Hurdles across the path to arms control. `Star wars,' Libya, and Chernobyl complicate fifth round of talks

There is little optimism in Washington as the superpowers resume their nuclear arms control talks. Diplomatic and arms experts say that the fifth round of the negotiations, which begins in Geneva today and will last six weeks, is unlikely to break the stalemate over fundamental arms issues. Among the reasons for the lack of optimism:

American and Soviet negotiators cannot get down to serious negotiations and make meaningful progress without new instructions. That requires a back-channel dialogue, which is absent at the moment. It was hoped that the planned May meeting between US Secretary of State George P. Shultz and Soviet Foreign Minister Eduard A. Shevardnadze would lead to new negotiating orders. But Moscow canceled the meeting after the United States attacked Libya, and it has yet to be rescheduled.

The Reagan administration continues to say that the area of intermediate-range nuclear forces (INF) in Europe offers the most hope for an arms agreement. But the American proposal on INF, which calls for the elimination of medium-range missiles (the so-called ``zero option''), has encountered resistance in Western Europe. Any agreement acceptable to the allies would probably have to include the continued deployment of some Pershing 2 missiles as well as cruise missiles.

Progress on intercontinental strategic arms is frustrated as long as the Soviet Union insists on a ban on President Reagan's Strategic Defense Initiative (SDI), and the US refuses to consider any compromise on its ballistic missile defense program.

The Reagan administration continues to be divided over arms control policy.

Even as Soviet and American negotiators resume their work, there are indications that the administration is relaxing its standards for future deployment of SDI, popularly known as ``star wars.'' Until now one requirement for a space-based defense shield has been that it cost less than Soviet offensive measures to counter it -- a concept known as ``cost effectiveness at the margin.''

But a report submitted recently to Congress by the Defense Department's Strategic Defense Initiative Office appears to back away from that criterion. According to government sources, the language on cost effectiveness has been watered down over last year's report.

Paul H. Nitze, special adviser to the President on arms control, has long said that before being deployed, a defensive shield must be cost-effective, affordable, reliable, and survivable. Failing these standards, Mr. Nitze implies, SDI is unrealistic.

Defense Secretary Caspar W. Weinberger has long questioned the criteria, however. And in recent months Lt. Gen. James A. Abrahamson, director of SDIO, has indicated that the Pentagon seeks to change the standards to a stress on ``affordability,'' on grounds that SDI is desirable despite the high costs. ``It looks as if Abrahamson is trying to put distance between himself and the Nitze criteria,'' says a congressional arms expert.

Nitze is said to be extremely unhappy about the SDIO report and the Pentagon's playing down of the cost factor. Many arms specialists say Nitze set the SDI criteria and had them incorporated as US policy in order to give the Soviets an incentive to negotiate and to enable President Reagan or the next US president to back away from SDI.

Although expectations for the current round of arms talks are not high, it is not thought that a lack of progress will frustrate a second summit meeting. There are signs that Soviet leader Mikhail S. Gorbachev is still interested in a summit, although the date could slip into next year. Diplomatic experts suggest that Mr. Gorbachev cannot be seen scuttling a summit if he wants to enhance his image as a peacemaker. The nuclear accident at Chernobyl, which has provoked anger in Western Europe and the US, adds to pressures on the Soviet leader to occupy a moral high ground on East-West relations.

There is even speculation that, in the wake of Chernobyl, the Soviets may offer a new proposal in Geneva. In any event, they are using the disaster to stress the nuclear danger and the need for progress toward disarmament.

Administration officials believe the Soviets themselves are not optimistic about progress in Geneva. The coming round, they say, will explore the possibilities for future agreement rather than try to nail down something concrete.

``We're getting signals that they do want the summit to come off,'' one US official says. ``But that doesn't translate into an arms control breakthrough. We don't see them prepared for major concessions -- and after Chernobyl they're not about to do anything but hunker down.''

If the chances are dim for an INF or strategic-arms agreement by the time of the second summit meeting, diplomatic observers say, another summit could conceivably agree on the principles of an accord and give the Geneva negotiators new instructions. In such case, the next or sixth round of arms talks would be the scene setter.

Administration officials say the US in this round hopes to make progress on verification measures and move closer to an agreement on INF. They continue to voice disappointment that the Soviets have not spelled out the details of their own proposals or responded seriously to US proposals.