ECONOMIC crisis threatens the survival of Fidel Castro's communist regime in Cuba. New noncommunist governments in Eastern Europe have cut economic ties with Cuba. The Soviet Union is ending the special relationship that Cuba long enjoyed.The Cuban economy is in dismal shape and remains deeply dependent on the Soviet Union, which still accounts for more than 70 percent of Cuba's trade. Over the past five years, Soviet aid accounted for 20 percent of Cuba's national income and 90 percent of its fuel supply. In 1990, Soviet aid declined by 30 percent and oil shipments by 25 percent. These trends have continued in 1991. Russian President Boris Yeltsin called last month for the end to all aid and subsidies to Cuba. Shrinking aid and trade, co mbined with the economic failures of communism, have led to shortages of food, energy, and nearly all consumer goods. The decline in Soviet aid is bankrupting Cuba. Faced with the possible termination of all Soviet subsidies, Castro recently announced severe austerity measures. Gasoline consumption will be cut 30 to 50 percent, electricity usage will be reduced by 10 percent, and more food items will be rationed. The end of Cuba's special relationship with the Soviet Union raises questions of whether Castro will survive. Many analysts predict that worsening discontent in Cuba will bring him down. Before the recent coup in Haiti, Castro was the only leader in Latin America not democratically elected. He has rejected economic and political reform and continues repressive policies. Castro's days are numbered, but he may last longer than some people think. It is possible that his regime can scrape through for a few years. Even his opponents point out that no one starves or goes barefoot in Cuba, education and basic medical care are universal, and crime is low. So far, Castro's domestic opposition has been weak and easily contained by security forces. Continued anti-Castro statements from the US give him a foreign enemy and an excuse to demand further sacrifices from the Cuban people . The end of the cold war and the collapse of communism in the Soviet Union and Eastern Europe offer an opportunity to reassess US policies toward Cuba. The US wants internal change in Cuba, but the major source of tension in relations always has been Cuba's close ties with the Soviet Union. Now that the Soviets no longer export revolution to the third world, Cuba's role as a Soviet proxy has vanished. Cuban troops have come home from Africa, and the Soviets plan to remove their troops from Cuba. This poor and isolated country no longer threatens anyone but itself. Whether Castro lasts another three months or three years, Washington should begin to think about post-Castro Cuba. Better relations between the US and Cuba would reduce regional tensions, promote economic development in the Caribbean, and provide the US with a valuable trading partner. I do not think it is possible for the US to have normal relations with a Castro-led Cuba, or to lift the economic embargo so long as Castro remains in charge. Nonetheless, we should begin to discuss issues of specific interest to us. To the extent that Cuba accommodates the US on issues such as immigration, drug trafficking, and support for rebels in Central America, we should take modest steps to improve relations. We should also permit travel to Cuba and a wider range of personal exchanges. If we hope to influence change in Cuba, we need to increase our dialogue and engagement with the Cuban people, especially the youth. President Bush has properly rejected any US military move against Castro. A more aggressive policy would disrupt US relations with Latin America, lend credence to Castro's propaganda, and give him an excuse for domestic repression. The US should, however, step up international political pressure on Castro. We should demand free elections, supervised by international observers. We should do all we can to make Castro accountable to the Cuban people, and let them decide whether he stays or goes. It would be far better for the future of US-Cuban relations if Castro were removed peacefully by his own people rather than by forces from abroad.