Last Chance to Rid World of Big Nukes

The US Senate must soon decide whether to seize - or ignore to America's peril - an unprecedented opportunity to dismantle the ''Soviet'' nuclear arsenal.

Will it act on ratification of the START II treaty?

I say ''Soviet'' arsenal because START II would eliminate the most devastating nuclear missiles built by the Soviet Union in the 1970s and 1980s - among them, the infamous SS-18, which became the very symbol of the Soviet threat. Still deployed in launching silos scattered across a Russian nation undergoing enormous political turmoil, these missiles could at a moment's notice be targeted on the United States.

As matters now stand, this potential threat carries with it a glaring irony. For months, Congress has engaged in yet another debate over whether to construct a national antimissile shield. If ever built, any such system would be monumentally expensive, of uncertain reliability, and available at best sometime in the next century. Meanwhile, we have failed to act on a treaty that would, during that same period, eliminate the one serious missile threat the US has ever faced.

The second Strategic Arms Reduction Treaty has been before the Senate since 1993. Its terms were avidly pursued by the Reagan administration and finally achieved by President Bush with strong bipartisan support. These terms are not just favorable to US national security; many Americans and many Russians alike regard START II as one-sidedly to America's advantage.

The treaty's salient feature is its elimination of every land-based multiwarhead missile in the now-Russian arsenal. For years, these weapons so worried the defense establishment that America spent hundreds of billions of dollars to counter their first-strike potential. That apocalyptic potential remains today.

The cold war may be over. But as we watch President Yeltsin in the hospital and hear the thundering nationalism of those struggling to replace him, we have every reason to lock in, quickly, the gains available from a promising but still highly tenuous Russian-American partnership.

Some assert that Senate action is meaningless in the absence of similar action by Russia's parliament, the Duma. There, START II has been attacked as unduly burdensome on Russia and too favorable to the United States. But precisely because this controversy has roiled the Russian government, hope of implementing the treaty lies in Washington leading the way by demonstrating a full commitment. That would remove the one easy excuse by which the Duma could walk away from Russia's commitment.

Why is the US not acting? Because START II is being held hostage in a squabble over one senator's reorganization plan for US foreign-affairs agencies. There can be no question but that the security of the American people comes first. We have a clear opportunity to enhance that security - by eliminating gargantuan Soviet missiles.

The linkage between START II and the unrelated reorganization matter must be broken - and promptly. Next month's Duma elections may well produce gains by Russian nationalists who view this treaty with skepticism. If so, and if the new Duma then debates whether to abandon Russia's commitment to the treaty, the question of whether the US Senate has already approved START II could quite conceivably determine the treaty's fate.

No senator may wish to go down in history as helping to save the SS-18. But continued Senate inaction on START II could yield that result. Americans should ask the Senate leadership: When will the Senate act on START II?