The war isn't over, whether they are 'enemy combatants' or 'non-enemy combatants' as defined in Geneva Conventions, it's pretty much assumed they will be detained until the end of hostilities. Then it would be decided whether to put on trial or just release.
And who is our war against? Terrorism is a tactic and an ideology.
Do you keep them interned until they're dead because a war against a tactic can't ever end since the tactic will always be used.
You're mixing apples and oranges.