Nicaragua, seen in Washington as a menace to the United States, looks from here like a menace to human optimism.

This is the capital of the Sandinista revolution, a movement many in the Reagan administration -- like many Nicaraguans, especially the wealthier ones -- consider ominously left-wing: too close to Havana and Moscow, too much for comfort like a new Marxist-Leninist dictatorship in America's backyard. The United States is now waging clandestine war against the Sandinistas in a much-publicized CIA operation to destabilize the government here.

Presumably, the Reagan administration wants to push the Sandinistas in a direction more acceptable to the United States, or else to push them out of power, on the theory that if they don't change or disappear, their revolution will set a threatening example for all of Central America.

In the best tradition of American involvement in such situations, however, the clandestine war against Nicaragua is producing a result precisely the opposite of what was intended. American intervention has strengthened the Sandinistas at home, while giving them excuses to impose increasingly authoritarian controls on the population and to use Cuban advisers in large numbers. Nicaraguans who bitterly oppose the Sandinistas ridicule American policy as clumsy and counterproductive.

Even the American embassy reckons the Sandinistas would win a popular election today. (However, there won't be one until at least 1985, and there is no guarantee it will be genuinely competitive.) Although the domestic economy is slowly crumbling, the upper classes are fleeing like Frenchmen from Algeria and the revolution's attempts to improve living standards appear stalled, Nicaraguan and foreign observers here seem to agree that there is no prospect for a serious challenge soon to the nine men who comprise the Sandinista directorate that runs this country.

Welcome to Nicaragua, land of no evident hope.

This capital hardly looks like the headquarters of a menacing revolutionary movement. It hardly looks like a capital, either. Destroyed twice by earthquakes in the past 30 years, Managua is now a hodgepodge of buildings and shantytowns near the shores of beautiful Lake Managua. Across from the Intercontinental Hotel (where Howard Hughes once occupied the entire 8th floor), there is now a vacant lot that is occasionally used by Sandinista soldiers to play baseball, and occasionally by local sheep for grazing.

Like the Bolsheviks in 1917, the leaders of this revolution were largely members of the middle class claiming to represent workers and peasants. The government is now run largely by sons and a few daughters of the old bourgeoisie. Their policies are unabashedly tilted toward the poorest Nicaraguans, clearly (though not admittedly) at the expense of the small but articulate propertied class.

The government insists it is committed to a "mixed economy," pointing to the fact that 70 percent of economic activity is still in private hands. But well-to-do Nicaraguans say that two-thirds of the business people have already left the country, and government policy is squeezing out the rest. (This is not a wealthy oligarchy like the ones that have dominated other Latin American nations, but rather the Nicaraguan entrepreneurial class. In Nicaragua, the oligarchy consisted essentially of one family, that of former dictator Anastasio Somoza Debayle.) Much of the private sector consists of small farms.

Ideologists of the revolution, like the Panamanian Jesuit Rev. Xabier Gorostiaga, defend the notion of a mixed economy while calling for a new kind of "trickle-up" economics. This is official policy, and it inevitably means penalizing the few at the top, who started out with a better economic deal than the revolution thinks they deserve, while trying to improve the lot of the desperately poor mass of Nicaraguans.

The skills and resources of a few of the old bourgeoisie are needed by the government, so they are encouraged to stay. Most are not seen as necessary to the revolution, and they feel they are being pressured to leave.

A local manufacturer of pharmaceuticals probably will close his operation because the government can't or won't give him hard currency to import necessary raw materials. It is an ironic fact that the government can more easily import finished medicines -- using credits granted by friendly foreign governments -- than allow this local businessman to use scarce hard currency to import raw materials. So in the name of revolutionary independence, the Sandinistas are encouraging dependence on foreign suppliers.

Domestic industry -- always a small sector -- has shrunk dramatically and will be forced out of business, according to its proprietors. "The mixed economy will die by attrition," says a businessman at the headquarters of the Nicaraguan business organization called COSEP that the government still tolerates. On a wall outside its headquarters, a local graffiti artist has written: "Death to the Bourgeoisie."

Last year when leaders of COSEP wrote a letter to Daniel Ortega, president of the governing junta and a member of the revolutionary directorate, telling him how bad they thought the situation was getting, several of them ended up in jail for four months. Another leading businessman was shot dead by the security police under disputed circumstances. The government says the business community is tolerable as long as it stays out of politics. The businessmen ask how they can stay out of politics when the government won't let them conduct business.

Nicaragua has a famous dissident newspaper, La Prensa, whose proprietor was killed, probably by Somoza security forces, in 1978. The murder of Pedro Joaquin Chamorro was a key event in the history of the anti-Somoza revolution.

Today, members of the Chamorro family can be found on all sides of the revolution. Pablo -- the son of the assasinated Pedro Joaquin -- is editor of the Sandinistas' official newspaper. Xavier, Pedro Joaquin's brother, edits a newspaper that supports the government but is technically independent from it. The largest number of Chamorros, including the widow, another brother and another son of Pedro Joaquin, continue to run La Prensa, which actively opposes the Sandinistas but finds its critical articles invariably removed by the government censor, a 24-year-old woman lawyer.

The two Chamorros who are collaborating with the regime accept the idea of censorship as a necessary if undesirable element of the state of emergency declared last March in response to the Reagan administration's destabilization campaign. But those members of the family still running La Prensa attack censorship bitterly, and make clear their fear that Nicaragua is headed toward a Marxist- Leninist dictatorship. "I don't think they believe in freedom at all," says Jaime Chamorro, now the senior member of the family.

According to him and others at La Prensa, censorship has become stricter and more hostile in recent months. Routinely, they charge, the censor holds up production of La Prensa for as much as six hours, meaning that the afternoon paper sometimes comes out too late to reach its readers. The Chamorros recently showed a visiting group of American academics and journalists an editorial they had written criticizing the Cuban revolution as a model for Nicaragua's, recalling the Sandinistas' early commitment to democracy, human rights and a mixed economy. "If you see a photograph in this space tomorrow," one editor said, "you will know the editorial was censored." Sure enough, the next day's paper carried the photograph, not the editorial.

Government opponents have disappeared mysteriously since the revolution. Some, including a deputy minister of justice, have been arrested. An employe of the Red Cross was just sentenced to 20 years in jail as a CIA spy, though American embassy officials say he had no connection to the agency.

The government does depend heavily on Cuban advisers, and goes out of its way to court the Soviet Union. It abstained on the United Nations resolution most nonaligned nations supported that condemned foreign intervention in Afghanistan after the Soviet invasion. Revolutionary Nicaragua doesn't even recognize the Soviets' principal communist rival, the Peoples' Republic of China, but maintains relations with Taiwan instead. In recent interviews, two of the nine ruling figures here declined opportunities to criticize any aspect of the Soviet system.

Anyone who has spent time inside the Soviet orbit finds troubling signs here, from the way the censor blocks published criticism of communist countries to the defensive justification for the state of emergency offered by the leadership, to the double talk of apologists for the government who bandy about ideas like finding "a new meaning for the term 'political pluralism.' "

"What if The Washington Post sought systematically to overthrow the system of the United States?" asked Jaime Wheelock Roman, a commandante of the revolution and one of the nine key Sandinistas. "There would be two choices," he said. "The system would eliminate The Washington Post, or The Washington Post would eliminate the system." (The Chamorros' La Prensa "is against the entire system" and "against the revolution," Wheelock said.)

So there are ominous signs in Nicaragua. But a first-time visitor comes away with a more striking impression: None of what catches an American's eye in revolutionary Nicaragua could be called surprising. This is not, after all, an industrialized Western society. It is poor and backward, and never enjoyed any significant development of the social, economic and political institutions that make the advanced democracies work.

Much more important, this is a country that has been used and abused by the United States for most of this century. History is not a popular subject among American policymakers and politicians, of course. We "North Americans," as Latin Americans call us, would rather not accept responsibility for our past transgressions. In general, observed Miguel D'Escoto, the Jesuit priest who is Nicaragua's foreign minister and who is a U.S. citizen, Americans are "oblivious" to the history of U.S.-Nicaraguan relations. He is right.

Who recalls that the U.S. Navy first intervened in Nicaragua in 1910, a move that permitted an anti-government revolution that year to succeed? From 1912 to 1925 a permanent garrison of U.S. Marines helped maintain governments subservient to U.S. interests, while American bankers ran the country's central bank, collected its customs duties and ran the railroads.

There was trouble as soon as the Marines left in '25; in '26, 2,000 of them returned. They left in 1933, but only after creating a new Nicaraguan national guard led by Anastasio Somoza Garcia.

By 1936 Somoza had seized power. For the next 43 years, the original Somoza and his two sons brutally dominated Nicaragua, corruptly building a huge fortune while enjoying -- until almost the very end -- fulsome support from the United States. The Carter administration tried to establish better relations with the Sandinistas when they took power, but a combination of intemperate Sandinista rhetoric and behavior and Congressional opposition to U.S. aid sabotaged that effort. Then, at the end of 1981, the Reagan administration launched a clandestine war against Nicaragua, described as punishment for Nicaragua's support of leftist guerrillas in El Salvador. To conduct this secret war, the U.S. made alliances with disgruntled former members of Somoza's hated national guard.

Despite this history, the United States expects the new Nicaraguan government to be wary of Washington's enemies, and to embrace a North American version of liberal democracy and capitalism. In other words, we expect the Nicaraguans to be as oblivious to history as we are. You can argue that it would be best for Nicaragua if this were possible, but only the most stubborn dreamer could argue that this is possible.

Here is the fundamental U.S. dilemma in Latin America. We cannot make policy based on a realistic acceptance of the past -- this would be too masochistic, and would play into the hands of extremist anti-American forces, or so it seems. But if we try to make policy while ignoring the past, we produce profoundly unrealistic policies that leave us allied with reactionary regimes that no American would find acceptable in this country. In the end we are forced to ask the people of Latin America to accept conditions that we would never dream of accepting ourselves. We should not be surprised when they decline to go along.

Where is the Nicaraguan situation headed? In no happy direction. "What will happen?" said Commandante Wheelock. "First a war, then the total victory of the revolution at a very, very high cost. But it will end in revolution (throughout Central America)." Government officials here say they are certain that Washington will launch an overt attack against their revolution eventually. Visiting Americans can insist that this is most unlikely, but the Nicaraguans (prejudiced by history, perhaps) won't be persuaded.

And perhaps they don't want to be persuaded. Running a revolution is neither fun nor easy, particularly when your people are suffering from a crumbling economy. The presence of a scary foreign threat makes everything simpler; calls to sacrifice come naturally, as does popular cooperation.

Thomas Borge, the most colorful of the commandantes and reputedly one of the most radical, said he thinks the victory of revolutionary forces in Central America will actually be beneficial to the United States. Victorious revolutions would serve as "a tranquilizer to calm (America's) aggressive tendencies," Borge said, because once revolutionaries have taken control of the region, Washington will simply have to come to terms with them. The only available option will be a more realistic U.S. policy, Borge predicted.

There are other possibilities. Even if the Sandinistas are determined to create a Marxist-Leninist state in Nicaragua (and that is possible, though not proven), they are afraid to move quickly in that direction. They know the Soviets are not prepared to underwrite another Cuba. They know their own countrymen took seriously their promises of democracy. They know that La Prensa sells more copies than the two newspapers that support the government, even if they are confident of broad national support, particularly from the young people who are a majority of Nicaragua's population.

The United States could actually make life more difficult for the Sandinistas by ending its campaign against them. Without a foreign devil to unite the country, the revolution would be judged internally by a different standard. It might even be pushed in a different direction.