They end up in a desert proclaiming their innocence and they like the victims suffer the actions of the terrorists. Mohamed Lahouaiej-Bouhlel's wife and children would be removed from the western world never to return. In the long run we would be slowly removing the Islamic threat of Terrorism to the west. Minds would be focused on the repercussions of terrorism, minds would be focused on stopping it happening.
At the moment we can continue to carry on as normal but in the end there will be a backlash and government will be powerless to act. Rounded up and sent packing on mass or act now and get rid of the nutters?