When is a War Not a War?
In his view, some of the prisoners would be charged with crimes and tried, some would be returned to the governments whose citizens they were.
And some would be held until the war was over.
Which raises an obvious question: What does it mean for the War on Terror to be over? There is no enemy government to surrender. There is not even an enemy organization to surrender. While Al Quaeda has played a central role, we would not consider the war to be over if it shut down and was replaced by other terrorist organizations.
The problem is that the "War on Terror" is at least in part a metaphor. It is in some ways more like the War on Drugs or the War on Poverty, a project given emotional force by analogizing it to a military conflict, than it is like WW II or the Korean War.
Suppose the President declared a War on Crime--as, for all I know, some President at some point has. Is he then entitled to arrest people he claims are criminals and hold them without trial for an indefinite period of time--as prisoners of war?
The analogy is not perfect. The attack on the World Trade Center was more like an act of war than it was like a bank robbery. But it was less like an act of war than the Pearl Harbor attack was, not only because the targets were not primarily military but because the attackers were not agents of a hostile state. The War on Terror is not as metaphorical as the War on Drugs. But it fits the pattern of war as usually and literally understood poorly enough to make a policy of taking people prisoners and holding them without trial until the war is over at best problematical.