A lot of people who strongly believe in the war on terror are not above sowing a little terror of their own. From the reaction to last week's Supreme Court decision on Guantanamo, you would think the detainees were all going to be trained, armed and set free at Ground Zero, with free shuttle service to the nearest airport.

John McCain denounced the ruling, which said inmates may ask for federal court review under a procedure known as habeas corpus, as "one of the worst decisions in the history of this country." Former Bush Justice Department official John Yoo warned that henceforth, captured enemy fighters will be read their Miranda rights. The irrepressible Wall Street Journal had a cartoon with a judge atop a cage labeled "Gitmo" watching masked inmates stream out wearing suicide vests and lugging AK-47s.

All this outrage builds on the dissent registered by Justice Antonin Scalia. The court's decision "will make the war harder on us," he thundered. "It will almost certainly cause more Americans to be killed."

Well, it won't have that effect unless it leads to inmates being released -- which it has not, will not anytime soon, and may not ever. If and when it does, he may have a point, though not necessarily a powerful one.

Anytime you let someone out of prison, even if he's innocent, you create the possibility that he will someday kill someone. Scalia makes much of the supposed fact that 30 of the detainees freed from Guantanamo "have returned to the battlefield." Just because they were later captured or killed, however, doesn't mean they "returned" to the war.

Some of them may have been victims of mistaken identity, which could explain why those softhearted folks at the Pentagon let them go. But stick a blameless unfortunate in a cage for six years, abusing him in the process, and when he comes out, he may seek revenge. The only way to eliminate the risk is to keep all the detainees locked up forever.

Even the Bush administration has not gone that far. It was happy to free more than 500 inmates over the years. When it did, by the way, nobody accused the president of causing more Americans to be killed.

Besides, any releases are only speculative right now. To have a chance at freedom, a prisoner will have to make a plausible case that he's innocent. The administration had already planned to try 80 of the detainees before military commissions, which suggests it has abundant evidence of guilt.

Presumably the Defense Department has information to show that many, if not all, of the others were connected to al-Qaida or other enemy forces. If the government presents incriminating evidence that the inmate can't refute, a habeas corpus petition will be about as useful to him as a snowboard.

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.