Charles Krauthammer writes about the case of Yaser Hamdi, a Taliban soldier captured by the US military, who turns out to be a US citizen. He makes sense, but fails to grapple with the really tough question (which, admittedly, is not directly raised by the Hamdi case).

Hamdi was captured on the field of battle, armed, living and fighting among enemy soldiers. The military should therefore, says The Hammer, be able to hold him as a prisoner of war, with correspondingly limited rights. If they have the right to shoot him in combat, surely they can keep him prisoner. Fair enough.

But "we should acknowledge a different standard for a citizen apprehended unarmed in the United States" [emphasis added], with standard criminal procedures and standards, and the burden of proof being on the military to prove combatant status. Also fair enough.

But that leaves a yawning gap in between, one particularly relevant to the current conflict. What about those captured on home territory, but engaged in "asymmetric warfare", i.e., terrorism? Suppose, for example, that United Flight 93 had been brought home safely, and after the hijackers were detained, one of them was discovered to be a U.S. citizen. He would have committed what the government considers to be an act of war. What standard would apply?

I haven't thought of a good answer for this question. But we may have to come up with an answer, and soon; the issue may be forced upon us.