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

20. Memorandum From the Head of the Delegation to the Nuclear and Space Talks (Burt) to Secretary of State Baker¹

Washington, May 17, 1989

SUBJECT

• The Bush Approach to START

As we begin active interagency consideration of new START initiatives leading to NSC meetings in early June, I want to lay out for you my views on how we should put a Bush stamp on START.

The Current Situation

As I indicated when I briefed you² recently, our key task in START is to seek a good treaty that will avoid a regeneration of the anti-SALT II coalition, where those who opposed any arms control agreement were joined by moderates who objected to technical flaws in the Treaty. To prevent such an occurrence, we should focus on improving the current START framework in a way that will win the allegiance of the moderate center. This means generating an appealing theme and then devising proposals to give that theme real substance.

The Theme

Our theme should be reducing the risk of nuclear war, by promoting the evolution of more survivable and predictable force structures that lessen incentives to conduct a first strike. During the Reagan era, the public was often given the impression that the US sought to reduce nuclear arms as an end in itself. Thus, the theme of nuclear risk reduction will help to put a Bush stamp on START while returning the public focus to the proper objective.

In fleshing out this theme, we should ensure that our package of initiatives is more than cosmetic. Tinkering on the margins of our START position—as some in State want to do—will not give our new approach credibility. There are real opportunities to improve our position, in ways that would not only enhance our security, but which could also improve the chances for START ratification by responding directly to criticisms that have been directed at the existing START framework by influential experts.

A weighty package would also help the President politically, by demonstrating that this Administration is pursuing ambitious objectives, and not just, a “status quo-plus” policy, toward the Soviets.

Possible Initiatives

I briefed you on several possible START initiatives. Of these, there now appears to be a consensus within the Department in favor of the following:

— Dropping the Ban on Single-RV Mobile ICBMs: We should allow single-RV mobiles, to reflect the President’s decision on Midgetman and make START-mandated forces more stabilizing.

— MIRV Limit: We should replace our current proposal for an ICBM warhead sublimit (the utility of which is waning) with a limit on MIRVs—either a sublimit on MIRVed ballistic missile warheads or a limit on the ratio of ballistic missile warheads to ballistic missiles—to focus on deMIRVing as a key element of stabilizing reductions. I find the ratio approach more intriguing, but am concerned that its novelty may inhibit acceptance, both at home and by the Soviets.

— Short-Time-of-Flight SLBMs: We should propose to ban short-time-of-flight testing, if we can develop an unambiguous and verifiable provision. (As you know, the Soviets also suggested such an initiative at last week’s Ministerial.³)

Although these three options are desirable, I question whether they alone would provide us a package substantial enough to give our theme credibility. We can do better, by adding to the package a ban on MIRVed mobile ICBMs, if political considerations warrant it, and by approaching the Soviets quietly to seek additional constraints on heavy ICBMs.

A Ban on MIRVed Mobiles

Of all possible strategic systems, MIRVed mobiles provide probably the greatest opportunity for the Soviets to break out of START limits rapidly. [3 lines not declassified] With a START-permitted rail-mobile infrastructure, the Soviets could use illegal SS-24s on illegal launchers or as reloads for legal launchers, and each SS-24 would add 10 warheads to the Soviet force. Even with a MIRVed mobile ban, the Soviets would retain other breakout possibilities. But why not do what we can to limit breakout potential? A MIRVed mobile ban, by eliminating the infrastructure that supports the rail-mobile system, would make it substantially more difficult for the Soviets to prepare for and execute a breakout.

We should also recall that rail mobility is an area of inherent Soviet advantage. We expect the Soviets to deploy up to one-third of their trains out of garrison on a day-to-day basis to maintain survivability. Due to political problems, our trains are likely never to get out of garrison in peacetime, and some question whether they would disperse even in a crisis.

As for the concern that a MIRVed mobile ban would increase the number of SS-24s in silos, such an increase could be held down by the MIRV limit discussed above.

This said, the primary consideration is the political effect on the President’s ICBM modernization program. Clearly a MIRVed mobile ban makes no sense unless we are committed to a single-RV, road-mobile Midgetman in addition to a rebased MX. With the two-missile approach, a ban proposal could undercut support for MX rebasing by indicating the Administration is prepared to live without the rail-garrison mode, a shift from the judgment implicit in the President’s decision. On the other hand, if support for the ICBM program is waning, a ban proposal could shore it up by providing a bargaining chip rationale for MX.

I conclude that we should propose a MIRVed mobile ban, if we judge that such a proposal would be helpful in achieving the necessary support for our ICBM modernization program.

Heavy ICBMs

Constraints beyond the currently agreed 50% cut in Soviet heavy ICBMs—deeper cuts, testing and modernization limits, or a ban—would further limit the only missile the Soviets have today that is capable of destroying hard targets. And the SS–18 is becoming more capable as the Soviets modernize it.

Up to now, the Soviets have strongly resisted further SS–18 limits. Thus, a US proposal to this effect could require a high price or be seen as erecting an unnecessary barrier to progress. Yet several Sovietologists have told me the Soviets might be persuaded to reconsider, if approached quietly on the subject.

I believe there is much we could gain, and little to lose, by trying a quiet approach to the Soviets to gauge their flexibility on this question.

Conclusion

With a MIRVed mobile ban as an integral element, and supplemented by a quiet approach on heavies, our package would have real meat. It would fit well our theme of nuclear risk reduction and would respond to Congressional concerns about START’s effect on ICBM vulnerability and breakout potential.

If we judge that a MIRVed mobile ban would undercut our ICBM modernization program, the MIRV limit should be the centerpiece of our package. In that case, I would favor the more novel option, the warhead-to-missile ratio, as well as a proposal for future reductions in the ratio to encourage further deMIRVing.

I understand that EUR agrees with the thrust of my recommendations and shares my view that the Soviets would be prepared to consider such proposals as steps that could improve the START package and make it more ratifiable.

1. Source: Department of State, Central Foreign Policy File, STARS, Document Number 89170489. Secret; Exdis.
2. Not further identified.
3. See Documents 17, 18, and 19.