Piecing together the puzzle of arms control

What would be the advantages of Euromissile arms control for the West? The Soviet Union would destroy some 1,200 SS-20 and SS-4 warheads in the range from 1,000 to 5,500 kilometers (600 to 3,400 miles). The West would destroy only some 200 Pershing 2 and cruise missile warheads. These weapons all fall within the long-range subcategory of INF (intermediate-range nuclear forces, or Euromissiles).

If the shorter-range (500 to 1,000 km, or 300 to 600 miles) INF are included in a deal to remove INF from Europe, the Soviet Union would further destroy some 120 SS-12/22s and -23s, while the West would destroy nothing in this category. (In the Western view, that is. The Soviets - after initially not mentioning the 72 Pershing 1 missiles that West Germany has, with warheads controlled by the United States - now say these should be destroyed too.)

What would be the advantages for Moscow?

With the American Pershing 2s gone from Europe, there would no longer be a precise, fast American missile stationed in Western Europe that could hit Soviet command centers and other crucial targets west of Moscow within some 10 minutes of launch.

If the Soviets would destroy far more warheads, why is the West so worried about the deal that is shaping up?

The West worries because elimination of Euromissiles above 1,000 (or even 500) km could enhance the value of lower-range missiles, between about 150 and 500 km. Here the Soviet Union has hundreds of Scud and Frog missiles, while the West has nothing, since the West never thought this category was very important.

The West never thought through the consequences of eliminating all intermediate-range missiles in Europe back when it proposed this solution in 1981.

Now that a ``zero solution'' (that is, leaving zero INF in Europe) seems imminent, Western strategists are wondering: If European nuclear weapons go down to ranges that essentially could be used only in Germany, will the Soviet Union still believe that the US might use nuclear weapons to retaliate for any Soviet attack on West Germany?

Does all this mean that the West is now backing off the Euromissile deal? Was last week's statement by a group of NATO officials that they want to get rid of all medium-range warheads worldwide (instead of leaving 100 in Soviet Asia and 100 on US territory) essentially put forward as a new demand that could kill the deal?

Yes, it seems, in the case of US Defense Secretary Caspar Weinberger, according to reporting out of Washington. No in the case of the other signatories. To the others the communiqu'e was basically a holding operation while the allies wait for Bonn to make up its mind on the ``double zero option'' (that is, removing shorter-range INF from Europe in addition to the longer-range Euromissiles). All along, the US has said that it would prefer to eliminate all the warheads, but that it's willing to leave 100 each if Moscow insists. West German officials have already said they will agree to Euromissile arms control; the question now is essentially whether they will decide to include the shorter-range missiles in the deal or not. The hope within the alliance is that by the NATO foreign ministers meeting in Reykjavik, Iceland, in June, Bonn will finally have stopped dithering.

So, is Euromissile arms control important or not?

A Euromissile deal would not disrupt the overall balance of nuclear weapons (and the Euromissile numbers are still quite small in any case, when compared with the total 50,000 warheads each that the superpowers possess in their arsenals). The nuclear materials would just go into other missiles with longer or shorter rangers than the 1,000 to 5,500 km part of the spectrum.

Euromissile arms control is extremely important for other reasons, however.

First, it's easier to solve (despite the present confusion) than the much more crucial issue of ``deep cuts'' in superpower strategic (intercontinental) warheads. Euromissiles therefore serve as an experimental ground where the superpowers can sound each other out in an area where not too much is at stake and see if they are serious about going further in what really would be a historic arms control agreement of making drastic cuts in strategic offensive weapons.

Second, verification issues in the past have always been the main stumbling block to dramatic arms control. But the Soviets now seem ready to accept the kind of intrusive on-site inspection that would be needed to have confidence in verification of deep cuts.

The Euromissile negotiations are an ideal forum in which to work out precise verification measures - especially since it's a lot harder to monitor a small number of weapons than the total absence of those weapons. This means that if the two sides can agree on the stringent measures to check on the 200 residual intermediate warheads in Soviet Asia and on US territory, they will have essentially solved the issue of verification of strategic cuts.

But surely it's pie in the sky to hope for comprehensive arms control. Haven't the Soviets given up on striking a strategic offensive deal with President Reagan? Just look at all the criticism from Moscow of the new American draft treaty in strategic weapons, and the continuing deadlock over ``star wars.''

Watch what the Soviets do, not what they say. And listen to what they say very carefully, to distinguish tactical from fundamental criticism. Of course the odds are against comprehensive arms control; they always have been. But the Soviets have not given up on Reagan by any means. They have been negotiating in very business-like fashion in the Geneva talks this entire year. They will soon be presenting their own draft treaty in strategic offensive weapons in Geneva. And the two sides can then begin working toward a joint draft treaty.

The sticking point now is sublimits on heavy missiles and other subcategories within the 6,000 overall warheads both sides already agreed to reduce to at the 1986 Reagan-Gorbachev summit in Reykjavik. But once the Soviets decide to go for the endgame, they will come back to the sublimits they themselves endorsed pre-Reykjavik - and these aren't far from the US sublimits they now scorn.

Moreover, the Soviets have been making some very interesting - and very little noticed - shifts in their basic position on Mr. Reagan's Strategic Defense Initiative (SDI, or ``star wars''). They now seem to be focusing on an interim period of ``non-deployment'' of any star wars system - which is eminently negotiable - rather than on prohibiting research, which is eminently non-verifiable and therefore non-negotiable. They are floating the idea that, instead of requiring Reagan to commit the US not to deploy a space defense at the end of such an interim period (which was their stance at Reykjavik), they would simply say unilaterally that if either side eventually deploys star wars without agreement of the other, then the other would no longer be bound by whatever cuts in offensive weapons had been agreed on earlier.

In addition, the Soviets have come back down to the 10 years tentatively agreed on in Reykjavik as the period of nondeployment of space defense. Earlier, the Soviets had added a three-to-five-year buffer period of compulsory negotiations before either side could deploy after expiry of the interim period. Now, however, they have incorporated this negotiating period into the 10 years. The US also retreated after Reykjavik, from 10 to seven years of nondeployment - but again the difference between seven and 10 is eminently negotiable.