Oh, One More Thing . . . Despite last-minute maneuvers to wring out concessions, a far-reaching strategic-arms treaty may be ready at last

By GEORGE J. CHURCH

As the week began, some diplomats were calling it the Big Pre-Summit Stall. Endgame, however, might have been a more accurate term. In a manner familiar to all negotiators who have ever raced a deadline, Soviet and American negotiators sought to extract the last possible concession before turning over a nuclear-weapons agreement for their chiefs, George Bush and Mikhail ; Gorbachev, to announce with a flourish at their summit meeting next week. But by the time Secretary of State James Baker left Moscow on Saturday, after four days of talks with Soviet Foreign Minister Eduard Shevardnadze and a five-hour visit with Gorbachev, basic agreement on the most significant arms-control treaty ever negotiated seemed ready for the summiteers to approve.

Baker looked tired when he finally emerged from discussions he described as "heavy lifting." The U.S. and the U.S.S.R. had reached a "trail- blazing" agreement to ban superpower production of chemical weapons and to destroy existing stockpiles that, said Baker, could serve as a model for the global ban now under negotiation by 40 nations. They also cleared away the biggest obstacle to a strategic arms-reduction treaty: how to cut air- and sea-launched cruise missiles. Settling on the complicated formulas to regulate these elusive, nuclear-tipped weapons opens the way to a sweeping treaty that will trim overall long-range nuclear arsenals 30% to 35%. But Baker and Shevardnadze could not bridge their differences on how to reduce conventional troops and tanks in Europe. Baker said the U.S. had offered a "new" approach, but "our counterparts were unable to respond at this time." Still, it is likely that Gorbachev and Bush will sign a full treaty by year's end.

The remaining issues never did look insoluble, at least from a technical viewpoint. Negotiators long ago settled on the cuts -- roughly 50% -- to be made in the most devastating nuclear weapons: warheads carried by land- and submarine-based ballistic missiles and aircraft. But proliferating cruise missiles presented more difficulty. The U.S. at one point thought it had Moscow's agreement to leave sea-launched cruise missiles out of the treaty; each side would merely make "politically binding" declarations of how many it intended to deploy. Last week the U.S. essentially got its way when the Soviets agreed to a separate declaration outside the main treaty that would limit each side to 880 SLCMs.

On air-launched cruise missiles, which could be launched by bombers from outside an enemy's airspace and beyond the reach of its air defenses, the question was the range of the weapons to be limited. The U.S. initially wanted to apply curbs only to missiles with a range of more than 932 miles, while the Soviets proposed 186 miles. In the end, the U.S. adopted a Soviet offer to set the range at 372 miles. At the same time, Moscow agreed to accept U.S. rules for counting the number of ALCMs each side deployed.

Technicalities, however, were not the real point; political will was. On the American side, there was some suspicion that Gorbachev would be unable to make any but the tiniest additional concessions. Reason: he was under fire from military leaders who (with some justification) feared that the treaty was shaping up in a fashion skewed in favor of the U.S. On the Soviet side, there was some concern that the U.S. would try to push an already embattled Gorbachev to the wall. One way to do so: insisting on a ban on mobile missiles with multiple warheads, which the U.S.S.R. -- but not the U.S. -- has already deployed. While several disagreements like this one remain unsettled, both sides proved willing to do some compromising.

Which does not mean the millennium has arrived. For one thing, an intricate verification procedure remains to be completed. Also, START in some ways seems designed to curb the arms race of the 1980s rather than the one that might occur in the '90s; it makes its greatest reductions in the numbers of ballistic-missile warheads, which have been gradually losing prominence to the newer cruise missiles as both sides modernize their nuclear arsenals. Consequently, the cut in total warheads deployed will not be 50%, as often stated, but 30% to 35%. Under some circumstances, there could be no overall reduction: because of complex rules that count bombers as carrying fewer warheads than they are capable of carrying, the U.S. in theory could wind up not with the 6,000 warheads that START supposedly allows each side, but with more than 11,000. Still, the treaty, when and if signed, will mark a step toward U.S.-Soviet cooperation to lessen the arms race -- and a step away from the threat of nuclear annihilation.

CHART: NOT AVAILABLE

CREDIT: TIME Chart by Steve Hart

CAPTION: HOW SOME OF THE CUTS WOULD WORK

With reporting by J.F.O. McAllister with Baker and Bruce van Voorst/Washington