Foreign Relations of the United States, 1977–1980, Volume XXVI, Arms Control and Nonproliferation

490. Memorandum from Secretary of Defense Brown to President Carter¹

Washington, May 15, 1978

SUBJECT

• Fissionable Material Cutoff

I believe that to make a US initiative at the SSOD urging fissionable material cutoff would be a mistake. It would introduce additional uncertainties into our own planning, particularly those for air-launched (and other) cruise missiles, Trident II, and M–X. In order to cope with our military needs, as well as with the (correct) perceptions that the Soviets are and will remain ahead in throw weight and in capabilities of their peripheral attack systems, we need to preserve our advantage in strategic warheads. This will not be easy in any event. But particularly because we can have more warheads while the Soviets have more throw weight only if our warheads are smaller than theirs, we will have to use more fissionable material per warhead.

The absence of a reasonable assurance of verification without intrusive control measures would make a successful negotiation difficult, at the least. Moreover, proposals that rely on dubious verification measures undermine the whole concept of arms control.

Though the United States position has favored a fissionable material cutoff in principle for a long time, the situation, including the balance between the US and the Soviet Union, has changed very substantially since twenty or even ten years ago. What might then have been an arrangement freezing us into superiority is by no means any longer the case; indeed, we may, particularly in the light of verification problems, be freezing ourselves into a position of inferiority in availability of necessary fissionable material.

My own judgment would be that we should be prepared to listen sympathetically to proposals that others may make at the SSOD on this subject in principle, but we should not make any such proposal an important part of our position. Moreover, we should oppose proposals that negotiations on this subject should be initiated at this time on the grounds that there is already a full plate of arms control negotiations in train. If we did propose a cutoff, I think we will be subjecting ourselves to a great deal of internal conflict that would probably spill over into other, more important and more urgent, arms control issues.

I attach a memo stating the position of the JCS, which is similar to but goes beyond my own.²

Harold Brown

1. Source: Carter Library, National Security Affairs, Staff Material, Brzezinski Office File, Subject Chron File, Box 118, Special Session on Disarmament: 2–5/78. Secret.
2. Not attached.