Foreign Relations of the United States, 1981–1988, Volume IV, Soviet Union, January 1983–March 1985

232. Letter From Secretary of Defense Weinberger to the President’s Assistant for National Security Affairs (McFarlane)¹

Washington, June 28, 1984

Dear Bud:

(C) I am very concerned with the accelerating search for ASAT arms control options that might serve as a basis for near-term discussions with the Soviets.² While we all have attempted to separate ASAT and SDI in public and Congressional fora, it is clear that they are linked, both technically and from the perspective of arms control options. The worst possible scenario I can imagine would be one that places the President in a position of destroying his own defensive initiative via arms control proposals. I understand that the Senior Arms Control Policy Group (SAC PG) is meeting on June 28th to review the progress of your directed study effort. As you deliberate, I urge that you carefully consider the following preliminary assessment of the impacts on SDI of the several principal options being considered. Other options also have important implications for our security and we will continue to work closely with your study efforts.

(S) The thrust of the approaches to an ASAT Treaty ranges from an Incidents in Space initiative, to a ban on high altitude ASAT interceptors, to a ban on all ASAT interceptors. Our basic concern is that distinctions between ASAT and SDI will not be capable of being maintained.

(S) While I assume efforts will continue to draft language that would not legally constrain SDI, I believe that constraints would result. For example, the negotiating process will likely lead to political pressures to make a U.S. proposal more comprehensive, and consequently, further restrict SDI. In addition, the greater danger is that it would likely create expectations in Congress that would result in significant reductions in the SDI program.

(S) The proposal currently being studied to ban testing of high-altitude ASAT interceptors provides an example of the problem. The distinction between an ASAT interceptor and kinetic energy weapons that are being examined in SDI would be difficult to make and sustain in a negotiation. Several of the kinetic energy weapons that we will be demonstrating will have the inherent capability to attack high-altitude satellites.

(C) If we were unable to demonstrate these kinetic energy weapons, the net effect would be to eliminate our ability to develop the technology for near-term boost phase and post-boost phase intercept systems and cripple our ability to develop midcourse defense systems. In addition, we would be unable to demonstrate the kinetic energy weapons that would be used to protect our space-based sensors systems from attack by enemy ASATs.

(C) I offer our services to assist you in evaluating the impact on SDI of the various ASAT arms control proposals. Initially, I believe our mutual interests would be served by having the SDI staff brief those involved in this process at State and on the NSC staff on exactly what we are attempting to accomplish with SDI. While we recognize the international political pressure which we all are under and will fully support the finally agreed to position, my larger concern is that we are about to get involved in a process that could turn on us. Even if we are successful in structuring an option that meets our requirements, we must anticipate counterproposals from the Soviets and urging from our own Congress that will expand the scope of negotiations to impact the President’s strategic initiative.³

Sincerely,

Cap

1. Source: Washington National Records Center, OSD Files: FRC 330–86–0048, USSR 388.3 (Jun–1984). Secret.
2. See Documents 227, 228, and 230.
3. Below his signature, Weinberger wrote: “Bud—This is simply to sum-up my oft repeated points!”