IN A KIND OF apotheosis of multiculturalism, the choicest al Qaeda suspects captured in the war on terrorism are about to take up residence under the American flag, at Guantanamo Bay, the U.S. Navy base at the eastern tip of Cuba that has incongruously stayed in operation throughout the four decades of Castro’s Communist rule. There, side by side–though separated by prison walls and the base perimeter–will coexist young men whose heads are filled respectively with the intoxication of jihad plus the trauma of defeat; newly burnished American patriotism; and whatever propaganda Castro’s impoverished police state reserves for its trusted Frontier Brigade, which mans the only Cold War border in the hemisphere.

It’s a border still to this day fortified against defectors with Soviet-style minefields, sirens, and searchlights. Almost every night there’s an incident of some kind at the border, says Patrick Moore, an assistant professor of history at the University of West Florida who visited Guantanamo in August and is researching its history. “Sometimes it’s just a rabbit hitting a mine,” he says. “But the Frontier Brigade is pretty effective. They stop 95 percent of would-be defectors.”