Western defense -- and `star wars'

IS the SDI program at last going to get some much-needed scrutiny from Congress? Recently, 46 senators wrote a letter about the program to the chairman of the Senate Armed Services Committee. Specifically, they urged that the Strategic Defense Initiative (SDI) appropriation for 1987 be limited to $3.1 billion instead of the $5.4 billion President Reagan requested, providing a real increase over 1986 of 3 percent instead of 77 percent. While favoring a vigorous research program, they were worried about the impact of the requested SDI funding on other military needs, especially readiness and conventional forces. But they also expressed broader concern over the unclear goals of the SDI program, its excessive speed and unrealistic schedules, and its relation to the 1972 ABM Treaty.

These concerns are well founded. The program is marred by serious confusions which Congress should insist on clarifying.

Objectives: The President continues to reaffirm the vision of his March 1983 speech of a leakproof shield that would end reliance on deterrence based on the threat of retaliation and make nuclear weapons impotent and obsolete. Few others believe this vision feasible, both because of the inherent technical difficulties and because no responsible leader would entrust the nation's security solely to a complex defense system that could never be tested under realistic conditions.

Criteria: Assuming some ballistic defense proves feasible, what criteria should be used in judging whether to deploy it? Here again there is confusion in the administration. At first it endorsed guidelines proposed by arms negotiator Paul Nitze, which said SDI would be worth deploying only if survivable and cost effective. In other words, if it would be more costly for the Soviets to knock it out or counter it or swamp it with additional missiles than it would be for the United States to expand the defenses. These are sensible but stringent criteria. Recently backers, including Gen. James Abrahamson, the program director, have proposed that the key test should be ``affordability'' instead of cost effectiveness. Obviously that opens the door wide for the standard line: ``We can afford whatever we need for security.''

If SDI is a means for enhancing deterrence, then it must be judged in comparison with other means to that end, such as putting more missiles at sea, or reducing the vulnerability of land-based missiles by making them mobile, or making them less profitable targets by having single warheads instead of MIRVs. That was the basis of the proposal of the Scowcroft Commission for the small, mobile Midgetman missiles. That was approved by the President, but the Pentagon, which prefers larger, more complex missiles, has engaged in foot dragging and ``reappraisals.'' Incredibly, a ban on mobile missiles was included in the latest US arms control proposals -- surely a new high in cross-purposes.

Arms control: SDI intersects with arms control in two ways. One is its relation to the 1972 ABM Treaty, which outlaws developing, testing, or deploying any space-based system (though not research). The President has asserted that SDI would be only a research program compatible with the ABM Treaty. (The Soviets have been doing such research for some years). But this, too, has been muddied. Some months ago, at the behest of the Pentagon, the administration ``reinterpreted'' the ABM Treaty so as virtually to gut its explicit constraints on testing and developing an SDI-type system. But then Secretary of State George Shultz forced some backpedaling by stating that in practice the US would still conform to the more restrictive original interpretation. That, of course, leaves the issue unsettled.

The SDI is also involved in any control of offensive weapons. The Soviets will hardly agree to any major constraints on such weapons while facing uncertain possibilities regarding SDI. Indeed, the President's speech launching the SDI recognized an inherent linkage. Yet, the President so far has rejected any regulation of SDI as part of the arms control negotiations.

These confusions and ambiguities about SDI are too consequential to be left unresolved. They can distort our own military programs, provoke Soviet worst-case reactions, and erode strategic stability. SDI cannot be dealt with in isolation. It must be fitted into the context of our interest in maintaining a regime that minimizes the risk of nuclear war while preserving Western security.

Congress has an obligation to insist that the administration show how the SDI program fits into such a regime, and to clarify its objectives, criteria, plans for SDI, and its relation to efforts for arms control. That is an urgent task worthy of Sens. Barry Goldwater and Sam Nunn, the ranking members of the Armed Services Committee, who have shown their deep concern for the strategic aspects of our military policies and programs.

Robert R. Bowie has been concerned with foreign affairs for nearly 40 years on the Harvard faculty, in government posts, and as a consultant.

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