TWO LEADERS of Cuba’s Jewish community have visited American Alan Gross at the maximum-security military hospital in Havana where he has been confined since Dec. 3, 2009. They lighted Hanukkah candles with him, emerging later to pronounce him healthy and hopeful. But for Mr. Gross’s family in Bethesda, this report was cold comfort. Gaunt and depressed, the 62-year-old was not among nearly 3,000 prisoners granted amnesty by President Raul Castro on Dec. 23; though an ailing mother and daughter await back home, Mr. Gross remains under a 15-year sentence for “acts to undermine the integrity and independence” of Cuba.

Cuba’s accusations stem from Mr. Gross’s humanitarian work, on behalf of a company that operates with U.S. democracy-promotion funds, to support his fellow Jews on the island. Specifically, he helped them establish an intranet and improve their access to the Internet.

Much has been made of the fact that Mr. Gross brought computer and cellphone equipment with him when he came to the island, but on at least one occasion, Cuban authorities searched his bags and let him bring the equipment into the country after paying a tax. “I did nothing in Cuba that is not done on a daily basis in millions of homes and offices around the world,” Mr. Gross told the court that found him guilty last March. Alas, that’s just the point: In Cuba, helping people communicate freely can be a crime.

The Castro government sees Mr. Gross as a potential bargaining chip in its campaign to win the return of five Cuban spies from the United States. This effort has unfortunately received support from Hollywood celebrities, Nobelists and even, after a fashion, former president Jimmy Carter, who called for the spies’ release when he visited Havana in March (while saying their fate should be “separate” from that of Mr. Gross).

There is no equivalence, moral or otherwise, between the illegal espionage of the Cubans and the conduct of Mr. Gross. The five Cubans were sentenced to long prison terms in 2001 for, among other things, operating as undeclared foreign agents and infiltrating U.S. military installations in South Florida. All are acknowledged intelligence officers, unlike Mr. Gross, a would-be humanitarian who got himself caught up in the U.S.-Cuban dispute over U.S. efforts to promote civil society on the island.

Yet Cuban officials now link the cases. Referring to the five intelligence agents, the president of Cuba’s parliament, Ricardo Alarcon, has cynically called on “the Jewish community in the U.S.” to “persuade American politicians that it’s time to put an end to this injustice and, in the process, find other humanitarian solutions.”

Though the Obama administration is working diplomatic channels for Mr. Gross’s release, it has wisely refused to entertain swapping the Cuban spies for him. At most, once Mr. Gross is free, the administration might consider asking the federal court in Florida to permit the exit to Cuba of the one convicted spy who has finished his prison time. A dual U.S.-Cuban citizen, he is now serving three years of parole.

But former New Mexico governor Bill Richardson floated that idea during his visit to Havana in October, and the Cubans turned him down flat. Such are the vagaries of the Communist state, whose long list of victims has tragically grown to include Alan Gross. The U.S. government should keep trying to bring him home — without yielding to Cuban extortion.