On the eve of its 50th anniversary, the Cuban Revolution -- or what is left of it -- can contemplate a bewildering paradox that sums up the results of one of Latin America's most daring political feats of all time. Never before has Havana harvested diplomatic successes of the sort it has enjoyed in the last few months. Yet never before has the survival of the regime -- and the Cuban people's acceptance of the domestic sacrifices it demands of them -- been so much in doubt.

This is not what Fidel and Raúl Castro, nor Che Guevara, had in mind when they swept down from the Sierra Maestra as 1958 ended, or when they began their triumphal march across the island, as 1959 began. It is in this contradictory context that the Obama administration will have to define its Cuba policy.

In recent weeks, Cuba has hosted Russian President Dmitry Medvedev and several Russian navy ships, rebuilding the relationship that collapsed in the early 1990s. It received the visits of Chinese leader Hu Jintao and Brazilian President Luiz Inácio Lula da Silva. In Brazil last week, Cuba was admitted, at Mexico's initiative, to the Rio Group, an ad hoc assembly of Latin American nations created in 1986 to support a negotiated peace in Central America. The group had traditionally considered representative democracy and respect for human rights to be preconditions for membership. Raúl Castro, who has managed to eliminate nearly all foreign scrutiny of human rights and democracy in Cuba, is preparing a trip to Vietnam, where he will tout the similarities between his ambitions for Cuba and Vietnam's own stance: moving toward a market economy that provides a higher standard of living for its people without relinquishing an iota of power embedded in one-party rule.

Lastly, but perhaps most importantly, the Castro brothers have convinced almost every Latin American government that the main item on the region's agenda with Barack Obama is the suppression of the U.S. embargo with the island. For a country that only five years ago was isolated in the hemisphere, condemned for human-rights violations by the United Nations and had its ties with the European Union virtually suspended, these are no minor accomplishments. But they seem rather pale when placed in the light of the enormous challenges and difficulties the Cuban people face in everyday life, now more than ever. Three of them deserve special mention.

First, of Cuba's roughly $11 billion in yearly foreign-exchange revenue, the $2.5 billion from nickel exports is plunging because of falling commodity prices; an additional $2.5 billion from tourism is also dropping because of poor services and the world-wide fall in vacation spending. The remaining $6 billion springing from the export of so-called professional services, that is, the revenue generated abroad by renting doctors, nurses, teachers, security and intelligence personnel, as well as everyday handymen, to countries such as Venezuela, Ecuador, Bolivia and now Paraguay, will also diminish, since the payer of last resort, Venezuela's Hugo Chávez, has suffered a precipitous fall in his own oil-based income.

Secondly, this fall's hurricanes wrought enormous damage in Cuba, mainly in housing and agriculture. Havana's authorities once again showed their prowess in evacuating large swaths of the population, but the natural disasters also demonstrated in what shambles the country's infrastructure and countryside find themselves in. Consequently, doubts about whether the Cuban people will continue to endure the adversities brought about by the shortfall in hard currency, the lack of foreign credit or investment, the damage done by the hurricanes and the overall disaster the economy lives in, seem greater today than at any other time, even than in the mid-1990s when the subsidy from the Soviet Union evaporated.

But most importantly, Fidel Castro's unending battle for life leaves too many questions unanswered. No one knows how deep his younger brother's intentions of economic reform are, since the elder Castro will not really countenance them while he still breathes. And no one can predict whether the Cuban people will continue to make the enormous sacrifices they have already faced, when it is no longer Fidel doing the asking, but rather his uncharismatic, technocratic and unpopular brother who must show up at protests and food riots and talk the people down.

Barack Obama will have to deal with this mess. He faces a tough choice. A growing number of Latin American governments are, out of conviction or opportunism, befriending Cuba. Only a full-fledged economic normalization of ties with the U.S. will alleviate Cuba's suffering in the short and medium term. So which will it be: listening to Latin America but propping up the existing regime? Or negotiating political, if not regime, change with the Latin Americans, in exchange for normalizing economic ties?