Was Cuba ever really a threat to the United States?

On New Year's Day 1959, Fidel Castro's ragtag guerrilla army marched triumphantly into Havana. Mr. Castro himself followed a few days later and began his half-century of work carrying out his revolution. This turned out to be a real revolution as distinguished from the coups d'etat that had previously characterized Cuban politics. By the time Castro turned over power to his younger brother Raúl in July 2006, he had ruled longer than any other current world leader.

We know that Castro is sick; we do not know his diagnosis.

The US intelligence community thinks he has terminal cancer. A Spanish doctor who recently examined him says he does not have cancer and can return to work after rehabilitation. Either way, it is likely that his era has ended.

Castro has outlasted nine US presidents: Eisenhower, Kennedy, Johnson, Nixon, Ford, Carter, Reagan, George H.W. Bush, and Clinton. A tenth president, George W. Bush, is halfway through his second term. All of these except Mr. Carter did everything they and their CIA directors could think of to bring Castro down – without success. (Carter took a step toward restoring diplomatic relations but did not follow through after Cuba intervened in the Angolan civil war.)

The United States would long since have come to terms with any other revolutionary Latin American government. That it has not done so with Cuba is due mainly to ideological bias in Washington and Havana as well as the baleful influence of hordes of anti-Castro refugees in Miami.

Castro has an efficient and ubiquitous secret police and has not hesitated to use it to quash opposition. But also, and somewhat paradoxically, he has had remarkable public support. In major part, this came from what he did to change Cuban society.

He improved healthcare and made it more widely available, despite a drain of skilled health professionals who streamed out of Cuba into Miami. He improved literacy – which was already good by Latin American standards – by forming "literacy brigades" to teach illiterate men and women how to read. Schoolchildren are clean and neatly dressed. They even wear shoes. They look well fed – no distended bellies, no spindly arms and legs.

The Mafia was thrown out of Cuba when Castro took power, and with it, the legality of gambling and prostitution.

The Castro regime attacked the housing shortage by obtaining land and building materials and organizing teams of workers who built apartment houses. Construction workers then had priority for living in the apartments.

The revolution got a big boost from the Soviet Union, which sold oil for less than the world price and bought sugar for more than the world price. This provided a subsidy of $3 billion to $4 billion a year, which ended with the collapse of the Soviet Union.

This precipitated a major economic crisis for Cuba. Castro reacted by reluctantly allowing hard currency investment in tourist facilities. Europeans flocked to them, and Cuba became in effect a two-currency economy. On one side was the Cuban peso; on the other was the US dollar which, despite opposition from both the Cuban government and the US Treasury, was what the melange of largely European currencies settled into.

On one side are Cubans who are living reasonably well; on the other are Cubans who are barely surviving.

There the matter rests. It remains to be seen who the long-term successor to Fidel Castro will be, or what he or she will do, but the US can learn some things from its Cuban experience. Apart from the missile crisis (which was precipitated by the Soviet Union), Cuba has never been a threat to the United States. Rather, as Sen. J. William Fulbright (D) said in arguing with President Kennedy against the 1961 Bay of Pigs invasion, Cuba has been "a thorn in the flesh, not a dagger in the heart." Why, then, have so many presidents, some of them otherwise sensible, been so upset about it? In part, Florida politics; in part, the possible spread of communism; in part the fear that Castro might seek to extend his revolutionelsewhere in the Western Hemisphere.

Yet Castro said many times that revolutions cannot be exported. He warned President Salvador Allende, who died trying to bring a similar revolution to Chile, not to pick a fight with the US. His assertions don't match with the US fear that Castro would try to spread his revolution.

A regime change is under way in Cuba. Maybe we would all be better off if there were a policy change in the US as well.

• Pat M. Holt is former chief of staff of the Senate Foreign Relations Committee.