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

78. Paper Prepared by the National Security Council Staff¹

Washington, undated.

The Limited Test Ban Treaty (LTBT) and Its Relation to (1) Negotiation of the Agreement on Peaceful Nuclear Explosions (PNE) Collateral to the Threshold Test Ban (TTB), and (2) Implementation of Article V of the Non-Proliferation Treaty (NPT)

Introduction

In order to have a criterion against which compliance can be measured, as well as for reasons of world health, the LTBT states its prohibition against venting explosions as a requirement that no radioactive debris from a nuclear explosion should cross the testing nation’s border. An ancillary effect of this proscription has been to preclude most excavation PNEs. Mainly because of Soviet interest in conducting such shots, there has been a debate over several years as to the wisdom of amending (or reinterpreting) the LTBT to allow de minimus radioactivity levels to cross borders for legitimate PNE applications as long as no health risk exists. Since the U.S. has had little interest in excavation PNEs, no policy toward an amendment of the LTBT has been formulated—instead we have (at an unhurried pace) conducted technical assessments of the benefits of excavation PNEs and the possibility of limiting fallout to low levels, and continued a technical dialogue with the Soviets and others on these subjects. The next bilateral talks are this November, and multilateral discussions are planned for next January.

Amending the LTBT

The possibility of limiting radioactive fallout from excavation PNEs to a low level seems good. The use of small fission triggers, appropriate burial depths, and cloud steering by winds aloft could reduce the dose received by those in neighboring countries to a few percent of international standards for acceptable exposure and the long-term global dose to very low values compared to the natural background. Although a verification system could, in principle, be devised to insure that such events were not clandestine weapons effects tests, there may be very difficult practical problems to achieving adequate verification.

The necessary amendment of LTBT to allow excavation PNEs would change the present statement that radioactive debris cannot be present outside the territorial limits of the testing State, to state instead that venting nuclear explosions must be for peaceful purposes and the radioactive release should be as small as technically feasible and represent no danger to human health (as defined by acceptable dose standards).

Successful amendment or “reinterpretation” of the LTBT requires approval by a majority of the parties (over 100) and all of the original adherents (U.S., UK, and USSR). Our approval of an amendment would require Senate agreement to ratification, but reinterpretation could be handled by Executive Order.

The Soviets have urged us informally to propose an amendment but have not been willing, thus far, to take that initiative themselves.

Advantages and Disadvantages to Amending the LTBT

On the assumption that the technical issues can be satisfactorily resolved, there are several other considerations that should be weighed in determining a U.S. policy toward possible amendment of the LTBT.

1. Our domestic PNE endeavor is a modest R&D program, but were we to see advantage to an enhanced effort with new applications for ourselves or for others, the LTBT could constrain some of our projects and amendment of the LTBT would serve our purposes.

2. Article V of the NPT requires that if practical applications of PNEs are developed by nuclear weapons States, such applications must be made available to all Parties on a nondiscriminatory basis. Although never tested by any persistent pursuit of such assistance by a non-nuclear weapon State (NNWS), we could be faced in the future with a legitimate request for PNE services. While we have no obligation to provide PNE services if we have not developed the particular application for ourselves, our unwillingness to provide PNE services if requested could be seen as a failure of Article V of the NPT, and could lend impetus and some legitimacy to indigenous development of PNEs by NNWS.

To avoid the risk of stimulating PNE development, and to serve our other nonproliferation objectives, we may want to provide PNE services. Since the current foreign interest while limited is predominantly in the excavation area, it would be inconsistent to refuse to agree to amend the LTBT to allow such projects. Amendment of the LTBT would clear away one of the obstacles to vigorous enforcement of Article V of the NPT.

3. In trying to negotiate the PNE agreement collateral to the TTB with the USSR, we may well have to approve excavation PNEs above the threshold with appropriate verification safeguards. It may be difficult for us successfully to conclude such negotiations sui generis, since the Soviets may well want to link all relevant agreements on excavation PNE’s in the negotiations, particularly the amendment of the LTBT. Moreover, willingness on our part to consider the LTBT question favorably may be a useful negotiating tool in obtaining agreement to the observation and verification procedures we consider necessary to enforce the TTB as well as to establish the precedent of on-site inspection.

The disadvantages of attempting to amend the LTBT are several:

1. The importance and influence of this international agreement, which represented a turning point in global nuclear relations, can only be diminished if it is altered in order to allow one of the activities it was established to prevent: the spread of radioactivity.

2. It is very questionable that we would succeed in gaining the approval of a majority of the LTBT parties for an amendment. There is no benefit for most of the States and many may withhold approval as a demonstration of displeasure with the limited nature of the TTB, or conversely, seek a commitment to a CTB as the quid pro quo for supporting the amendment of the LTBT to allow excavation PNEs. Opposition arguments would note that health risks might be small but would be borne by all whereas the benefits derived from the PNEs would accrue to few; that there would be a finite number of premature deaths and birth defects from radioactive release; and that limits stated only in terms of acceptable human dose opens the door to increasing the radioactive burden in the atmosphere and the oceans.

3. Congressional ratification is questionable, and if a relationship is perceived between the necessity to amend the LTBT and the successful negotiation of the TTBT, both may be defeated. Using “reinterpretation” rather than amendment to avoid congressional ratification probably is too costly politically.

4. A substantial campaign to defeat ratification can be expected by environmentalists, who may also succeed in requiring governmental submission of an environmental impact statement which is then subject to protracted court tests.

5. Our foreseeable interest in PNEs is minimal. At present our only motivation to amend the LTBT is to accommodate the Soviets. The cost of this action to us may not be commensurate with the value we might receive.

6. By legitimizing venting, we may remove the technical obstacle of underground testing from an LTBT adherent considering development of nuclear explosives.

7. The AEC enforces de facto radiation standards more stringent than the international standards, and the practicable levels proposed for an LTBT amendment may, therefore, not leave an acceptable margin of safety compared to our own standards.

1. Summary: The paper analyzed several issues related to the Limited Test Ban Treaty and discussed the advantages and disadvantages of amending the LTBT.

   Source: Ford Library, National Security Adviser, NSC Program Analysis Staff Files, Convenience Files, Box 45, Nuclear Testing (1). Secret. Attached as Tab B to Document 77.