Growing nuclear arsenals in Europe have both sides on edge

Nuclear proliferation on the European continent is an increasingly worrisome factor in arms control. Alarmed at the new Soviet SS-20 missiles aimed at them five years ago, the NATO countries announced their ``dual track'' decision. They vowed to deploy new missiles of their own if the parallel effort to negotiate the removal of such weapons failed.

Those intermediate-range nuclear force (INF) talks at Geneva did not result in an agreement. When the deployment of NATO's US-built Pershing II and ground-launched cruise missiles began in late 1983, Soviet negotiators walked out of the talks.

The new beginning at Geneva next week finds a steady increase in new medium-range nuclear missiles on both sides, a trend that could accelerate in the future if the refurbished ``umbrella'' talks are not successful.

At a meeting of NATO defense ministers last month, US Defense Secretary Caspar W. Weinberger announced that the number of operational Soviet SS-20s had increased to 387 missiles and 1,161 warheads (three warheads per missile). Mr. Weinberger said at least nine new SS-20 bases were being built, and that ``the rate of construction [had] increased enormously.''

Based on this new construction, Assistant Secretary of State Richard Burt said recently, ``it is possible at this stage to sluggest that the ultimate number of SS-20 deployments . . . is likely to range between 450 and 500.''

The SS-20 represents a significant advance in Soviet missilery. The two-stage rocket is solid-fueled, therefore more reliable and able to react more quickly. And it is mobile, and therefore easier to hide and harder to verify. Some Western analysts say the SS-20 could be made intercontinental (and therefore able to reach US targets) by lightening its warhead load. The SS-20 reportedly has been flight tested in an over-the-North Pole direction.

Some analysts say that neither the new NATO missiles nor the SS-20 appreciably changes the military balance in Europe, because theater nuclear weapons have been an important part of both arsenals for years. But the more capable SS-20 and Pershing II are perceived as potential first-strike weapons. And in superpower relations as well as in arms control negotiations, perceptions can weigh more than theoretical military capability.

NATO's planned deployment of 108 Pershing II ballistic missiles and 464 cruise missiles (each with a single nuclear warhead) in five countries does not nearly match warhead for warhead the number of SS-20s already in place.

But Moscow views the Pershing II as particularly threatening because of its accuracy as well as its range and speed. The new missile has a maneuverable warhead, allowing it to fall within 100 feet of its target.

This makes it at least several times more accurate than the SS-20. It can travel farther than the older Pershing I and reach Soviet soil in a few minutes.

Soviet leaders also are concerned about the planned modernization of British and French nuclear forces. Over the next several years, these two countries plan to increase their arsenals of land- and sea-based nuclear warheads fourfold to about 1,200. This will include the new, very accurate and longer-range US-built Trident II missile, to be deployed on British submarines.

``New British and French nuclear forces will present the Soviet bloc with an entirely new strategic situation,'' warns retired US Army Lt. Gen. George M. Seignious II. ``British and French submarines alone will be capable of inflicting staggering damage on the Soviet Union.''

While this could turn either of these two US allies into ``the world's third nuclear superpower,'' Mr. Seignious, a former director of the US Arms Control and Disarmament Agency and now vice-chairman of the Atlantic Council, predicts that the Western alliance could in fact be weakened as a result.

``The reason is that they will be deployed largely in potentially vulnerable and destabilizing modes,'' he wrote in a Foreign Policy magazine article. ``Perhaps most important, these forces will almost certainly spark a counter-buildup by the Soviets and fatally complicate the task of arms control.'' -- 30 --{et