Having just returned from Moscow as a member of a bipartisan Senate delegation, I am convinced that a basis exists for a mutually advantageous arms control agreement in Geneva. However, both President Reagan and General Secretary Mikhail Gorbachev will have to rise above their respective bureaucracies and set the stage for compromise. Without a clear commitment on both sides to success in Geneva, the negotiations that follow the November summit will be little more than an exercise in futility.

In Moscow I received the impression that Gorbachev is ready to conclude an arms control agreement so that he can turn his attention to pressing domestic problems. In what could be a promising approach to break the deadlock in Geneva, Gorbachev told us that "if the United States were prepared to discuss the question of preventing the militarization of space, it would then hear from the Soviet side the most radical proposals covering strategic arms and medium- range weapons." Although later he made this point in a less forthcoming manner, we ought to concentrate on the formulation that only requires a U.S. willingness to discuss the Strategic Defense Initiative. The president should make it clear that the United States is prepared to discuss limitations on SDI and then challenge the Soviets to table their "radical proposals" for reductions in offensive forces.

Such a scenario could set the stage for negotiations on the obvious bargain to be struck in Geneva: deep Soviet reductions in offensive weapons in exchange for restrictions on SDI. By approaching the negotiations in these terms, we would be following the formula for success that was used by President Nixon in 1972 to achieve the SALT I agreements in which a freeze on strategic offsive weapons was coupled with the ABM treaty.

Some, including former Secretary of State Henry Kissinger (Washington Post--"We Need Star Wars," Topic A, Sept. 8), believe that we should hold out for both radical reductions in Soviet offensive weapons and press ahead with SDI. I fear, however, that such an approach would not be negotiable, because it would not dispel the Soviet concern that SDI is intended as a protective shield behind which the United States would have a first-strike capability. And, in the absence of an agreement, which I believe is only possible by constraining SDI, the Soviets would develop their own countermeasures, including more offensive forces or their own SDI, or both. In the process, the arms race would continue in new and more perilous ways.

The idea of making our country invulnerable to attack is attractive, but it is more a dream for the distant future than a near-term reality. Supporters of the SDI have scorned the strategy of mutual deterrence based on the concept of assured retaliation in the event of attack. Uncomfortable as a policy based on the threat of mutual annihilation may be, abandonment of the concept in the mere hope of acquiring the means to achieve security based on a concept of mixed offenses and defenses makes no sense. It would be far wiser to continue to rely on the system of deterrence that has kept us from nuclear war for 40 years while urgently exploring ways to achieve greater security at sharply lower levels of weaponry.

It is not feasible for the president and Gorbachev to negotiate an agreement at the summit, but they could agree on principles to guide the negotiators. Here are proposals I believe that the president should be prepared to offer either immediately or at the summit:

*We should indicate to the Soviets that we are prepared to discuss a ban on weapons in space. We should make it clear that we intend to ensure that both sides have the leeway to continue a vigorous program of research on space defenses, but that we are willing to find a mutually acceptable point in the course from research to development, testing and deployment beyond which both sides would be obligated not to go for a fixed number of years.

*We should express a willingness to reaffirm our adherence to the ABM Treaty, which constitutes the crucial underpinning of mutual deterrence. In return, we should insist that the Soviets join us in clearing up ambiguities in the treaty and in resolving the compliance questions that have been raised. I believe that their large new radar at Krasnoyarsk constitutes a clear violation of the treaty and should be dismantled or other steps should be taken as a demonstration of Soviet intent to comply strictly with the treaty in the future.

*We should offer a mutual ban on antisatellite weapons systems. The two sides should agree to stop testing ASATs, to prohibit further ASAT deployments, and to place the strictest possible controls on existing systems, including dismantling. Clearly, ASATs threaten the very satellite systems we rely upon for early warning, surveillance and communications. It is, therefore, in our interest to remove that threat. Moreover, ASATs could undermine any ban on space weapons by allowing space-weapon experiments under the guise of ASAT work, and it would be in the interest of both sides to prevent that.

*We should insist that the Soviets make good on their pledge to table radical proposals for reduction of strategic and intermediate-range weapons. We should also come to the table with our own new proposals. Now that so many understand the importance of getting MIRVed missiles out of both arsenals, we could propose a mutual agreement not to deploy any new MIRVed missiles. As a first step, we might agree not to deploy the MX if they did not deploy the new and very potent SS-X-24. We would be trading a weapon that makes no sense for us for one which should make no r them, if both sides are genuinely committed to controls.

If we thus open up important new arms control options, it should be possible to reach early agreements. In the negotiations, we should move step by step to put controls in place as we can agree on them. We will have to take care that nuclear stability is maintained throughout the process, but we cannot wait until all issues are resolved before implementing each area of agreement. Such a task could take years, if it can ever be accomplished. We should not leave the bargaining table, however, so long as there is any prospect of achieving the arms control successes both sides profess to want -- and surely do need.

We are at a critical point in the effort to reverse the nuclear arms race. We have the opportunity with new leadership in the Kremlin to achieve far-reaching limitations on nuclear weapons. But it will require a high act of statesmanship on both the Soviet and U.S. sides to achieve that objective. Let us show the world that such statesmanship and concern for the fate of humanity are not lacking on our part.