How Congress can make good use of the MX report

The report of the President's Commission on Strategic Forces (Scowcroft commission) has attempted a healing job in developing a plan to unify fragmented constituencies that exist today. The report tries to save face and save money while avoiding embarrassment for the United States at the bargaining table with the Soviets.

It offers an integrated plan, made up of three major elements that are, in its terms, inseparable:

* 100 MXs in Minuteman silos.

* Engineering design of a small single-warhead missile and the evaluation of a variety of potentially survivable basing modes for its deployment in the 1990 s.

* A transition to an arms-control position of ''equal levels of warheads of roughly equivalent yield''; and a move away from counting launchers, as was done in SALT I, SALT II, and currently in START.

It has two additional elements:

* Continuation of current strategic modernization programs.

* A program to resolve uncertainties about hardening silos and shelters.

The commission has emphasized that this is an integrated package and no element can be taken alone or eliminated. Arms control is an inseparable element of the report, and the commission urges that the US negotiating stance move toward the control of warheads rather than launchers. The report should have made clearer the essential premise that if the United States fails to conclude a satisfactory strategic arms-control treaty, it will not achieve adequate stability.

While small, single-warhead missiles, because they present less attractive targets than a larger, MIRVed missile, arguably move in the direction of stability, no deployment in the US could be open-ended and remain politically acceptable. Yet, without agreed constraints, there is no reason to believe that the Soviets would exercise unilateral restraint and build fewer warheads than needed to destroy all of the US missiles.

Perhaps we will find a solution to vulnerable basing by mobility, deception, shelter hardness, or some combination. But we have failed up to now, not because of lack of technical ingenuity, but because we are an open society and the secrecy and restrictions needed to conceal thousands of missiles is very difficult to obtain. On the other hand, a lower number of small missiles, limited by treaty, presents a more promising deployment task.

The commission's strongest argument for MX is related to arms control. It is not a military argument so much as one of perception. The report argues that program cancellation would indicate both to the Soviets and our allies that we lack resolve. Conversely, proceeding with MX, it argues, will put pressure on the Soviets to reach a more satisfactory START agreement.

In this way, the commission tries to reconcile the apparent inconsistency of reducing vulnerability by shifting away from MIRVed missiles to a small missile and, at the same time, deploying 100 larger, 10-warhead missiles in place of the Minuteman missile, whose largest version has only three. One commission member has stated that the MX, without the other elements of the Scowcroft report, was a ''dead end.''

How is a congressman going to provide assurance that by voting for 100 MXs now, the country will obtain the whole package plan and particularly the arms-control segment? For, as indicated, without the stability that an agreement provides, the new deployments may be useless at best, and destabilizing at worst , for the Soviets are likely to match and surpass whatever the US does.

This has not been an administration whose zeal for arms control is noteworthy. Even our European allies have demanded the assurance of a ''two-track'' system; of arms-control efforts accompanying deployment of intermediate-range nuclear weapons.

Congress could demand its two-track system in one of several ways. It could require, as part of the legislation, that before deployment funds can be released the President must certify, in a detailed report to Congress at periodic intervals, the nature of its good-faith efforts in START talks, and that despite such efforts substantial progress is not being made. This would not make the MX program hostage to the Soviets - quite the contrary, it would make whatever pressure on them that MX theoretically exerts quite concrete.

Or a similar device could be developed whereby Congress would approve increments of MX deployment, say 10 or 20 missiles at each certification, thus putting pressure on the Soviets to move swiftly to a mutually satisfactory treaty in order to keep the number of MX deployed as low as possible.

Or the submission of SALT II for ratification might be required as a trade-off for approval of the Scowcroft commission report. As unlikely as this is politically, it has the advantage of setting a framework for further negotiations. It would also serve to perpetuate the counting rules and verification procedures, and continue the Standing Consultative Committee to resolve ambiguities, all of which have no legal status in strategic arms limitation today, because the interim agreement expired and SALT II was never ratified.

What Congress should not do is to set out a specific arms-control position, however sound it may seem, as a prerequisite to the other elements of the Scowcroft report. The point is that Congress should find some device that locks in the arms-control element, and puts pressure on both US negotiators and the Soviets to reach satisfactory agreement. Congress should not be content with merely the hope that arms-control progress will evolve along the lines of the Scowcroft report.