Since 2012, nearly 5000 Europeans have left for Syria and Iraq, many to fight alongside jihadist forces. Some of them have already returned, while quite a few – some 2500 according to certain estimates – still remain in place, but could return in the foreseeable future. Who are these ‘returnees’? How are they monitored when they come back? How do they reintegrate? Do they pose a threat? These sensitive and difficult questions will be at the heart of this lecture’s discussions.