Cuba marks the 50th anniversary of its socialist revolution today. What's to celebrate?

First and foremost, the revolutionary faithful will surely toast their own survival. Fidel Castro and company have withstood American challenges spanning 10 presidencies: the failed Bay of Pigs invasion, covert actions and five decades of economic sanctions. Against all odds, they also survived the collapse of the Soviet bloc, which plunged Cuba into a near-starvation economy in the early 1990s, when output shrunk by one third.

They will celebrate Cuba's outsized role in the world, marked by deployment of troops in Africa and the Americas during the Cold War, and by deployment of more than 50,000 doctors, nurses and teachers in 96 countries today. They may raise a glass to Cuban diplomacy, which has built new economic partnerships with Venezuela, China, Russia and Brazil, and has prompted all the countries of our hemisphere to call for an end to the U.S. embargo.

At home, they will celebrate social achievements such as the public health-care and education systems. But even Cuban officials admit that while those services are free and universal, they are also frayed due to underinvestment.

Especially since Raul Castro became president last February, officials and the state-controlled media are admitting other shortcomings. Raul Castro complains that production is too low and salaries provide insufficient incentive for work. He describes a looming demographic crisis of low birth rates, a shrinking workforce and a growing elderly population.

In October 2006, the communist youth newspaper documented how state retail outlets routinely cheat consumers. The next month, it reported that official unemployment figures, "never a reflection of reality," dramatically understate actual joblessness. A columnist cited the fable "The Emperor's New Clothes" to criticize dull, unanimous debates in Cuba's legislature.

On the street, many Cubans like their free social services but wonder why they come at the expense of basic political and economic freedoms. They wonder when a new generation will move into top leadership jobs, and when a big reform agenda will be put in place to tackle the big economic problems that the government itself has identified.

Cuba, in other words, is at a turning point in its history. By any reading, it's ripe for American influence -- but influence is exactly the opposite of what America has in Cuba today.

President George W. Bush thought he could bring Cuba's government down through tightened sanctions, tough talk and support for dissidents living in Cuba. It hasn't worked -- and with every new economic partnership Cuba builds, U.S. sanctions become more and more a nuisance rather than a strategic weapon.

President-elect Barack Obama -- the 11th American president to deal with a socialist government in Havana -- promises to steer a different course. He will "immediately allow unlimited family travel and remittances to the island" for Cuban Americans, and he promises to "pursue direct diplomacy" with Cuba, but without making specific the timing, conditions or agenda.

These are positive steps that can sustain Cuban families, generate cooperation between our governments and provide a forum to press human rights concerns.

But if President Obama stops there, he would be sticking with President Bush's fallacy that America can somehow have influence in Cuba while blocking broad contact between our societies. That is the opposite of American policy toward both China and the Soviet bloc during the Cold War. It makes no sense in the information age, especially not in a country like Cuba where Americans are welcomed and cultural and historical ties are deep.

The most consequential step the Obama administration could take would be to allow all Americans to travel freely to Cuba. Unrestricted travel would bring a surge in contacts, ideas and debate between American citizens and private institutions and their Cuban counterparts. The flow of information would increase, as would understanding, in both directions. A more prosperous Cuban economy would buy more U.S. farm exports. Latin America would welcome a sign of a new American diplomacy. And America would gain what it lacks now in Cuba: real influence.