Why Moscow cares

IN the run-up to the Geneva summit in November, one attitude by the Soviets seems to stand out above all others. Moscow does not like the idea of President Reagan's Strategic Defense Initiative, popularly known as ``star wars.'' The vast propaganda apparatus of the Soviet Union has been harnessed for a good year now to the primary task of trying to convince West European and American public opinion that star wars is a bad thing and ought to be abandoned.

Moscow's main bargaining position is that it will agree to a major cut in offensive weapons, something the United States has long wanted, but only on condition that President Reagan will promise that there will be no testing or deployment of the defensive weapons that Mr. Reagan hopes will emerge from the research which is now well under way.

Why does Moscow spend such vast effort to head off a project that is as yet largely a dreamboat idea, which many experts doubt will ever work?

The answer is that if it did work it would wipe out 10 years of highly expensive Soviet effort in achieving ``equivalence'' (some say superiority) in offensive nuclear weapons. They would be back where they were before 1975, when they were a second-rate nuclear power.

From early in the 1950s to 1975, they were the second-largest nuclear power, but well behind the US. The Cuban missile crisis in 1962 proved the point, and it was undoubtedly the reason they were ready in 1975 to start deploying the weapons that moved them into first rank. Their humiliation in 1962 made them resolve never to be caught again in a confrontation with the US while inferior in nuclear power.

They set out then to become the equal of the US. What must have been a massive and highly expensive industrial effort finally paid off in 1975 in the deployment of the first of their SS-18 missiles. In two of its five models it lifts a single warhead with a power of 20 megatons. This is the most powerful nuclear weapon in deployment today.

The Soviets have 668 of the SS-18 and SS-19 missiles all carrying heavy blows and all supposedly able to take out many, some say most, of America's land-based missiles.

And that is their main deterrent. They have in addition negligible air-based nuclear power and some sea-based units. Their strategic submarines carry 2,178 nuclear warheads, against 5,760 for the US. The submarines themselves have limited sea-keeping qualities. They spend much of their time in port and are ``noisy'' when at sea.

The essential fact in the argument swirling around the preparations for the Geneva summit is that if the US perfects and deploys an effective nuclear defense screen, the Soviets will be right back where they started when President John F. Kennedy faced them down in the Cuban missile crisis. The missiles Nikita Khrushchev had intended to plant in Cuba went back home, exposed on the decks of the Soviets' supply ships for us to count and the world to see.

It was a major humiliation for a great power. Their answer was the deployment of the supermissiles, which by now give them ``equivalence'' in nuclear power.

Among Western physicists there is much doubt about whether star wars will work. But from the viewpoint of a man in the Kremlin, the essential fact is that the US leads the world in modern technology and has so far succeeded in achieving every major technical project it has set itself. It is the only country that can today send off space shuttles so regularly that any flight is now just a minor news event.

So while some American physicists are doubters, the Soviets are inclined to assume that what President Reagan proposes will probably come into existence someday. If that happens, a large part of their deterrent force will be neutralized and made meaningless in the world's balance of power.

That has one big meaning to them. It means that if they want to maintain ``equivalence,'' they will either have to negotiate a cancellation of the star-wars project or have to commit themselves to their own star-wars program, which would mean a second and even more extensive technical effort than they put into their SS-18 and SS-19 program.

They can do that, but it would probably mean cutting back on their civilian economic programs. Small wonder that they dislike star wars and want to block the project.