Since 1959, fortunes have been lost betting on the end of the Cuban revolution. Countless books, essays, articles, statements, and resolutions have predicted the fall of Fidel Castro. These false warnings have been a source of endless frustration for those hoping for radical change in Cuba. Despite this record, it's time to raise the question again. Is the Castro regime entering its final days?

Three factors suggest Cuba is at a critical turning point. First, the economy is in its most severe crisis since the Soviet Union collapsed and stopped subsidizing Cuba in the early 1990s. Last year's fall in the price of nickel (Cuba's largest export) and in tourism, the stagnation of remittances from relatives in Miami, and recent hurricanes have paralyzed the island. Blackouts, terrible deficiencies in health care, food shortages, a housing crisis, and Cuba's suspension of debt payments to its creditors since January 2009 all point to a bleak future. Cuba now relies heavily on subsidies from Venezuela, but they're not enough. Cubans are accustomed to suffering, but their misery is reaching new lows. And it's no longer so easy to blame American imperialism. Barack Obama seems to be hugely popular with ordinary Cubans.

That explains factor No. 2: new signs of public protest. A hunger-strike movement is gathering steam after the death of political prisoner Orlando Zapata, a 42-year-old activist who refused food for more than 80 days. Zapata's death dashed any chance of improving relations with the European Union, the United States—which condemned his death and called for the release of all political prisoners—and Mexico, which didn't, and whose president had planned to travel to Havana and no longer has the leeway to do so. And it inspired another dissident, Guillermo Fariñas, to launch his own hunger strike, seeking the release of other imprisoned activists. Fariñas has a rare eloquence and altruism, which are winning him a stature few dissidents have ever achieved. If his health starts to fail, events could take an unforeseeable turn.