President Obama has promised to shut down the detention camp at Guantanamo Bay, seeking to erase a blot on America's global image. He has also reached out to Cuba, easing some travel and financial restrictions in an effort to recast Washington's approach to the island. These two initiatives have proceeded on separate tracks so far, but now is the time to bring them together. Hiding in plain sight, the U.S. naval base at Guantanamo Bay is the ideal place for Obama to launch a far-reaching transformation of Washington's relationship with its communist neighbor.

How? By preparing to give Guantanamo back to Cuba.

It's not as impossible as it sounds. The United States has scaled back, modified or even withdrawn its military presence elsewhere; think Okinawa, South Korea, Subic Bay in the Philippines or Vieques in Puerto Rico. Whatever Guantanamo's minor strategic value to the United States for processing refugees or as a counter-narcotics outpost, the costs of staying permanently — with the stain of the prisons, the base's imperial legacy and the animosity of the host government — outweigh the benefits.

The time to begin this transition is now. By transforming Guantanamo as part of a broader remaking of Washington's relationship with Cuba, the Obama administration can begin fixing what the president himself has decried as a "failed" policy. It can upend a U.S.-Cuban stalemate that has barely budged for 50 years and can put to the test Raul Castro's stated willingness to entertain meaningful changes.

I visited the 45-square-mile U.S. naval base at the southeastern tip of Cuba last month, at the invitation of Adm. James Stavridis, head of U.S. Southern Command. I went less to see the prison cells or learn about detainee treatment (though I did both) than to explore a region that I'd never visited in a quarter-century of traveling to and writing about the island. I wanted to imagine how the base could evolve once the detention facility is shut down and the eyes of the world shift elsewhere.

Since the Bay of Pigs invasion more than four decades ago, Havana has demanded the return of the base territory, but Washington has found little incentive to leave. The base is a financial freebie; the annual rent is only $4,000, although on grounds of pride and principle, Cuba has not cashed the check since 1959.

Yet the Cuban government has never taken steps, military or otherwise, to get the base back. "We are audacious and valiant," remarked Cuban President Osvaldo Dorticos in 1964, "but we are not stupid." Echoing such practicality, Raul Castro has referred to Guantanamo as a "neutral place" where dialogue with the Obama administration might one day unfold.

Despite the glimmers of political will on both sides, a rapprochement between Washington and Havana will take time. Obama has called for the release of Cuba's political prisoners. Cuba has its eye on the dismantling of American commercial sanctions and the return of Cuban spies now serving lengthy sentences in U.S. jails. The Castro brothers are unlikely to frame any reforms as a concession to Washington, while the Obama administration will wait to see how the government of Raul Castro fulfills its commitment to "improve the material and spiritual lives of the Cuban people."

Of course, just as Obama is not going to lift the embargo tomorrow, neither will he simply give back the base the next day. But short of anything so bold, the two governments and their armed forces have already shown that Guantanamo can eventually become an ideology-free zone.

Julia E. Sweig, a senior fellow at the Council on Foreign Relations, is the author of "Inside the Cuban Revolution" and the forthcoming "Cuba: What Everyone Needs to Know." CFR research associate Michael Bustamante contributed to this article. This commentary was written for The Washington Post.