Foreign Relations of the United States, 1969–1976, Volume XXXIII, SALT II, 1972–1980

238. Memorandum From the President’s Assistant for National Security Affairs (Brzezinski) to President Carter¹

Washington, May 12, 1979.

SUBJECT

• NSC Weekly Report #96

[Omitted here is information unrelated to SALT II.]

2. Alert

Soviets Still Seek Two New ICBMs in SALT?

You should be aware of the possibility that one of the critical issues presumably settled between Vance and Dobrynin (the test constraints to ensure only one new ICBM) may not be resolved. Moreover, the Soviets may attempt to use the pressure of the summit to wring a crucial technical concession from us that will permit them to build two and not just one new ICBM.

We have had intelligence that indicates that the Soviet Union is developing a new lighter missile to replace the aging SS–11s. All the negotiations on new ICBM parameters seemed aimed at permitting just such a development in addition to developing another new MIRV missile under the ICBM exception in the agreement.

They finally accepted our position that anything that varied more than ±5% would be considered a new missile, but with one qualification: the Soviets want to be able to test a missile with a payload and launch weight significantly lighter than the existing missiles. We have agreed to this on the theory that if the Soviets want to offload warheads on an existing missile and still hit Kamchatka, they could reduce launch weight by offloading fuel. However, it is not at all clear that the Soviets have agreed that the weight reductions will be due to offloading fuel. Indeed the position, tabled in Geneva after Cy and Dobrynin presumably reached agreement, does not specify fuel offloading. If we fail to specify this point, then the Soviets can simply use this qualification to develop the new lighter single warhead missile they have planned all along.²

I believe we should brace ourselves for the possibility that the Soviets will try to roll us over on this technical issue in the final days before the summit.

This would be fully consistent with their negotiating strategy in SALT I where they sought at the last minute and obtained from Nixon an increase of 15% in diameter and depth of ICBM silos which permitted them to deploy a whole new generation of ICBMs (the SS–17/19).

I also note that the Soviets did not announce that the major substantive SALT issues had been completed. Moreover, their announcement of the summit date and place described it as “tentative.”³ The Soviets apparently may not appreciate the fact that if the SALT agreement permits them to build two new missiles it may well not be ratified by the Senate.

1. Source: Carter Library, Plains File, Subject File, Box 29, NSC Weekly Reports, 4–9, 1979. Top Secret; Codeword. Sent for information.
2. Carter wrote “We should head this off now—You & Cy advise” in the margin next to this paragraph.
3. On May 10, Vance announced at the White House that he and Dobrynin had concluded their negotiations on the remaining issues and the U.S. and Soviet SALT Delegations in Geneva had been instructed to incorporate those agreements into the Joint Draft Text. He also announced that the time and location for a summit were under discussion. Brown also made a statement endorsing the agreement. For the text of both Vance’s and Brown’s statements, see the Department of State Bulletin, June 1979, p. 23. The next day, Soviet news agency TASS also reported the agreement and announced that the summit was “tentatively” set for June 15–18 in Vienna. (The New York Times, May 13, 1979, p. E1)