Moscow finds its nuclear umbrella a comfort in any storm

Yuri Andropov tried to perform a difficult feat this week. He and his Kremlin viziers sought to portray Ronald Reagan as the world's leading hawk while themselves threatening once again to deploy more nuclear missiles in Eastern Europe if NATO tries to match present Soviet-bloc missiles with Pershing IIs and cruise weapons.

Why did they run the risk of rattling their SS-20s at a time when Mr. Andropov is trying to woo European doves? Why did they rattle missiles at a moment when Mr. Reagan himself was having to make a belligerent-sounding move in Lebanon?

The simple explanation is that the Kremlin was hoping to divert world opinion from further thought about the Korean passenger plane shoot-down. Or that Andropov's colleagues were trying to quash rumors that they were softening their Geneva arms control position because of bad publicity over the plane incident.

But there is probably a more basic reason for Moscow's move. It has to do with the vital role nuclear missiles play in bolstering the Kremlin's claim to equal status with the United States as the world's other superpower. Without nuclear missiles, Moscow would not be to America what Sparta was to Athens, Portugal was to Spain, Napoleonic France and then Germany were to Britain.

Nuclear weapons serve as the great equalizer for Moscow. In other areas - economic, technological, ideological, and the global use of conventional military power - much of the world perceives the West-plus-Japan to be well ahead of the Soviet Union. But, under the USSR's growing nuclear missile umbrella, the Soviet Politburo can make maximum capital of its military forces in Europe and in selected spots in the third world.

So the Kremlin leaders find it useful to remind the West and themselves of their nuclear equality. It is particularly reassuring at times when other things aren't going well - world opinion, their satellite empire, management reform and labor productivity at home, growth of their economy, the computer technology race, even Angola and Ethiopia.

This week Washington unwillingly helped provide cover for the Soviet belligerence by sounding belligerent itself on Lebanon. President Reagan's order allowing carrier-based air support for US marines in Lebanon is a calculated risk. It seeks to fend off Soviet meddling in Lebanon by way of Syria. But it runs the risk for Mr. Reagan that he can be painted before both American and European public opinion as escalating toward another Mideast war.

Soviet propaganda is doing its best to say that either (1) the Korean plane incident was the fault of the US or (2) the Soviets were just doing what a superpower like the US does on other occasions. That approach is intended to cement the idea that superpowers don't behave the way others do because they have larger responsibilities. Then, to make sure public opinion knows the good guy from the bad guy, Mr. Andropov's film critics are trying to put a black hat on Mr. Reagan for his actions in Nicaragua, Lebanon, and on NATO missiles.

The most damaging thing that can happen to the US President's moral authority is for him to be seen - particularly in Europe - as just as hawkish and inflexible as Kremlin leaders.

Last week Soviet bureaucratic-military muddling over Sakhalin left a clear moral distinction, with Mr. Reagan wearing a white hat. But that clarity may now be blurring in Europe as events unfold elsewhere.

To some extent, Mr. Reagan is having to wrestle with the residue of the Haig era in foreign policy. Haig-Reagan inaction at the time of the Israeli invasion of Lebanon has led to the current situation where marines face not only warring factions in that country but, potentially, Syrian forces with Soviet advisers and equipment. And General Haig's high-visibility intervention policy in El Salvador-Nicaragua helped to rivet European public attention on every US move in that region.

This leaves a dilemma for President Reagan. If he sounds very tough to reassure his own followers at home, he will cause more trouble for his allies abroad - specifically Helmut Kohl in Bonn.

Furthermore, if he sounds too hawkish on issues like Central America and the Mideast, he will help Mr. Andropov divert world attention from the growling bear. And he will incidentally help Mr. Andropov marshal patriotism at home around the theme of the ''sacred soil'' of the USSR. Andropov needs that kind of patriotic rallying if he is to get anywhere in his attempts to reform the work habits of Soviet labor.

Contrary to the general impression in the West that Soviet workers are assigned for life to a single workplace, actual turnover of labor in Soviet plants is about 20 percent per year. That compares with only about 3 percent in the US. As Andropov pointed out shortly after taking office, absenteeism and malingering are among the chief reasons for that turnover - and for a productivity rate that is not far from dismal in what is supposed to be the ultimate workers' state.

Ironically, Mr. Reagan is using the American patriotism stirred by the Korean plane incident to push military rebuilding programs which may harm American productivity in the long run.

Mr. Reagan cites Soviet behavior over the Korean incident to persuade Congress to continue funding his defense buildup, including the expensive ''star wars'' missile defense program. As is often noted, such expenditures - unless accompanied by big cuts elsewhere in the budget or by new taxes - will siphon off capital needed to make American industry more efficient. Without capital for new plants in many older industries, US productivity is not likely to grow.

So the combined Lebanon-Euromissile-Central America tension is causing harm in several ways. It appears, among other things, to have slowed once again talk of a summit - or at least progress in the Geneva arms control talks.

But for all the tension in the air since the Korean plane incident, there appears to be no reason for the public to be overwhelmed by fear. As post-Hiroshima crises go, the current series of superpower problems is less explosive than many earlier ones. The Korean war crisis; the 1956 Soviet invasion of Hungary coupled with the Anglo-French-Israeli Suez invasion; the Cuban missile crisis; the Soviet-Chinese border crisis; or certain touchy stages of the Vietnam war - all created greater danger of superpower collision.

In fact, behind the hawkish noises, there are some almost unnoticed signs of progress on the international scene:

* Iran is quietly beginning to trade again with the West - albeit not America. The revolutionary Jacobins in Tehran have begun to deal with Japan, Germany, and Italy in what a specialist points out as a move remarkably similar to Lenin's New Economic Policy of 1921. At that time the revolutionary fervor of the Russian Bolsheviks was not working economically and Lenin turned to trade and investment from the capitalist West. Iran's Islamic ''bolsheviks'' appear to be taking the same tack.

* Mexico has made a remarkable comeback as a result of its first year of austerity. It has restored a favorable balance of trade and cut inflation from 100 percent to under 80 percent.

* In Angola, territorial gains by rebel leader Jonas Savimbi increase pressure for a settlement that would remove Cuban (and Soviet) influence. And Angola's East African counterpart, Mozambique, appears to be moving away from Soviet trade ties back toward the West.