If the US is at war, then they should be held under the terms of the Geneva convention. If not, they should be held as civilians with the right to due process accorded to them.
Or possibly Walter Mitty.
Besides, you've just admitted that a driver's license *is* an ID card- an identity document required to participate in a civic duty. Next!
There is no war game, simulation or RPG mechanic so utterly baroque that someone won't decry streamlining it as 'dumbing down' the game.
That's a keeper!
We can defeat gravity. The problem is the paperwork involved.