THE summit has come and gone without improving the prospects for strategic-arms control. No doubt the meeting was useful in allowing Ronald Reagan and Mikhail Gorbachev to become acquainted and size each other up. Each seemed to convince the other that he wanted better relations (on his terms). The world breathed a bit easier by reason of the civility of the talks and the promise of their continuance. But of substance there was not much. On strategic-arms control, President Reagan's Strategic Defense Initiative (SDI) remains a roadblock. During the meetings and since, Mr. Gorbachev repeated that sharp cuts in offensive weapons would be feasible, but only if coupled with constraints on SDI. And just as adamantly Reagan reasserted his determination to pursue his vision of a leakproof defensive shield that would free the world from the threat of nuclear weapons and make them obsolete.
Gorbachev's arguments that SDI would actually accelerate the building of offensive as well as defensive systems and would jeopardize the stability of deterrence fell on deaf ears. He might have cited in support a passage from Defense Secretary Caspar Weinberger's report to the President just before the summit. ``Even a probable territorial defense,'' Mr. Weinberger wrote, ``would require us to increase the number of our offensive forces and their ability to penetrate Soviet defenses to assure tha t our operational plans could be executed.'' But that would not have budged Mr. Reagan. His long suit is not analysis.
Does this mean that strategic-arms control is foreclosed under Reagan? Not necessarily. Sometimes he can be moved in other ways. As governor of California and as President, he has shifted his position when faced with concrete choices with clear political costs and benefits.
The best hope for breaking the stalemate would be to create such a situation. To do that, several things would have to contribute:
First, the Soviets would have to be prepared to work out a mutually beneficial agreement on offensive weapons, conditioned on resolving SDI. To do so, Gorbachev would have to abandon one-sided proposals about weapons covered and address US concerns about first-strike weapons like the SS-18 or its follow-ons. That would require major changes in Soviet negotiating approaches and probably readiness by Gorbachev to overrule his military. For the US to be equally forthcoming, Reagan would eithe r have to play a much more intensive role than is his practice or replace the defense leadership.
The second requisite would be to devise a formula specifying what activities would be permissible on SDI. Gorbachev has conceded that ``basic research'' cannot be monitored. Beyond that, his real concern should be to ensure that the United States could not eventually face the Soviets with the risk of a breakout by a rapid deployment of a defensive system, by denouncing the ABM Treaty. One safeguard would be to extend the period after denouncing it before any deployment could begin to fiv e years or more. In addition, it should be possible to agree on what testing would be allowable without moving into development or production. Scientists and experts critical of SDI might be able to help in clarifying where that line might be drawn.
Third, Congress should explicitly address the interpretation of the ABM Treaty. The ``broad'' reading recently espoused by the administration would virtually gut the treaty; it tortures its terms and flouts the interpretation given to the Senate in the ratification process and adopted by the executive branch for over a decade. To protect its own prerogatives, the Senate should insist that the treaty be applied as presented to it, and Congress should specify that no funds may be expended fo r any activities outlawed by the treaty as so construed.
Together these conditions might produce agreement for major stabilizing cuts in offensive weapons and for regulating the pursuit of SDI. What are the chances of meeting them during the rest of Reagan's term? They involve many imponderables. Gorbachev would have to want such agreement seriously enough and feel enough in charge to take on the military establishment. If he means to reform the domestic economy, he would probably be glad to constrain resources diverted to the military, but he will also have to confront the civilian establishment in carrying out reform. Whatever he may wish, taking on both may be too big a load for some while.
And in the US, the civilian leaders in defense will obviously do their best to block any such outcome. Yet, if a constructive agreement could be shown to be within grasp, public opinion in this country and abroad would probably exert substantial pressure to bring it about.
The President, faced with a concrete choice, might well be tempted. His desire to reduce the nuclear danger appears sincere. This would offer him the only real chance to do so during his tenure. And by allowing research and regulated testing, it would not foreclose the exploration of strategic defense, which is inevitably an issue for actual decision only many years ahead.
Robert R. Bowie has been concerned with foreign affairs for nearly 40 years on the Harvard faculty, in government posts, and as a consultant.