The Caribbean: a flash point in heated US-Soviet relations

In the wake of the United States intervention in Grenada, Washington and Moscow are sizing each other up - and waiting for the competing superpower's next move in Latin America.

Such moves could include:

* Direct US armed intervention in Nicaragua.

* Or, a major upgrading of the Soviet military presence in Cuba.

* Or, the stationing of more Soviet submarines in the Caribbean, carrying nuclear missiles targeted at the US.

This seems to be the composite view of both American and Soviet officials, interviewed both before and after US marines landed in Grenada.

(Uncertainty hung over US-Soviet ties amid speculation that President Yuri Andropov, not seen publicly since mid-August, was seriously ill.)

Some of these scenarios, for the time being, seem unlikely. The US has denied that the military intervention in Grenada was a ''trial run'' for an invasion of Nicaragua. And the Soviets have ruled out attempts to place land-based missiles in Cuba - although they have not ruled out some other way of stepping up Soviet military presence there.

What is a distinct possibility, according to Western observers, is stepped-up Soviet submarine patrols off the US mainland.

But even this move is played down by some Soviet and American officials. These officials say they wish to avoid a head-on clash in the region similar to the Cuban missile crisis of 1963.

''I personally lived through that very dangerous period of the Caribbean crisis,'' says a Soviet official. ''No one in our country would want to pass through it again.''

Nor would many US officials, albeit for different reasons. The face-off between President John Kennedy and Soviet leader Nikita Khrushchev - which ended in a humiliating backdown for the Soviet Union - gave added impetus to an unparalleled Soviet military buildup.

Still, the military here has vowed that the Soviet Union will retaliate for the deployment of new US missiles in Western Europe, which is scheduled to begin this December. Already, the Soviets have announced that one countermeasure would be additional Soviet missiles in East Germany and Czechoslovakia.

But the Soviets also have indicated that they might take further steps. Specifically, they point out, the American Pershing IIs to be deployed in West Germany could reach the Soviet Union in about 10 minutes. The demands of strategic balance, some Soviet officials argue, require that the USSR be able to pose a similar new threat to the US.

But Soviet officials say they have ruled out the possibility of placing nuclear missiles in Cuba. As an official here said recently, ''We will do nothing to cause security problems for our friends in Cuba.''

That, in the view of many analysts, leaves only two major options open to the USSR if its threat of retaliation is to be carried through. One is to place new land-based missiles in the far eastern part of the USSR, where they would be within striking range of Alaska and several states in the Northeastern US. The other possibility - and the more likely one, in the view of some US analysts - is the stationing of submarine-launched cruise missiles somewhere off US shores, probably in the Caribbean.

Meanwhile, some Soviet officials profess to see ''four or five points of tension'' in the Caribbean and Latin America that offer the potential for East-West confrontation in the region. These are:

* El Salvador. The US is supporting the Salvadorean government against insurgents who are reportedly backed and supplied by the Soviet Union and Cuba.

* Nicaragua. The US is backing insurgents who are trying to pressure, if not topple, a government backed by the Soviets and Cubans.

* US-Cuban relations.

* The Falkland Islands. This territory, over which Britain and Argentina fought a war in 1982, remains ''a potentially dangerous spot,'' says a Soviet official. ''The problem hasn't been resolved.''

* Chile. The embattled military government of Gen. Augusto Pinochet is facing increasing domestic unrest. ''The days of the Pinochet regime are coming to an end. There will be a change in this particular country,'' the official said.

Whether any of these views give an indication of likely future moves by the Kremlin remains to be seen. But what does seem apparent is that there are two fundamentally divergent - and perhaps irreconcilable - views in Washington and Moscow over the significance of events in the Caribbean and Latin America.

One official says the USSR favors the resolution of the problems of the region through ''political means.'' On further questioning, however, he conceded that ''political means'' could include ''national revolution.'' But, he says, such events are purely internal matters that should not concern the US.

''To use one of your expressions,'' says a Soviet official, ''the US should 'let sleeping dogs lie.' ''

US officials claim that American policy is merely to stop the flow of arms - and the export of revolution - to neighboring countries from Nicaragua.

But US officials see the Soviets and Cubans behind much of the regional unrest and make it clear they take Soviet moves seriously.

A US official, quoted by Reuters, said events in Grenada were the result of ''low-level probes . . . in areas ever closer to vital US interests.''