WASHINGTON - Czech diplomats will say only that the two 30-foot radio antennas looming behind their embassy in the lush Rock Creek Park neighborhood are used primarily to communicate with Cuba.

But it's unlikely that they are used to contact the Cuban government.

Once a subservient member of the Soviet bloc, the Czech Republic is now one of Fidel Castro's top foreign tormentors, providing material and moral support to dissidents, leading efforts to condemn the island's human-rights record in U.N. bodies and pushing a reluctant European Union to take a tougher stance on Castro.

Such actions have earned the tiny nation of 10 million vitriolic condemnations by the Castro government, the harassment of its diplomats in Havana and the gratitude of the Cuban-American community.

''The Czech Republic is at the heart of the U.S. efforts to secure multilateral support for precipitating a transition for democracy in Cuba,'' says Miami Republican Rep. Ileana Ros-Lehtinen. ``They've stuck to their principles every step of the way. Thank the Lord for the Czech Republic.''

SENSE OF KINSHIP

And lately the Central European nation seems to be devoting more resources to the cause. Besides the antennas, believed to be beaming pro-democracy broadcasts to Cuba, the embassy has a full-time Cuba desk officer and is distributing pro-democracy literature on the island, said Czech Ambassador Petr Kolar.

The 44-year-old Kolar, who worked as janitor in the 1980s after he was ejected from a university for refusing to join the Communist Party, and more recently oversaw a human-rights division in the foreign ministry, said Czechs have a sense of kinship with the Cuban opposition.

''After the fall of communism, it became our natural duty to help people in countries where they have authoritarian or totalitarian regimes,'' he told The Miami Herald. ``We remember how important it was to be supported from outside.''

That history gives unique legitimacy to the Czech efforts on Cuba, as well as a sense of what might work best to undermine a communist government.

To mark the anniversary of a harsh 2003 crackdown on dissidents, a nongovernment group set up a mock Cuban prison cell in Prague's central Wenceslas Square in March. Foreign Minister Cyril Svoboda donned a striped prison uniform and spent a brief spell in the cell to highlight the dissidents' plight.

UNFLATTERING PHOTOS

More recently, Czech supermodel Helena Houdova slipped into the island and took photos of Cuban slums. Police detained her for 11 hours, but she managed to smuggle out the camera's memory card in her bra -- creating a media stir in Prague and later displaying the photos in an exhibit.

''The revolution's watchmen rose up because I was taking pictures of something they do not like,'' the 1999 Miss Czech Republic told journalists.

Vaclav Havel, the former playwright who became president after the collapse of communism, has continued a high-profile push for more international condemnation of Cuba after leaving the presidency in 2003.

To protest the 2003 crackdown, he founded the International Committee for Democracy in Cuba, whose members include the Czech-born former U.S. Secretary of State Madeleine Albright, former Chilean President Patricio Aylwin and former Spanish Prime Minister José María Aznar.

Havel also is a partner in the Czech democracy-promotion group, People in Need, which receives support from the foreign ministry, as well as U.S. groups funded partly by the U.S. government. Since its creation in 1992, the group has provided medical and office supplies to Cuban dissidents.

The Czechs also are working to disseminate information to the Cubans, echoing similar U.S. efforts, that include literature on their own transition to democracy after the so-called Velvet Revolution, a peaceful uprising of street protests that brought down communism in 1990, Kolar notes.

''From that point of view, our country and some other countries from our part of the world are a very bad message for Mr. Castro,'' Kolar said.

Czech diplomats also have been active in attacking Cuba's human-rights record before the United Nations. In 1999, they won passage of condemnation of Havana at the U.N. Human Rights Commission, reversing a U.S. failure to pass a similar resolution the year before.

And shortly after joining the European Union in 2004, the Czechs defeated a Spanish effort to bar European embassies in Havana from inviting dissidents to their national-day cocktail parties.

Kolar said his government also will push the EU to create more effective instruments to support democracy in Cuba.

CASTRO: `U.S. PUPPETS'

Castro has called Czech government officials ''toadies'' and ''U.S. lackeys.'' A May 9 editorial in the Communist party newspaper Granma called them ``salaried puppets of the imperial circles of power in the United States and of the anti-Cuban Miami terrorist mafia.''

In 2001, two Czech Parliament members, Ivan Pilip and Jan Bubenek, spent 25 days in a Cuban jail before they were expelled. And last year a Czech senator and other EU officials were expelled after they tried to attend a dissidents' convention.

Kolar said Czech diplomats in Havana are under constant surveillance. Electricity and water to the mission were cut for a few days last month, mirroring a similar measure against the U.S. diplomatic mission to Havana.

Cuban officials have confiscated Czech-provided laptops and other materials destined for dissident groups, Kolar says, and in October barred the Czech Embassy from celebrating its national day in a hotel, because it had invited dissidents.

DIPLOMAT EXPELLED

In April, Cuba ousted Stanislav Kazécky, a diplomat, on accusations of spying.

Dan Erikson, a Cuba expert with the Washington-based Inter-American Dialogue think tank, said the Czech policies on Cuba can be explained in part by the country's own history of a dissident movement that successfully opposed communism.

''Every country in Europe tends to see the Cuban experience through their historical lens,'' said Erikson.

LONELY VOICE IN EU

But he added that other countries, especially in Western Europe, don't share the Czechs' passion for what happens in Cuba and mostly view the U.S. embargo on Cuba as wrong.

The Czechs do not condemn the embargo publicly but vote against the sanctions at the United Nations.

Still, the Czechs have made Cuba a ''much more contentious issue'' within the EU, says Erikson, making the union more likely to support dissidents on the island.

Kolar also argued that a small nation such as the Czech Republic, formerly part of Czechoslovakia, which was annexed by Nazi Germany in 1938 and overrun by Soviet troops at the end of World War II, has to have an activist foreign policy.

''We have to be active in international affairs,'' Kolar said, ``because when we were not, we were swallowed by big powers.''