield technology. In addition, there are significant opportunities for cheating which, if exploited, could provide military gains to the Soviets that would be denied to the United States. The test ban would deny the United States the opportunity to conduct important atmospheric effects tests and to eliminate some uncertainties in the survivability of our hardened, fixed-based second-strike force and to conduct training exercises with tactical nuclear weapons.
d. Unless the Soviets flagrantly violate the treaty, it is probable that withdrawal or abrogation would be made difficult by the need for the following:
(1) Sufficiently firm agreement among the US experts that a violation had occurred to warrant acceptance of the fact and further action.
(2) Sufficiently clear and usable evidence to establish proof of violation before world opinion.
(3) Sufficient proof of the security impact to warrant withdrawal from the treaty despite friendly and neutral pressure to overlook violations.
11. In summary, it is the judgment of the Joint Chiefs of Staff that:
a. A limited test ban treaty similar to the type proposed by Khrushchev would be militarily disadvantageous.
[Facsimile Page 6]b. The precise extent of the military disadvantage is difficult to assess.
c. In view of the foregoing, there must be overriding nonmilitary considerations favoring such a treaty for it to be in the national interest.
For the Joint Chiefs of Staff:
- JCS views on the Khrushchev test ban proposal. Top Secret. 6 pp. Kennedy Library, National Security Files, Departments and Agencies Series, ACDA, Disarmament, Test Ban, U.S. Military View.↩