Foreign Terrorist Fighters undermine international peace and security by joining terrorist organisations and by contributing to the conflict and to the execution of terrorist acts, both in the conflict theatres and their home countries. Policies to counteract this phenomenon have been adopted at both the international and national levels, including security, administrative and preventative measures. This policy brief will focus on the legal measures, specifically the prosecutorial
approach, and the difficulties that prosecutions of those who have travelled to the destination countries where the conflict takes place bring along. Given those difficulties, the main question this policy brief seeks to answer is whether there is a role for the military to play in assisting prosecutors in collecting evidence and arresting suspects in countries of destination in order to try them in a criminal court under a civilian jurisdiction. After elaborating on several future scenarios in Syria and Iraq, the policy brief concludes by giving recommendations for cooperation between the military and civilian prosecutors.