Soviets Quietly Offering Deal on Defensive Arms : Disarmament: In a new bid to curb U.S. ‘Star Wars’ tests, the Kremlin says it’s willing to scrap the anti-missile defense system around Moscow.

Moscow, in a new effort to curb the U.S. anti-missile program known as “Star Wars,” has privately offered to eliminate entirely its own existing anti-missile system around Moscow, according to Bush Administration and congressional sources.

The Soviet Union would eliminate the anti-missile weapons it now has deployed around its capital if the Administration would commit itself to a narrow interpretation of the Anti-Ballistic Missile Treaty, Soviet diplomats have suggested. A narrow interpretation of the treaty would act as a brake on some facets of the Strategic Defense Initiative or “Star Wars” program.

Soviet arms negotiators also have indicated that the Kremlin is prepared to be more flexible on the kinds of experiments with anti-missile components that would be permitted in the future--a key issue for SDI.

The possible concession on Moscow’s ABM network, which has been broached twice by Soviet diplomats but not yet formally proposed, comes at a time when the Administration is already conducting a detailed review of space defense issues, particularly the U.S. negotiating position at Geneva.

The review probably will lead to changes in the U.S. position that indirectly constrain SDI, officials acknowledged.

The new Soviet moves on ABM came in advance of Soviet President Mikhail S. Gorbachev’s recent “de-linking” of the space defense issue from strategic arms talks aimed at cutting offensive weapons by about 50%. But it appears to have the same goal as the previous attempt to link SDI and the strategic arms talks: restraining the SDI program.

Some conservatives, such as Frank J. Gaffney Jr., a top Pentagon official in the Reagan Administration, fear that the U.S. review of anti-missile defenses will be the fig leaf behind which SDI is curtailed or even abandoned by an Administration that is far from enthusiastic about the program.

The ABM Treaty, signed in 1972, permits each side to have up to 100 ground-based rocket interceptors ringing either its capital city (Washington or Moscow) or a single offensive missile field. The Soviets initially put 64 interceptor missiles around Moscow. The United States declared that it would not build such a network because it could be easily overwhelmed.

Over the last decade, the Soviets have been replacing their initial system with a two-tiered network at a cost measured in hundreds of millions of dollars, U.S. officials said. About half of the interceptors are long-range missiles that would engage incoming warheads outside the atmosphere. The rest are shorter-range, fast-accelerating missiles intended to hit warheads after they have re-entered the atmosphere.

The upgraded Soviet system also can be overwhelmed by incoming warheads, according to the Pentagon’s new “Soviet Military Power” booklet, although the Defense Department said that the network does provide some degree of protection for “high value” targets in Moscow.

Sources said privately that more than 20% of all the “high value” targets in the Soviet Union, including the leadership shelters and military command headquarters, come under Moscow’s new anti-missile umbrella.

Whatever the military value of the Moscow system to the Soviets, eliminating it could offer them a significant diplomatic gain. Such a move could rob SDI proponents of one of their principal arguments: that the Moscow network could become the core of a nationwide anti-missile network if the Soviets suddenly chose to break out of the ABM treaty.

Although SDI is not a formal topic of the Administration’s review of space defense issues, officials concede that decisions made about negotiating stances will have an indirect impact on the SDI program.

For example, a senior White House official said that the Administration will “not necessarily” continue holding to a key negotiating position of the past--the U.S. refusal to compromise U.S.-Soviet differences on the ABM interpretation by agreeing to a list of prohibited and permitted tests that can be legally conducted under terms of the treaty.

“We historically have been opposed” to negotiating such a list, the senior official said, “because we don’t know right now what we may or may not want to do” under the SDI program.

“We will go back now and we’ll look over our positions in all these respects,” he said. “I’m not saying we’re willing to drop it. What we have is a new condition now that wasn’t there before (i.e., “de-linkage”), and we’ll go back and review all of the positions related to defense in space and see what it is that makes sense now in light of this.”

Besides the Soviet moves, the White House is also under domestic pressures from congressional Democrats and the Joint Chiefs of Staff to negotiate a list of permitted and prohibited tests. Each has a different reason, however.

Sen. Sam Nunn (D-Ga.), chairman of the Armed Services Committee, wants such a list so that Pentagon budget requests are not defeated by liberals who fear that the Soviets will abrogate the arms treaties if the United States goes too far in SDI testing.

The Joint Chiefs want a list, according to a knowledgeable U.S. official, so that the Soviets--who have their own “Star Wars”-like program going unconstrained by Congress--do not steal a march on the United States with some test that will constitute a technological breakthrough.