THE ALLEGATIONS against Alan P. Gross, the U.S. Agency for International Development subcontractor now serving a 15-year prison sentence in Cuba, are absurd on their face. Mr. Gross’s so-called crime — furnishing a handful of poor Cuban Jews with equipment to connect to the Internet — is a garden-variety customs infraction; it hardly merits the trumped-up charge of undermining the regime in Havana.

But hopes for Mr. Gross’s release after almost two years in prison dwindled this month when Cuba’s highest court rejected his final appeal. Barring intervention by Raul Castro, Mr. Gross, a 62-year-old Potomac resident who is in poor health, will languish in prison indefinitely. And any chance for a thaw in U.S.-Cuban relations — a thaw that Cuba itself sought — will be shelved for the time being.

The extreme and unwarranted punishment meted out to Mr. Gross underscores how little really has changed in Havana since power passed from Fidel Castro to his brother. An initial flurry of reforms — or more accurately, talk about reforms — produced few substantive new freedoms for ordinary Cubans, though many have lost their state jobs. And the government — untested in free and open elections and still intent on sealing off the country from influences beyond Cuban shores — remains fragile and jittery, manifestly afraid of allowing its subjects to interact with the outside world.

The problem for the Castro regime is that without a surge in foreign investment — specifically, American investment — Cuba’s moribund economy will continue to wallow in a trough of its own making. And yet the government knows that an economic opening, no less than a political opening, could sow the seeds of its own demise by admitting new people, ideas and influences of the sort that tend to erode authoritarian systems and rules.

It is unclear exactly why Havana has chosen to make an example of Mr. Gross, whose efforts to distribute computers and satellite phones to a tiny minority community were ham-handed but hardly threatening, on their own, to the regime. Perhaps Raul Castro wanted a hostage to exchange for Cuban agents serving time for espionage in the United States. Or maybe Mr. Gross’s arrest and sentence are a display of pique at USAID’s ongoing democracy-
promotion program in Cuba, whose more or less explicit purpose is to hasten a transition to a freely elected and legitimate government.

Either way, the effect is to freeze whatever modest improvements in relations might have been contemplated in Washington or Havana, including further relaxation in travel, money transfers and communications. And since Cuba needs the United States far more than the United States needs Cuba, Havana, by reverting to its old hard-line instincts, has only shot itself in the foot.

Ultimately, the blame for the sorry episode lies with the Cuban government, whose hermetic fear of freedom is morally indefensible. Yet the Obama administration can also be faulted for allowing Cuba policy to drift and for failing to monitor USAID programs whose execution, as Mr. Gross’s case illustrated, has been artless. At this point, the administration must make clear that no progress in relations will be made until Mr. Gross — a development worker, not a spy — is released unconditionally.