GENEVA -- Has the decade-long effort by the United States and the Soviet Union to achieve an accord reducing strategic nuclear arms been overtaken by events?

This seems to be the view of some in Washington, conservatives and liberals alike, who maintain that the arms reduction talks, or START, have become a relic of the rapidly dissipating Cold War.

One school of thought holds that in the 1990s, East-West arms control will basically take care of itself: The superpower nuclear arms race, it is said, will be superseded by new forms of U.S.-Soviet cooperation, as exemplified in the Gulf crisis, and by economic realities that will curb military spending. It is thus suggested that START, a difficult and complex diplomatic exercise, can be abandoned with little political or military harm.

But putting START on the back burner would be a huge error. For one thing, although Mikhail Gorbachev's Soviet Union is facing unprecedented economic problems, Soviet strategic nuclear programs are surprisingly robust: Moscow is developing and deploying new land- and sea-based missiles, strategic submarines and aircraft. The idea that some kind of "invisible hand" will wind down the nuclear arms race is simply silly.

Thus, without START, a significant tension could develop between U.S.-Soviet political cooperation on the one hand and nuclear arms competition on the other -- a tension that could ultimately threaten the new relationship between Washington and Moscow. It is hard to imagine how the two nations are supposed to cooperate in building a new international order if they remain nuclear adversaries.

Recognizing this, the veteran arms controller Paul Nitze and others advocate a different course: They want to abandon the nearly finished current negotiation in favor of new talks designed to strengthen nuclear stability by seeking more far-reaching limitations on U.S. and Soviet forces. In particular, there is growing interest in focusing in new negotiations on further cuts in U.S. and Soviet land-based missiles with multiple warheads -- the systems which most threaten the strategic balance. There is especially strong support for seeking to eliminate altogether the Soviet force of SS-18 heavy missiles.

There can be no doubt that the new, positive chemistry in U.S.-Soviet relations opens up new opportunities for arms control. Recognizing this, George Bush and Mr. Gorbachev, in a statement released during their meeting in Washington last June, announced that the two sides would seek in new negotiations "to reduce further the risk of outbreak of war" through "further stabilizing reductions in the strategic arsenals of both countries." In particular, the statement underscored that in the new talks, a special focus would be placed on reducing missiles with multiple nuclear warheads, especially the Soviet heavy missiles.

The question, then, is not whether the time has come for the United States to adopt a more radical agenda for nuclear arms control. It is whether the best way to do this is to junk START and move on to something new.

There are several good reasons for not doing so. First of all, START is just too good to junk. The emerging agreement would not only cut both sides' nuclear forces by about a third, it would also slash Soviet SS-18s by half. It would protect important U.S. technological options, such as strategic defenses, and it would usher in a revolutionary regime of on-site inspection for verifying compliance.

Moreover, while the U.S.-Soviet statement on new negotiations outlines a general approach to future nuclear reductions, it doesn't represent anything close to an agreement on the details. Preliminary discussions have already shown that the two sides will pursue different agendas in the new talks. American negotiators, for example, will concentrate on cuts in land-based missiles with multiple warheads while their Soviet counterparts will also want to include sea-based missiles. And while American diplomats will seek to focus on ballistic systems, Soviet officials have already indicated they will argue for tighter constraints on air- and sea-launched cruise missiles.

Despite the new opportunities, then, U.S. and Soviet negotiators will quickly find that implementing a more radical agenda for nuclear cuts will be more difficult and time-consuming than it appears at first glance. Also, it would be risky to place all our arms control chips on a new, protracted negotiation in a period of great political flux in the Soviet Union: After abandoning START, we could find some years from now that a new Soviet leadership would be unwilling or unable to agree to a new, more ambitious arms control regime.

Further, if we suspend START in favor of new talks, the military picture will remain unchanged for now. No heavy missiles would be retired. No inspections would take place. No reduction in the overall threat would occur. We would pass up cuts the Soviets have already accepted for the promise of deeper cuts they might -- or might not -- accept in the future.

In the end, it makes the most sense to finish up START and then move on to a bolder enterprise. A START treaty will provide a firm political base for moving on to a new negotiation. Militarily, the agreement will result in the first substantial reductions of strategic arms in history. Equally important, a START treaty this year will become an important building block in constructing a new international order based in part on U.S.-Soviet cooperation.

The writer is chief U.S. negotiator at the strategic arms reduction talks.