THE INCIDENT at the Peruvian embassy in Havana is as close as Cuba ever gets to a free election. Peru had given asylum to a few Cuban "dissidents" who had crashed through the guard their government posts around foreign embassies to keep common citizens out. Fidel Castro then lifted the guard, apparently figuring to teach Peru a lesson by allowing a certain number of Cubans to enter and swamp the facilities. But in barely a day, upwards of 10,000 Cubans flooded through, creating a logistical nightmare but meanwhile dramatizing the level of desperation and discontent among the Cuban people. For nothing more than the hope of leaving -- a hope that, if frustrated, would leave them vulnerable to the state's vengeance -- these people were ready to abandon their whole stake in their homeland and take a chance in a foreign land.

The Castro government promptly and typically characterized the 10,000 as "anti-social elements, vagrants and bums" and bid them good riddance. Yet the incident casts a rare, revealing light on the 20-year record of communist Cuba, so often portrayed by sympathetic visitors as a proud and plucky little country that plays David to the imperialist Goliath and provides working mothers good day care to boot. The judgment reflected at the Peruvian embassy is of a country that offers such an unpromising future that, the instant an opportunity appears, 10,000 people are ready, at great risk, just to go.

So much for the popular appeal of Castroism -- day care or no. Economically, socialist Cuba is even more colonially dependent on a single export crop than pre-Castro Cuba. A Soviet subsidy, not the performance of the system, keeps socialism afloat in Havana. In return, Moscow gets a Caribbean outpost and rents the Cuban army.

Such is the substance of the "Cuban model" that Fidel Castro and his admirers hold up for emulation by Latins and others. Cuba is a police state whose impoverishment is scarcely concealed by foreign subsidy and whose assertive nationalism in turn conceals a status as a great-power pawn. At a time when ferment in Central America and the Caribbean has stirred fresh awareness of Cuba's capacity for trouble-making, it is sobering to see 10,000 Cubans making the point.