Only One Issue Bars Arms Pact, Baker Reports

All but final agreement on the Strategic Arms Reduction Treaty, the first in history to actually cut the nuclear arsenals of the superpowers, was announced here Sunday by Secretary of State James A. Baker III and Soviet Foreign Minister Alexander A. Bessmertnykh after four intensive days of negotiations.

“We’ve now reached agreement on almost all outstanding issues--in fact, all of them save for one,” Baker announced.

The remaining, highly technical issue concerns the definition of missile “throw-weight”--how much payload weight can be carried, or thrown, a given distance. It is important in determining how many warheads a missile can carry.

Despite the last sticking point, which was unexpected, Baker and Bessmertnykh appeared highly pleased with the outcome. They hinted that the matter could be worked out by technicians before Wednesday, when President Bush and Soviet President Mikhail S. Gorbachev meet in London at the end of the economic summit there. Baker and Bessmertnykh will also meet then.

The two presidents at that time could announce final completion of the START pact as well as set the date for a bilateral U.S.-Soviet summit in Moscow in late July or early August to formally sign the agreement, which would cut long-range offensive nuclear weapons by one-third overall.

“The long journey of nine years is coming really to an end,” Bessmertnykh said. Negotiations on the agreement were begun almost a decade ago, although serious talks go back only about five years, to when Gorbachev took power.

Baker cautioned, however, that “you never know until the lid is nailed on the box” that the treaty is finally done. “This is a very, very serious treaty, which deals with the strategic balance (of U.S. and Soviet nuclear weapons) for the next 15 or 20 years. We’re determined to get it right.”

Agreements reached here must now be translated into legal “treaty language” by U.S. and Soviet specialists in Geneva, Baker also pointed out.

“Really, we take the view that nothing is agreed until everything is agreed,” Baker said. “But having said that, we are writing the elements of common ground so that we will understand exactly--both sides will know exactly what has been agreed to here. And if we can cover this one last issue, we will have an agreement.”

If the last hitch is resolved by Wednesday, Baker said, specialists could formalize the treaty in time for it to be signed in Moscow two weeks later.

Bessmertnykh portrayed the settlement of more than a half dozen questions since Thursday as a series of compromises. “On one item the Soviet side might have moved more,” he said, “on another, the United Sates might have moved more” to reach a “balance” in the end.

In fact, the United States seems to have won more on the chief issue, called “downloading,” which deals with how many warheads can be removed from an existing missile to meet the START ceilings.

The Bush Administration feared that creating too many empty, or spare, spaces would permit the Soviets--if they chose to break the treaty someday--to secretly “upload” and suddenly confront the United States with a greater arsenal than the treaty permits.

The two sides compromised on a downloading maximum--1,250 empty spaces--that was far closer to the U.S. position of 1,000 than to the initial Soviet demand for more than 2,150, Baker said. They also agreed to allow up to three types of missiles to be downloaded, which was an outcome more favored by the Soviets.

On balance, however, “it’s a good deal for us,” said Jack Mendelsohn, deputy director of the private Arms Control Assn.

“This last issue (throw-weight) can be easily settled,” he added. “I’d guess Bush and Gorbachev will announce its resolution Wednesday and also set the date for the Moscow summit.”

The broad terms of the START agreement have long been agreed: 6,000 nuclear weapons, of which no more than 4,900 warheads can be on ballistic missiles, either land-based or submarine-based. Each side has about 9,500 missile warheads today.

The remaining 1,100 weapons, carried by bombers, include bombs, short-range attack missiles and longer-range cruise missiles. Complicated counting rules have been devised that, in reality, permit between 2,000 and 4,000 nuclear devices in this category.

The bottom line is that the United States, now with 12,000 nuclear warheads, will legally be permitted to deploy about 9,000. The Soviet Union, with about 11,000 warheads now, will field 7,000 to 8,000, although with new bombers.