SpookyFrank
A cheap source of teeth for aquarium gravel
What about people who (eventually) purport to have changed their mind only after they've been captured, and are detained in circumstances where they have an overwhelming motive to say whatever it takes (whether or not it's true), and where the genuineness of their supposed conversion can't really be tested?
Perhaps they could face some sort of due process? And perhaps that should happen in their country of birth and the country that failed to adequately safeguard them in the first place, as that would seem to fit with the notion of 'taking responsibility' on which the concept of retributive justice is predicated.