I am going to consider the UN Foreign (Terrorist) Fighter FTF regime from a different perspective, by exploring how the regime interacts with both the international law relating to terrorism and international criminal law. I will to do this by looking first at the definition of terrorism and then at how the UK Supreme Court approached the issue of terrorism and armed conflict. In addition, I am going to apply a little prosecutorial pragmatism to these difficult legal issues, and suggest that we focus on the crime.