Cuban leader Fidel Castro has invited former U.S. president Jimmy Carter to visit his island the week of May 12-17. Carter and his wife Rosalynn will head a delegation that includes members of his Carter Center headquartered at Emory University in Atlanta, Georgia.

Anyone who knows Cuba is aware that the invitation comes at a time when Castro's 40-year-old dictatorship is falling on hard times. Last year, Cuba defaulted on some $500 million in loans. In March, Dutch authorities impounded one of Cuba's merchant ships in waters off The Hague to secure payment to numerous creditors. Following the terrorist attacks against America on September 11, tourism fell to such an extent that island hotels closed a third of their rooms.

Even relations with formerly friendly neighbors are turning sour. Last month, Uruguay became the first Latin American country to sponsor a resolution in the United Nations Human Rights Commission to condemn the regime's deplorable human rights practices. Even Mexico, once a defender of the revolution, has opted to refocus its relationship from Castro to the Cuban people.

This leaves Cuba's aging leader with few friends-outside of Iraq or Venezuela (both economic basket cases)-to turn to for a handout. That means going to that cynical architect of diabolical capitalism the United States to convince its Congress to lift the four-decade U.S. trade embargo-not so much to allow the regime to buy U.S. goods as to get access to taxpayer-backed loans.

Jimmy Carter is the perfect foil for such a gambit. Though known as a defender of democracy and human rights, the former president has a gullible streak and, like the Sunday school teacher he often resembles, looks for the best in some of the world's worst leaders. As president, he reportedly spoke of Yugoslavia's Marshal Tito as "a man who believes in human rights." In 1989, as an election observer in Panama, he had to be led by the hand to note the electoral frauds perpetrated by General Noriega's henchmen.

As an ex-president, he seems driven to conclude unfinished business from his own administration. During his presidency, the United States warmed to Cuba by agreeing to open what amounted to unofficial embassies-called interest sections. But Castro repaid that confidence with the Mariel boatlift that sent 125,000 Cubans, including violent criminals and mental patients, to America's shores. Will Mr. Carter use this opportunity to turn the other cheek?

In fact, the former President's trip has the potential to do a lot of good. If he truly wants to champion human rights, he could press Castro to release the rest of the regime's estimated 250 political prisoners including Dr. Oscar Elías Biscet, an Afro-Cuban who was imprisoned two years ago for displaying the Cuban flag upside down. Carter could participate in handing over a petition signed by 10,000 Cuban dissidents for granting civil liberties-known as the Varela Project-to the National Assembly.

He could ask independent Cuban journalists to accompany him on visits with dissidents-picked by him, not his state handlers. He could select some ordinary Cubans to take a meal with him at a fancy tourist hotel, which they cannot now do by Castro's laws that place tourist facilities off-limits. He could make a speech on Cuban television calling for Castro to respect the United Nations Universal Declaration of Human Rights and to lay the foundation for democratic reforms, as Generalísimo Francisco Franco did in Spain before he died.

But the former president could also do a lot of harm. For one thing, he could confuse human rights with economic privilege by lauding Castro's attempt to construct a decrepit welfare state at the expense of civil liberties. He might confess the imagined sins of U.S. countrymen in maintaining the trade embargo against a misunderstood dictator, thus embarrassing his own country. Worst of all, he could fawn over the scraggly Castro instead of reaching out to the rest of the island's 11 million citizens who must survive his crazy fantasies.

Whether President Carter will use this trip to advance the cause of liberty or allow himself to be manipulated by an aging tyrant remains to be seen. But the measure of success is clear. If he persuades the regime to begin respecting civil liberties and allowing Cuba's citizens to determine their own future, he will have succeeded. If he makes a plea for the United States to improve relations with the regime the way it is now, he will simply have wasted what could have been an opportunity to accomplish something constructive.

Stephen Johnson is a Latin America policy analyst in the Davis Institute for International Studies.