Not all of them.
People are in there who were just picked up in the area. This is the point.
Also, there is no declaration of war. There is no nation named. Point to the place called "Terror" on the map. So theoretically, and up to this point, actually, those men could be held for the rest of their lives without proof that they did anything at all.
If someone picked up was actually shooting at someone, that's different.
We treat murderers better than this.