Foreign Relations of the United States, 1989–1992, Volume XXXI, START I, 1989–1991

22. Information Memorandum From the Director of the Policy Planning Staff (Ross) to Secretary of State Baker¹

Washington, May 22, 1989

SUBJECT

• Promoting Bipartisan Support for our START Approach

SUMMARY: Putting the Bush Administration’s START effort on a firm foundation—one that will not only give our approach a promising send-off when the talks resume in mid-June but will also help pave the way for eventual ratification—depends on gaining sustainable, bipartisan support for an ICBM modernization program and a START negotiating position (particularly on mobile ICBMs) that are mutually reinforcing. Over the next few weeks, the Administration should initiate intensive, senior-level consultations with key Congressional players aimed at achieving such wide support. END SUMMARY

The NSC-led review process is now preparing the way for a series of NSC meetings beginning the week of June 5 that will determine our START positions. Within State, there is broad consensus on several additions/modifications to the existing U.S. approach that would put a distinct and positive Bush imprint on our new posture. However, a few initiatives are controversial within the building, and you will need to be involved in determining State positions. I understand Reggie will soon be forwarding material to you on where we stand.

Here I’d like to focus on one of the candidate initiatives—a ban on MIRVed mobile ICBMs—both because it will likely be the toughest START issue the President will have to decide in coming weeks and because it is crucially related to our ICBM modernization program. In light of the President’s decision to pursue rail-garrison MX as well as mobile basing for the Small ICBM, moving from our current proposal to ban all mobile ICBMs to a position permitting at least single-warhead mobiles should be a relatively easy decision (although OSD may object). The harder issue will be whether to permit or seek to ban MIRVed mobile ICBMs, the Soviet SS–24 and our rail-garrison MX.

Proponents of such a ban point out that the rail-based SS–24 is hard to verify and that the Soviets would have 10 extra warheads for each clandestine missile. Opponents note that a ban, even if negotiable, would result in additional deployment of less stabilizing silo-based SS–24s and that the Soviets, having already begun to deploy rail-mobile SS–24s, would be unlikely to accept a MIRVed mobile ban.

The strategic/technical arguments for and against a MIRVed mobile ban (summarized briefly in the attached sheet) strike me as fairly closely balanced. What should be decisive is the impact of our mobile ICBM negotiating position on our efforts to achieve the necessary domestic political support for ICBM modernization. After all, without a sustainable modernization program, the benefits of START and prospects for its ratification would both be sharply reduced.

The problem is that it is hard, in the absence of active consultations, to know how a proposal to ban MIRVed mobile ICBMs would play domestically. On the one hand, it’s argued that such a proposal would shore up support for modernization. This is based on the assumption that Democratic support for MX rail-garrison is very uncertain and could be strengthened by giving the program a bargaining chip rationale. Reportedly Nunn and other key Democrats favor a MIRVed mobile ban.

On the other hand, it’s argued that a ban proposal, by showing the Administration considers rail-mobile MX to be dispensable and useful primarily as a bargaining chip, could cause the coalition needed to sustain the two-missile compromise to fall apart. MX proponents (in the Air Force and on the Hill) could withdraw their already lukewarm support for the Small ICBM, and the whole thing could unravel.

On something so crucial to prospects for both ICBM modernization and START ratification, we should not make a decision on the MIRVed mobile ban based on guesswork and then simply let the chips fall where they may. Instead, we should actively seek—through high-level consultations during the next few weeks with key Congressional leaders—to put together a strong coalition supportive of our missile modernization package and our START position on mobiles.

We should let the requirements for building such a coalition drive our decision on MIRVed mobiles. If a proposed ban would be instrumental in forging a consensus, we should adopt that position. But if it would be harmful or not a significant factor, then I do not believe the case for a ban is strong enough to warrant going forward with it.

If the Administration wishes to pursue a strategy involving extensive consultations with the Congress (with both State and Defense playing leading roles), it would have to get started very soon. If you consider the idea worth pursuing, I will set up a meeting for you to discuss it with key people in State.

Attachment

Paper Prepared in the Department of State²

Washington, undated

Arguments Pro and Con a Ban on MIRVed Mobile ICBMs

Pro

— Every clandestine SS–24 would represent 10 additional warheads. It’s considered harder to detect clandestinely deployed rail mobiles than road mobiles. (A MIRVed mobile ban would be coupled with a ban on all rail mobiles.)

— Without a ban, legal non-deployed SS–24s (spares for testing, training, and maintenance) could be used as reloads for legal rail-mobile launchers.

— A U.S. system of debatable strategic merit (MX rail garrison would be vulnerable without hours of warning and would require politically tough dispersal decisions) would be traded for an already-deployed Soviet system with few political constraints on out-of-garrison operations.

— A ban would reinforce the de-MIRVing theme (although, banning a kind of mobile ICBMs, which are in principle stabilizing, would send an ambiguous signal in this regard).

— Acceptance by the Soviets cannot be ruled out; they probably don’t plan to deploy more than 40–70 mobile SS–24s.

Con

— A START position banning MIRVed mobiles could appear inconsistent with our modernization program, which gives priority to rail-garrison MX.

— Even under a ban, Soviet retention of silo-based SS–24s would entitle them to a substantial number of spare missiles which, in a crisis, could be deployed on illegal rail launchers (whose production or storage would be hard to detect).

— Under a ban, SS–24s that would have gone on rails would be deployed in silos, a less stabilizing mode (although a new sublimit on MIRVed missile warheads could bound this problem).

— While Soviet acceptance cannot be ruled out, it is unlikely. Mobile SS–24 deployments are already well along and will be a mainstay of Soviet survivability efforts.

— Until perhaps the late 1990s, mobile SS–24s will be less accurate and thus less threatening than silo-based SS–24s.

— With a ban on mobile MX, we could not field a mobile ICBM for at least another 3–5 years. Continued uncertainty about the fate of U.S. mobiles could harm ratification.

— A MIRVed mobile ban could make it politically (although not legally) impossible to put our MX back in silos later.

1. Source: Department of State, Central Foreign Policy File, STARS, Document Number 89170489. Secret; Exdis. Drafted by Einhorn; cleared by Burt and Timbie.
2. Secret.