Nor are the courts likely to let the American Civil Liberties Union draw up the standards for release. Justice Anthony Kennedy, writing the majority opinion, indicated the judiciary will err on the side of caution.

"Habeas corpus proceedings need not resemble a criminal trial," he stipulated, for those worried about Miranda warnings. Though inmates have rights, he noted, "it does not follow that a habeas corpus court may disregard the dangers the detention in these cases was intended to prevent."

Let's suppose there's an inmate whom the Pentagon thinks was fighting for al-Qaida but lacks any supporting evidence it can use in court. Does he now have a get-out-of-Gitmo-free card? Not necessarily.

In that case, says Northwestern University law professor Ronald Allen, the government could classify him as a prisoner of war -- who, like POWs in previous wars, may be held until the hostilities cease. The trouble, from the administration's point of view, is that he would then be entitled to standard POW protections, such as being treated humanely and not being punished for refusing to answer questions. But at this point, that's a small price to pay.

It's also a small price to say that if the executive wants to capture someone, treat him as an unlawful enemy combatant and hold him for the rest of his life, it should have to justify that decision to someone other than itself. Critics of this decision are terrified that the courts will have the power to free innocent men. But really, the alternative is a lot scarier.