For weeks now we have been exposed to the tragic spectacle of thousands of Cubans desperately trying to flee the island. The human aspect of this tragedy has been aggravated by Carter's hesitation as well as by Castro's frantic maneuvering and viciousness.

Little can be added to the human side of the story. Faces and events speak more eloquently than words. But there is a meaning behind those events that could confront the United States with an opportunity that transcends the boundaries of Cuba and the refugee issue.

Underneath the bragging and the orchestrated mass demonstrations, Castro is running scared. The Soviets may move to free themselves from the discredit he is heaping upon the socialist model among Third World leaders. They may be concerned with a Caribbean Afghanistan. Furthermore, these events show that Castro has lost touch with Cuban public opinion.

The action that unleashed this situation was Castro's decision to allow visits by exiled Cubans. Instead of treating them contemptuously as "worms," Castro's press called those who had fled the island "members of the community in exile." His main concern was to earn desperately needed foreign exchange. Overconfident, as all beneficiaries of absolute power are, Castro could hardly expect that move to bring so many headaches upon his regime.

The 100,000 Cubans who visited the island in 1979 had an eye-opening impact on those who had stayed behind. The contrast in life styles awakened memories among the old, who could remember. It also opened new vistas to the young, who supposedly were thoroughly indoctrinated by the regime. The impact was not limited to the appeal of abundant food, clothing and electronic gadgets, but went to the deeper issue of freedom. There is a stronger appeal in being able to speak, to travel and to live and work where you want. And, most important, people want to be free of fear.

To say this does not belittle the importance of material conditions. These mass visits coincided with a disastrous situation in the Cuban economy: the collapse of the tobacco crop forced the closing of cigar and cigarette factories, idling 27,000 workers. The sugar crop this year is also a failure. Consumer goods shortages are appalling. The so-called Soviet assistance does not seem to alleviate those hardships.

In the presence of an increasingly educated population, it is easy to understand the judgment of those who want to leave. Cuba under Castro is unable to offer the good life or the pursuit of happiness. Charisma is no longer enough to keep the population's support for the regime.

In a speech last December, Castro made a pessimistic review of the economic situation. Earlier, his brother, Raul, minister of defense, had blamed the revolutionary leadership -- meaning Fidel -- for the economic mess. Castro took over direct supervision of the Ministries of Defense, Interior, Culture and Health -- a strange approach to improve the management of the economy. More likely he was trying to prevent a Soviet move to replace him or to regain control of the police and military from pro-Soviet elements.

In January 1980, Celia Sanchez, Castro's Sierra Maestra secretary and lifelong companion, died. This provoked speculation in diplomatic circles in Havana that she was killed in a shootout between Fidel and Raul. Since Raul is known to be the Soviets' preferred Castro, it is not too farfetched to infer that Soviet pressure is a cause of tension among the core leadership in Havana.

Pressure for what? We can only speculate. The Soviet Union cannot be too happy with Castro's failure to use his position as chairman of the non-aligned movement to ease its embarrassment over Afghanistan. In fact, Castro couldn't even attend President Tito's funeral. At a time when the Soviets see opportunities in the Caribbean, Central America, Africa and the Middle East to capitalize on a favorable military balance of forces, Castro's clumsy handling of the Peruvian Embassy incident has introduced an unnecessary and most damaging distraction. What has happened undermines the rationalizations used by the Soviet Union to justify its expansionism in the Third World.

Rather than Cuba's being seen as a model for the wave of the future, questions are being raised in Mozambique, Jamaica, Guyana, Costa Rica, Peru and other quarters about the workability of the Cuban experiment. No wonder Castro wants all the refugees to come to the United States instead of going to Latin America. There they could help destroy the myth of his success in building a new, happier society.

The use of goon squads at the U.S. Embassy against those wishing to leave and the announcement on May 1 of the creation of a militia seem to reflect Castro's distrust of the Cuban armed forces. It is not that they may be unwilling to act against the people; that point has not yet been reached (although it may come, as it did it Hungary in 1956). Probably Castro needs a force less influenced by the Soviets to protect himself from a fate similar to that of Hafizullah Amin in Afghanistan.

In the event of disintegration of the Castro regime, what should our position be? We must be prepared to face the eventuality of a Soviet move to replace Castro in order to keep Cuba within the communist camp. Even if severe repression is required, the Soviet military leaders are unlikely to accept quietly the loss of such a crucial strategic position. Following usual Soviet practice, Castro's adventurism could be blamed for the regime's failure.

Under such circumstances, could the Soviets rely on the Cuban armed forces in Cuba, Ethiopia and Angola? That is doubtful. Once events are unleashed, the hatred of the Cubans for the Soviets will make the regime highly unstable. As in Hungary, Czechoslovakia and Afghanistan, Soviet forces may have to be used. That is the moment for which we had better start preparing contingency plans and, one hopes, under a more determined leadership than we have shown recently.

Granted, this is a very hypothetical interpretation of the meaning of the Cuban exodus. But we should not ignore it. Guilt over Vietnam, Chile and Watergate has made many lose sight of the strong appeal of a free society. It is that kind of attitude that leads people to think that communism is irreversible, but not even Brezhnev believes that. If he did, the Brezhnev doctrine would not have been necessary.