With last Wednesday’s announcement of plans to release 52 political prisoners who were arrested during a 2003 crackdown, Cuban President Raúl Castro took his first major step away from decades of hardline policy. Under the deal negotiated with Cardinal Jaime Ortega of the Roman Catholic Church, five of the prisoners were to be released “within days,” the church announced, and the rest within months, bringing the number of political prisoners in Cuba—once numbering in the tens of thousands—to fewer than 150, the lowest in the regime’s history. A half century of repression appears to be ending.

At first glance Castro, who took over from his ailing brother Fidel in 2006, might seem to have blinked in the face of a crisis. One of the regime’s most charismatic critics, a 48-year-old Santa Clara psychologist named Guillermo Fariñas, was four and a half months into a hunger strike, surviving on an intravenous lifeline. The Catholic Church stepped in to negotiate. On Thursday, with the deal all but sealed, Fariñas declared his protest suspended and took his first sips of water.

But Havana has already turned the concession to quick advantage. By taking the most obvious human-rights issue off the table, Raúl Castro has driven a new wedge between U.S. and European policies. Spanish Foreign Minister Miguel Ángel Moratinos, who helped broker the deal, crowed that European negotiation, not American confrontation, had triumphed. Besides, the prisoner release is more symbol than substance. Cuba continues to detain critics, often for short periods, with no formal charges. Harassment and censorship have proved adequate to control the populace. Despite growing discontent over corruption, public protest is almost unknown. The Castro regime may be broke, but it’s firmly in control.

Castro has made his move—and now it’s Washington’s turn. While Hillary Clinton called the prisoner deal “overdue but nonetheless very welcome,” the Obama administration should be careful what it wishes for. The stone-faced Raúl has put 52 cards on the table. If, after years of advocating tit-for-tat improvements, Washington does not reciprocate—perhaps by increasing trade with the island or finally appointing a U.S. ambassador to a post left vacant since 1961—the Obama administration could look like the unhappy gambler whose bluff was called.