Foreign Relations of the United States, 1969–1976, Volume E–14, Part 2, Documents on Arms Control and Nonproliferation, 1973–1976

32. Memorandum From Jan Lodal of the National Security Council Staff to Secretary of State Kissinger¹

Washington, March 12, 1974.

SUBJECT

• Nuclear Test Ban and Your Moscow Trip

Gromyko recently indicated to you Soviet interest in doing something on the test ban at the Summit (Tab A). This memorandum analyzes the possibilities in this area and recommends a course of action in your discussions with Brezhnev.

I. Options for Agreement

There are four types of agreement which could be reached on testing limitations beyond those in the Limited Test Ban Treaty (LTBT):

1. A Comprehensive Test Ban (CTB). We publicly continue to support a CTB but insist that on-site inspections are required for adequate verification. The Soviets say they are ready to agree to a CTB if verification is limited to national means. They have also said privately that a CTB would require adherence by all the nuclear powers before entering into force. Political and security concerns vis-à-vis the PRC probably play a large role in the real Soviet attitude toward the CTB.

A major unresolved issue is whether peaceful nuclear explosions (PNEs), which apparently are of great interest to the Soviets, should be banned in a CTB. If they are not banned or appropriately safeguarded—which may not be feasible—PNEs would constitute a gigantic loophole in a CTB.

2. A Threshold Test Ban (TTB). A TTB would ban underground tests above a specified seismic level, which we would attempt to set in accordance with U.S. seismic verification capabilities and the level of testing we wished to permit. While we have not opposed a TTB, we have pointed out the difficulties in setting the level and verifying compliance with that level (seismic signals are unpredictable and vary with direction), leading to perhaps unintentional violations which could increase international tension. The Soviets have supported a TTB only if it were combined with a moratorium of undefined duration on tests below the threshold, i.e., essentially a CTB with verification by national means.

3. A Quota Test Ban (QTB). A QTB, such as mentioned to you by Dobrynin, would limit the annual number of underground tests by each side. In this form it is unverifiable, as it is feasible to carry out a number of tests simultaneously; we have done this a number of times. Accordingly, a QTB would likely have to be expressed at least partly in terms of annual cumulative seismic magnitudes, forcing a choice between a few large explosions and a larger number of smaller explosions. This type of cumulative provision would place a premium on measures to reduce the seismic magnitude of tests, such as testing in soft soil or in cavities. This would be difficult to verify precisely. Neither the U.S. nor the USSR has publicly supported a QTB.

4. A Moratorium. A moratorium on underground tests could help create a favorable political atmosphere for test ban negotiations, at least between the U.S. and USSR. However, unless limited in duration, a moratorium might remove a sense of urgency to negotiate a test ban. As a moratorium would be verified only by national means, it would prejudice the possibility of negotiating additional conditions for verification. We have opposed pressures for a moratorium, which have arisen in recent years only from the Senate.

Given the complexities involved in negotiating verification provisions, threshold levels, and regulation of PNEs, any movement at the Summit would probably have to be limited either to a moratorium or to an agreement in principle on negotiation of a CTB, TTB or QTB. To facilitate broad adherence and enhance their value as non-proliferation measures, actual negotiation could take place under the umbrella of the CCD, as was done with the LTBT.

II. Key Issues

Political

The CTB is not as important a measure as it was fifteen years ago. This has decreased the political incentive to pursue it for its presumed political and arms control advantages. Both the SALT process and the NPT have preempted many of the positive functions anticipated for the CTB, including the role it could play in improving relations with the Soviets.

A key political question is the degree of, and motivation for, Soviet interest in further test limitations. The Soviets would value some such limitation as a significant reaffirmation of détente. However, it is probable that they would value such a limitation at least as much for its adverse impact on our relations with the PRC. The Chinese would probably interpret further test limitations as a step to increase pressure on them in an area where it is understood they could not go along in the near term. At the same time, the Soviets would likely want to continue some nuclear testing to avoid any psychological disadvantages vis-à-vis the PRC. This set of motivations would lead them to the posture we have seen: favoring a CTB only on condition of PRC adherence (a point which has been made implicitly in public and explicitly in private by Soviet officials) and favoring some partial limitation on underground testing (such as the QTB mentioned to you by Dobrynin).

The UK would probably go along with any further limitation, although full testing of the Super Antelope warhead and re-entry vehicle will require about two more years of testing, if the new government decides to proceed with the scheduled program. The QTB idea originated with the previous Labor Government, in 1968. The French would oppose any limitations in the near term.

The key near-nuclears who have avoided signing the NPT—Israel and India—would also avoid a CTB. India, the original champion of the CTB, has prepared the ground by becoming a champion of allowing PNEs in any CTB, a loophole which would allow it to maintain and in effect exercise its nuclear option.

Domestically, the initial reaction to any further testing limitation would be positive. Whether this persisted and whether the Senate would give its consent would depend on the degree of support by DOD and AEC and the effectiveness of the campaign Senator Jackson would undoubtedly mount. Adverse reaction to a TTB or a QTB would be much less than for a CTB. If the Soviets were anxious to achieve a CTB (there is no sign of this) and were thus willing to concede a provision for on-site inspections, this would greatly improve domestic reaction to a CTB.

Security

Major effects of testing limitations on the U.S. nuclear posture include:

—Under a CTB, we would have to forego developing new more efficient warheads for certain specific purposes, such as improved ABMs and MIRVs. Although it would generally be very unwise, we could choose to deploy untested warheads (as we did during the 1958–61 moratorium). The TTB and QTB would tend to protect these options.

—Under a CTB, the U.S. would not be able to develop small “clean” weapons. This option would be protected under a TTB and QTB. Under any type of test ban we would be able to proceed with modernization of our tactical stockpile (which involves the 8 inch and 155 Howitzer) since these weapons are already fully tested.

—Under a CTB, our uncertainties would be somewhat higher on the reliability of existing weapons and on hardening non-nuclear weapons system components to nuclear effects (though there are ways to stimulate most such effects). It would be possible to design around potential problem areas, at increased cost. A TTB or QTB would tend to avoid these disadvantages.

—Adverse impact of further test limitations on our weapons development would be mitigated by the nature of our primary effort in strategic R&D, which has been in the area of delivery systems as opposed to warhead design. This impact would be further reduced by the greater importance of accuracy over yield in most systems of interest and by the relatively small gains achieved and predicted in yield-to-weight ratios of weapons designs. Although accuracy is affected by RV shape (which is constrained by warhead size), all our new RVs have the high beta needed for high accuracy. Further accuracy improvements would be achieved by improvements in missile and RV guidance.

—A CTB—and less a TTB or a QTB—would force future weapons systems to be designed around existing warheads, but adverse effects are unlikely to be major. Tested weapons are already available for the B–1. [2 lines not declassified]

None of these three types of test bans would affect limits on MIRV throw weight which might be achieved in SALT. However, by tending to freeze warhead designs these bans would put an upper bound on the number of RVs which could be carried for a given amount of throw weight per missile and on the yield of each RV. This effect is likely to be significant only in connection with development of hard target counterforce MIRVs, as discussed below.

A CTB, TTB or QTB could be a useful complement to restraints on modernization which might be negotiated in SALT.

The NSSM 128 analysis showed that our strategic retaliatory capability (in terms of Soviet fatalities) is insensitive to a CTB through the 1970s. The analysis also indicated that the Soviet retaliatory capability would not be changed by a CTB. The same conclusions applied to a TTB and QTB.

For most flexible response options, further limitations would make no appreciable difference. However, if we wished to develop a major hard target counterforce option, a CTB—and probably a TTB—would be inhibiting. [5 lines not declassified]

The principal security advantage to a CTB or TTB which we had foreseen over the past few years was that it would severely limit Soviet development of relatively small, high-beta, hard-target MIRVs. Now, with the development of relatively small MIRVs for the SS–X–17 and 19, which could also be retrofitted on the SS–X–18, and with the SS–X–18 MIRV itself, the Soviets probably have a small enough warhead which, in increased numbers and together with improved accuracy, would give them a silo killer, even if not an optimal one.

A key problem in analyzing the effect of further test limitations on the Soviets is that, ever since the LTBT forced them to test underground, we have lost track of their progress in warhead R&D. However, a CTB, and less so a TTB or QTB, would retard or prevent high technology threats to the Minuteman force.

Verification

A key question regarding the CTB is whether we are prepared to drop our long standing insistence on on-site inspection. Dropping this requirement would undoubtedly be necessary if we were to convince the Soviets to agree to a CTB. On the other hand, if the Soviets were for some reason to press seriously for a CTB, which I don’t foresee, we would get some leverage for seeking their acceptance to on-site inspections.

Improvements in seismic techniques and in overhead reconnaissance have greatly increased our verification capabilities since the early CTB days (1958–63), but they are still not foolproof. Now long-range seismic means can detect and discriminate all but about two percent (about four per year) of those seismic events equivalent in seismic magnitude to a yield of over 5 KT in normal testing modes. In theory, by using special methods to decouple the explosion from the surrounding earth (such as cavities or soft soil) the limit might be as high as 50 KT, though the chance of detection by other means increases with yield. Scenarios have been proposed for cheating under a CTB (such as by hiding in an earthquake), but they appear impractical.

Clandestine testing can be successful below 5 KT. Tests in this range would be primarily involved in improvements in the tactical warheads and would have little strategic effect.

As noted above, a QTB would be difficult to verify, even if combined with cumulative limits on the seismic magnitudes of nuclear tests. Even further collateral constraints—such as preannouncement and solid information on the nature of the soil in which the test was conducted—would be needed for confident verification. We are unlikely to get such information from the Soviets.

Thus:

—A CTB cannot be verified with high confidence below a seismic magnitude of 4.5 (5–50 KT, depending on hardness of soil), but the strategic consequences of successful evasion below this level is not likely to be great. Furthermore, the Soviets could not conduct an extensive series of tests (such as would likely be needed for a significant departure in weapon design) with confidence of successful evasion.

—A TTB at 4.5 seismic magnitude (5–50 KT) can be verified with high confidence.

—A QTB would be difficult to verify precisely or confidently at any yields without collateral constraints.

Peaceful Nuclear Explosive Devices (PNEs)

Without safeguards, it would be possible to conduct clandestine nuclear weapons related testing in the course of PNE detonations. Safeguards on PNEs of a type already developed can be postulated, but such safeguards probably would be very difficult to negotiate; they would involve comprehensive international controls, substantial access to national territory by international inspectors, or the release of classified nuclear design information. Most such safeguards would not be acceptable even to the U.S.

If development of new types of PNEs is permitted, adequate safeguards would be nearly impossible to obtain. The testing for new PNEs would be completely indistinguishable from that required to develop new nuclear weapons. Thus, testing new PNEs would have to be treated identically to testing of new nuclear weapons—i.e., prohibited in a CTB, prohibited above the agreed threshold in a TTB, and counted under the quota in a QTB.

We do not know how much importance the Soviets attach to retaining their PNE capability under a CTB, but they have been pursuing their PNE program at a rate approximately three times that of the U.S.; they have announced that they have refined four applications to practical use. In the U.S., PNEs (the Plowshare Program) have not yet attained commercial applications, though the technology is available for several uses of economic potential. With the energy crisis, the possibility of using PNEs for extraction of shale oil is receiving much attention.

The Non-Proliferation Treaty requires nuclear powers to share the benefits of PNEs with non-nuclear weapons states (NNWS) once PNEs are economically practical. No such services have yet been provided. It is not known whether the NNWS would sacrifice PNEs to attain a CTB or insist that PNEs be accommodated under a CTB. If PNEs were prohibited, some near-nuclear states might refuse to join a CTB under this pretext (e.g., India). Others, however, might favor banning PNEs if they prove to be a basic impediment to a test ban.

Bureaucratic Situation

You have recently issued NSSM 195, which calls for an updating of the NSSM 128 study of nuclear test limitations. It should be finished by the end of April and would thus be useful in preparing for any further discussion of testing limitations at the Summit.

AEC, OSD and JCS strongly oppose a CTB as detrimental to our nuclear posture (including the viability of AEC labs) and as unverifiable at low yields. They oppose a TTB and QTB on similar grounds and because they view them as slippery slopes to a CTB. However, as both the TTB and QTB would permit some testing to continue, the opposition is less strong than for a CTB.

III. Conclusions and Recommendations

None of the further test limitations have overriding political or security advantages or disadvantages. However, any further limitation is likely to cause problems in our relations with the PRC.

A CTB would probably not be acceptable to the Soviets without Chinese participation. If it were acceptable, we would be forced to decide whether we were willing to forego the advantages of further testing for little identifiable security or political gain. We would have to drop our insistence on on-site inspections to get an agreement at our initiative. Negotiations would be complicated by the difficult issue of whether and how to permit PNEs.

A TTB would be difficult to negotiate and verify. It would have less advantages and disadvantages than a CTB. The PNE issue also arises for a TTB. A TTB would be somewhat more acceptable to the AEC, OSD and JCS than a CTB, as it would permit some testing to continue.

A QTB might be relatively meaningless unless the quota were set very low, in which case it approximates the advantages and disadvantages of a CTB. In any event, difficult problems of verification of the quota would remain. As with the TTB, a QTB would be somewhat more acceptable to the AEC, OSD and JCS than a CTB.

A moratorium would be useful only if there was the clear will and means on both sides to proceed quickly to an agreement.

To facilitate agreement on any of the above arrangements, they could be made of limited duration.

In sum, there is not much in it for us in any further testing limitations.

Based on the above, I recommend that you take no initiatives with Brezhnev on this issue. In response to an opening by Brezhnev, I recommend that you probe Soviet interest in a CTB, TTB, and QTB—with and without PRC and French participation—and in doing something for us to aid in verification if we were to agree to negotiate a CTB. You should emphasize the difficulty we would have in accepting a CTB without on-site inspections. If the Soviets appear malleable on on-site inspections, we would have to take the possibility of a CTB much more seriously. You should also probe Soviet willingness to forego PNEs, which would remain as a major obstacle to a CTB or TTB.

If for overriding political reasons, you feel it important that the U.S. take some initiative on this issue, I recommend suggesting a Threshold Test Ban (TTB) to Brezhnev. The TTB has less verification problems and less domestic opposition than other alternatives and would cause us less problems internationally. Nonetheless, as I believe the above analysis clearly demonstrates, the TTB, like the other alternatives, would be relatively meaningless in its contribution to national security. Nor would it receive significant support from domestic political elements pushing for a CTB. It must be understood for what it is—essentially a cosmetic agreement with little real significance.

Based on your decision, we will prepare appropriate talking points for your use with Brezhnev.

Agree with recommended approach; prepare talking points to respond to a possible opening by Brezhnev.

Prepare talking points outlining a U.S. proposal for a TTB.

Schedule meeting to discuss.

Hal Sonnenfeldt and Bill Hyland concur.

1. Summary: In advance of Kissinger’s trip to Moscow and discussions with Brezhnev, Lodal summarized four possible types of agreement on nuclear testing limits, highlighted several key issues, and offered a recommendation for an approach with Brezhnev.

   Source: Ford Library, National Security Adviser, NSC Program Analysis Staff Files, Convenience Files, Box 46, Test Ban Messages, 1974 (1). Secret; Eyes Only; Completely Outside the System. All brackets are in the original except those indicating text that remains classified. Tab A, an excerpt of a February 4 memorandum of conversation between Gromyko and Kissinger, is attached but not published. The memorandum of conversation is printed in full in Foreign Relations, 1969–1976, volume XV, Soviet Union, June 1972–August 1974, as Document 158. NSSM 128 is published ibid., volume E–2, Documents on Arms Control and Nonproliferation, as Document 303; a summary of the study in response to NSSM 128 is ibid., Document 313. NSSM 195 is Document 30 in this volume.