They should bus ISIS out in to the desert. Then shoot the f’ers...
Anyone who embraced, or espouses the ISIS (Wahabbist) ideology, should be put down... period.
There was a time Humanity recognized the innate evil within itself, and refused to let it fester.... sadly these days, it is allowed to escape and fester to arise another day.
The Kurds (SDF) have been great about killing ISIS on the battlefield. Once ISIS surrenders or are captured though, the Kurds have no death penalty.
In Iraq, the Shi’ite Popular Mobilization Units (PMU, or Hash’d al Sahaabi) were notorious for executing captured ISIS with relish in many creative ways, and posting the videos on the Internet. Iraqis are still chasing down and killing former ISIS who are operating as guerrillas, law enforcement and Intelligence Services continue to search for War criminals who have tried to re-integrate, and death squads secretly pursue some who are not legally chargeable, for personal or tribal revenge.
Soon the Syrian Kurdish coalition SDF will be administering rather than engaging in combat, and we will probably see a similar dynamic there, as ISIS reforms into small guerrilla/terrorist cells rather than occupying territory. They have already started with a few IEDs and suicide bombers in Kurdish areas.
Kurdish internal security forces are some of the very best in the region, but they will be more challenged in the predominately Arab areas, which were the heartland of ISIS support and recruitment, whose tribes enthusiastically supported ISIS.