Foreign Relations of the United States, 1969–1976, Volume XXXII, SALT I, 1969–1972

268. Memorandum From Secretary of Defense Laird to the President’s Assistant for National Security Affairs (Kissinger)¹

Washington, April 25, 1972.

SUBJECT

• Radar Controls for ICBM Defense

NSDM–158² directed that the Modern ABM Radar Complex (MARC) concept be applied to ICBM defenses, and the Soviets have recently indicated receptivity toward this approach. However, in Paragraph 14, NSDM–158 anticipated U.S. movement to a combination of qualitative and quantitative constraints on such radars. I believe we should move in this direction now.

Although geographical limitations on the deployment of Soviet ICBM defenses contribute to reducing the degree of Soviet population coverage, I believe limitations on the quality of ICBM defense radars are also necessary to ensure against extensive population coverage from ABM deployments in some of the Soviet ICBM fields east of the Ural Mountains. This is especially important in view of the fact that the Soviets, if they accept MARCs in ICBM fields, will probably insist on a larger number of MARCs than was contemplated in NSDM–158. The Soviets would be permitted by our current MARC concept to emplace radars of any size they wish in these MARCs.

Movement on our part to qualitative and quantitative constraints on radars in ICBM fields would entail permitting radars at a larger number of aim points than would MARC controls. Such deployments of qualitatively constrained radars, however, would provide the reduced vulnerability of the radar base needed to support larger numbers of interceptors for ICBM defense than permitted by the Treaty, if such larger numbers should become necessary.

In short, a combination of qualitative and quantitative radar controls on ABM radars in ICBM fields has two main advantages over MARC controls. First the combination of qualitative and quantitative controls would better limit coverage of Soviet population by the ICBM defenses. Second, it would permit a better radar base for expansion of U.S. ICBM defenses.

For these reasons I urge that the Delegation be directed to carry out explorations of a combination of quantitative and qualitative controls on ABM radars for ICBM defense, as anticipated in Paragraph 14 of NSDM–158, and in addition, be authorized to carry out these explorations in the context of permitting up to 25 qualitatively constrained ABM radars in agreed ICBM deployment areas.

Melvin R. Laird

1. Source: Ford Library, Laird Papers, Box 26, SALT, Chronological File. Top Secret.
2. Document 243.