The stage is being set for the next Cuban confrontation even before U.S. and Soviet diplomats work out the solution to the crisis over the so-called Russian combat brigade.

The next act will focus on whether or not Soviet submarines and warships have violated the understandings reached by the two superpowers in settlement of the 1962 Cuban missile crisis. Those agreements, which have never been made fully public, are supposed to bar the Soviets from introducing offensive weapons into Cuba in return for a U.S. pledge not to invade the island.

In 1970, after concern developed that the Russians were building a submarine base at Cienfuegos Bay, President Nixon announced that port calls in Cuba by Soviet submarines and ships would not violate the agreements, but servicing such vessels "either in or from Cuba would be a violation."

The next crisis is expected to develop around the servicing of Soviet ships -- a violation of the Nixon interpretation. The scene will be the newly constructed naval facilities and deep-water pier recently completed by the Cubans under Soviet supervision at Cienfuegos Bay along Cuba's southern coast. The main players will be elements of the Soviet navy, most probably one of the two annual ship deployments that have taken place in the Caribbean every year since 1969.

Last fall, a fleet of five Soviet ships spent 82 days in the Caribbean, more than twice the normal length of time for such deployments. The ships transited the Gulf of Mexico, stopped at Havana and then, for an amazing 65 days, remained at anchor just outside Cienfuegos Bay. "Hanging at anchor," according to a Pentagon intelligence analyst, is typical of Soviet navy deployments all over the world.

With U.S. intelligence agencies watching and listening, the only support the Russian ships received from the mainland was food and water -- permissible replenishments under the port-call concept. Refueling and other servicing of the Soviet vessels -- a guided-missile destroyer, two guided-missile frigates, a conventionally powered attack submarine and an oiler -- were carried out by Russian ships.

U.S. intelligence analysts say the Cienfuegos facility was not ready to receive ships last fall. Last spring, when the first of 1979's Soviet navy deployments took place, the ships bypassed Cuba altogether after publicity in the U.S. press called attention to the possibility that a violation of the 1962 agreements might be in the offing.

It is doubtful that the Soviets will continue to avoid going into Cienfuegos in the future.

Since 1970, they have shown a desire to have a naval facility at Cienfuegos. That year, when the Nixon administration determined construction was under way for a facility for Russian vessels, it called in Soviet Ambassador Anatoly Dobrynin and protested. After an exchange of meetings, Nixon announced his understanding about the 1962 agreement as it applied to ships, and the Cienfuegos construction stopped.

In 1972, however, just weeks before the Moscow SALT I summit, the Soviets sent one of their diesel-powered ballistic missile submarines -- a Golf II, which normally carries three SSN5 3.5 megaton nuclear missiles -- to call at a Cuban port where it rendezvoused with a tender and other Soviet ships. The United States did not protest, since the Nixon 1970 understanding permitted port calls, even by missile-launching subs.

Another vist was made by a Golf II in May 1974, in the midst of the impeachment uproar. Again, no protest was made.

Both visits were announced by the Pentagon, and no public or political protests were registered.

During the SALT II hearings last July, Sen. Richard Stone (D-Fla.) raised the Golf submarine visits to Cuba almost as often as he spoke of the presence of Soviet troops. Thus, the carter administration cannot count on the same free ride on the issue that the Nixon administration got in 1972 and 1974.

The White House can hope that, with tensions as they are, the Soviets will forgo having their subs and warships call in Cuba, at least until SALT II is passed or voted down by the Senate.

But there is no doubt the issue will eventually come up again. For one thing, the Soviets are expected to continue to send their growing naval forces into the Caribbean, much as we continue to send destroyers twice a year into the Black Sea.

The Russians, however, have a second impetus. Cuba has always offered them the opportunity to do to the Americans what they felt had wrongly been done to them for years.

As Nikita Khrushchev put it when discussing the 1962 Cuban missile crisis in his book, "Khrushchev Remembers": "The Americans had surrounded our country with military bases and threatened us with nuclear weapons and now they would learn [with the proposed installation of missiles] just what it feels like to have enemy missiles pointing at you . . . . It was high time America learned what it feels like to have her own land and her own people threatened." l

That feeling has never left the Soviets, though they gave up the missile idea in 1962. Thus the Carter administration would do well to anticipate what's coming, make clear what the Nixon administration accepted in the past and determine what its reaction will be when Soviet ships or submarines finally tie up at the Cienfuegos pier.