344. Response to National Security Study Memorandum 1231


The Problem

NSSM 123,2 issued on April 17, 1971, requests a study be made of “US/UK Nuclear Relations,” with particular emphasis on:

—The extent to which we are already committed to assist the UK in improving its strategic nuclear force under existing agreements.

—The implications of US assistance to the British in their efforts to improve the capability of their present Polaris systems through the “Project Definition phase.”

—The long-run implications for the US of a deeper involvement in the UK effort to develop and deploy an improved Polaris system, including an assessment of British strategic objectives and a possible future UK request for MIRV technology.

The specific issue is to what extent the US should assist the United Kingdom in its efforts to develop and deploy an improved Polaris system, in particular the UK Super Antelope program for improving the hardness and penetration capability of the front end of the Polaris missile system. (While the US and UK cooperate in other areas of nuclear weapons technology, there are no issues in these areas requiring NSC consideration at this time.)

The UK has been concerned for some time about maintaining the viability of their Polaris system. The British have concentrated on the problem of penetrating Soviet ABM defenses and striking Moscow and have been chiefly concerned with improving their penetration capability and hardening their re-entry vehicles to nuclear effects. They have considered a number of alternative solutions and have at various times asked our advice and assistance in studying these alternatives.

US assistance to the UK in the field of atomic weapons has been continuous since 1958. A comprehensive interagency review of this cooperation was contained in a letter dated May 10, 1971, from AEC [Page 1018] Chairman Glenn Seaborg to The Honorable John Pastore, Chairman of the Joint Committee on Atomic Energy. A copy is attached as Enclosure 1.

Since 1963 cooperation has included the UK Polaris force. In recent years we have assisted the British in evaluating the hardness and vulnerability of their Polaris systems, provided them information on modifications to our Polaris systems, exchanged further information on penetration aids, and made available exposure space in US underground nuclear effects tests. US–UK Joint Working Groups (JOWOG’s) have been established to exchange information on these subjects.

In November 1970, the UK formally advised DOD that the British Ministers had approved work on Project Definition for the Super Antelope Polaris improvement program and requested US assistance in the matter.

On March 25, 1971, the Deputy Secretary of Defense provided the Assistant to the President for National Security Affairs a summary of UK Super Antelope programs and informed him of DOD’s intention, in response to the British request, to assist the UK in Project Definition. He pointed out, however, that the DOD commitment was made without prejudice to our freedom of action beyond that point, and that further assistance would have to be the subject of a future decision. See Enclosure 2. While no formal reply has been made to the UK letter, there have been a series of meetings with the British, including a conference at the Pentagon on April 26–28, 1971, which have elicited more details of the program and during which the British have been given no reason to believe that the requested assistance in Project Definition would not be forthcoming. US representatives have agreed to have a follow-on session in the UK in late July to provide answers to the questions raised.

Technical details are discussed further on, but essentially the British would like the benefit of US technology in the Antelope Program and assistance in the analysis and design critiques on their approach to re-entry vehicle and pen aid design, including possible use of US contractors. They also want continued access to US underground nuclear effects tests in order to expose UK hardware samples, and possibly the use of White Sands Proving Grounds for flight test of components.

Although the British have requested our assistance only in the Project Definition phase, it is likely that they would seek further US support of some kind in development, production, and testing, if they decide to proceed beyond Project Definition. It is possible that they might request assistance in matters relating to the post-Project Definition phase prior to a UK Ministerial decision to move beyond Project Definition.

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While it may be possible to decide the specific issues of continued cooperation with the British without prejudging broader policy issues they do raise fundamental questions of the relationship of the UK Super Antelope project to our own strategic objectives. For example, is it in the US interest to maintain the credibility of the UK Polaris deterrence? Is the design objective of Super Antelope consistent with the role of the UK Polaris force in the NATO strike Plans? Is our control of the initiation of nuclear war and its conduct diminished by such a program as Super Antelope?

In addition, cooperation with the British on Super Antelope raises questions affecting the US negotiating position at SALT and the viability of bilateral agreements with the USSR limiting strategic arms. The possibility at SALT of obtaining agreement on the issue of strategic arms transfers to third countries by a generalized statement of purpose, and the credibility of our declaration that we have no intention of circumventing an agreement through third countries could be undermined if collaboration of Super Antelope extended to production and testing.

Although the Geneva negotiations on a comprehensive nuclear test ban, in which the US and UK are participating, are not currently a factor in US–UK nuclear collaboration, a test ban agreement, if one is ever achieved, could affect plans for underground testing for Super Antelope at a future date.

Lastly, the UK request impinges on a complex set of multilateral relationships and how US interests are affected by the development of third country nuclear forces in Europe, and thus the direction of our future European nuclear policy. Our help at this time in Project Definition of Super Antelope will undoubtedly influence and solidify our later relationship with them in the nuclear field and possibly make it less likely that the British would choose, or would be able in the light of the prohibitions of the Atomic Energy Act and our 1958 agreement, as amended, to move toward European military nuclear cooperation, should the US at some time wish to encourage this.

  1. Source: National Archives, Nixon Presidential Materials, NSC Files, NSC Institutional Files (H-Files), Box H–182, National Security Study Memoranda, NSSM 123. Top Secret; Sensitive; Restricted Data. Sent to Irwin, Packard, Moorer, and Helms. Copies were sent to the Director, Arms Control and Disarmament Agency and Chairman, Atomic Energy Commission. A title page, table of contents, and the enclosures are not printed.
  2. Document 340.