Nitze assesses Soviet `star wars' offer. Says discussing new proposal won't hurt SDI research

Just how far have the Soviets moved to accommodate President Reagan's pet Strategic Defense Initiative (SDI or ``star wars'') program? This is the key question as administration officials prepare for Secretary of State George Shultz's visit to Moscow in three weeks.

So far the answer remains ambiguous, but presidential arms-control adviser Paul Nitze went on record Monday at a conference on European defense as saying that discussing the deal the Soviets are now proposing would not hamper Reagan's SDI research program.

What the Soviets offered when Foreign Minister Eduard Shevardnadze visited Washington two weeks ago, according to Mr. Nitze, was either a ``labs-list'' regime during a 10-year period of ``nonwithdrawal'' from the 1972 Anti-Ballistic Missile (ABM) Treaty, or else mutual commitment to adhere ``strictly'' to the treaty. The two sides tentatively agreed to a 10-year further observance of the ABM Treaty at the superpower summit in Reykjavik, Iceland, a year ago but did not define that adherence. The ABM Treaty banned development, testing, or deployment of ABM (star wars) ``systems or components'' in space.

The Soviet ``labs-list'' regime would involve superpower negotiation of a list of thresholds of exotic technologies to be barred from space. Anything above a set size of mirrors or power of lasers could be tested on earth, either in laboratories or at test sites, but not in space. But any ``subcomponents'' below those levels could be tested in space, including specifically for ABM purposes, Nitze told his audience at the conference sponsored by the American Association for Advancement of Science.

``It took some time to get a clear statement'' on this from Sheverdnadze's team, Nitze said, but ``we finally got that, in black and white.''

As Nitze explained his assessment, the original ABM Treaty, while specifying how the signatories would define ``components'' of traditional ABM systems built from ballistic interceptor missiles and radars, could not foresee precisely what new or ``exotic'' technologies would entail. And Soviet negotiators at the time of signing refused to accept American-proposed language on banning devices ``capable of substituting'' for the ABM missile, launchers, and radars identified in the ABM Treaty. The Soviet list now recognizes this gap, Nitze said, and it ``illustrates a point, a basic point:'' the issue is not a ``narrow'' vs. a ``broad'' interpretaton of the treaty, but rather, there is ``a lot of uncovered ground in the treaty.'' Nitze said ``the whole theory'' was that when a gap of this sort was identified, then the parties should ``talk about it.''

The ``broad interpretation'' Nitze referred to is the Reagan administration position that exotic technologies are exempt from the prohibition on testing in space, since they were dealt with in an annex to the ABM Treaty rather than in the main body of the treaty. The US Senate has gone on record as favoring the ``narrow'' or traditional interpretation, under which the prohibitions apply to exotic technologies as well. So far the distinction has been academic, since the SDI program has remained within the narrow interpretation in practice .

Mr. Sheverdnadze's alternative offer this month was that both sides abide ``strictly'' by the ABM Treaty ``as negotiated and ratified,'' Nitze said. ``In other words, we agree to, I guess, the Senate interpretaton,'' though ``I don't know whether (the Soviet offer) means our ratification process or theirs.''

At the same time the Soviets moved on ABM issues this month, they also moved on the Strategic Arms Reductions Talks (START) aiming at halving offensive nuclear warheads. At the AAAS conference, Nitze expressed surprise at the degree of interest the Soviets showed in START and said, ``We did straighten out two or three items of important difference...'' during Sheverdnadze's visit to Washington.

Other American officials identified the most important of these as giving a specific number halving the Soviet Union's powerful heavy missiles, down to 154 SS-18s, with a total of 1,540 warheads, and specifying for the first time that these numbers would not subsequently be increased. The officials said also that the Soviets expressed for the first time a willingness to study the seven years preferred by the US as the period of implementation of any START treaty. Until now the Soviets have insisted on a five-year period of implementation.