BORIS YELTSIN arrives in Washington tomorrow to discuss the shape of a new relationship between Russia and the United States. But a dominant theme in the prelude to this summit has been a little something left over from the old relationship - the thousands of nuclear warheads stockpiled by both countries.
Mr. Yeltsin has talked optimistically of whacking that stockpile down to 2,500 apiece - not a bad interim goal, considering the absurd current levels of 10,000 or more warheads on both sides. But it appears that 4,700, as proposed last week by the US, will be nearer the mark.
The Russian leader's desire to shrink nuclear arsenals is driven by obvious self-interest: A Russia struggling to be reborn as a democracy doesn't need the economic drag or the physical danger of overseeing a mountain of nukes.
But Yeltsin's desires are constrained by Moscow's tattered but still powerful military establishment and its political supporters. The generals are leery of moving too quickly to junk one of the last remnants of superpowerdom.
Russians suspicions grow when the US seems determined to see the bulk of the cutting done on the mainstay of the Russian force - its land-based missiles equipped with multiple warheads. Why not equally deep cuts in the sea-based multiple-warhead missiles so dear to US military planners?
Why not, indeed. Leaders on both sides may yet conclude that old arguments over "destabilizing" types of weapons can be junked and simply set the warhead total even lower than 4,700 warheads - perhaps 1,000 - deployed as each side sees fit.
The US holds most of the cards in these post-cold-war arms negotiations, so Yeltsin may settle for less reciprocity than he would like, in order to heighten the chances of getting what he most wants - a US commitment to assist Russia financially in its turbulent transition to capitalism.
Washington shouldn't forget, however, that the US, no less than Russia, would be much better off without the burden of maintaining thousands of nuclear warheads, even a few of which, if ever detonated, could do incalculable damage to human society.