As `star wars' moves ahead, conflict with ABM treaty looms

President Reagan's proposed missile defense network of lasers and rockets may run afoul of the 1972 antiballistic missile (ABM) treaty before the decade is out. Specifically, the United States may violate the ABM treaty simply by testing various parts of ``star wars,'' or, as it is formally called, the Strategic Defense Initiative (SDI). Although the administration has shown it is sensitive to this conflict, officials acknowledge that if SDI proceeds as planned, this Rubicon would be crossed around 1990.

A private report on this problem was issued Tuesday in Washington. The same day, thousands of miles away, US and Soviet negotiators sat down in Geneva for their first session of talks on space arms and defense.

The antiballistic missile treaty was one of the major accomplishments of the original Strategic Arms Limitation Talks (SALT), begun 15 years ago. Currently, it limits both the US and the USSR to one small system of defenses against incoming ballistic missiles. The rationale behind the treaty was that full-scale ABM systems would lead to a viciously expensive arms spiral, as each nation piled on enough weapons to overcome its opponent's defenses.

Widely regarded by experts as one of the most successful of all arms treaties, the ABM pact had faded into the background until its recent, sudden reemergence as a topic of official discussion.

For one thing, the Reagan administration has not been shy about accusing the Soviets of violating arms treaties in general, and the ABM treaty in particular. A February White House report, citing among other things radar construction, charged that ``the USSR may be preparing an ABM defense of its national territory.''

For another, President Reagan's announcement of the SDI program could not help but raise the issue of possible US violation of the treaty. A fully deployed ``star wars'' defense would break the pact as it now stands. The more immediate question is when ``star wars'' research would violate the treaty, which prohibits research and development of ``components'' of an ABM system.

Administration officials are sensitive to this conflict. Lt. Gen. James Abrahamson, director of the SDI effort, has often said that current SDI research is fully in accord with all existing arms treaties. But in recent congressional testimony, he has acknowledged that at some point ``we would have to depart from the [ABM] treaty.''

Earlier this month, before a House subcommittee, General Abrahamson indicated this fateful step would not come before the early 1990s.

But some outside experts think the step would come earlier. The National Campaign to Save the ABM Treaty, an arms control group that includes Gerard Smith, chief negotiator of SALT I, released a report Tuesday that concludes that ``development and testing now planned for 1988-93 as part of the SDI will be inconsistent with the ABM treaty.''

The difference here turns on the interpretation of treaty phrasing. For instance, the Smith group's report argues that airborne testing of the Airborne Optical System, a sensor project that is part of SDI, would constitute development of ABM components, which would violate the treaty. The administration, for its part, contends that such tests would be demonstrations of subsystems, which are permitted.

The treaty phrasing at issue ``has a high degree of generality,'' says John Rhinelander, legal adviser to the SALT I delegation and a contributor to the report. He urges that the US and USSR hammer out some specific language.

To help shore up the ABM treaty, the Smith group also recommends a halt on construction of new large radars and a ban on testing of antisatellite weapons.

The administration has taken some measures that have the effect of putting off the impact of ``star wars'' on the treaty, Ambassador Smith notes. Airborne testing of Talon Gold, a space-based tracking system, has been postponed. And Smith praised President Reagan for his recent statement that he would ``reverse the erosion of the ABM treaty.''

The administration itself is putting together a report that will deal with the effect of SDI on the ABM treaty. Congress, which asked for the report, set a March 15 deadline, which has passed without a finished report in sight.

A congressional aide said a classified version of the report might be delivered to Congress later this week. Administration officials explain their tardiness by noting that the executive branch employees who are compiling the paper have been tied up writing position papers for the Geneva arms talks.