These non-traditional combatants were at war against the US and others without benefit of country or uniform. It seems to me they could have been legally executed on the field of battle. They should be grateful for the humanities they have been accorded.
However, these left-wing screwballs continue to act as if we just pick Achmed up off the street because we don't like his name, or whatever, and throw him into a gulag. Idiots!
As soon as they're back on the street, they're back to their old habits.
Execution always works.