The point of terrorism is to upset and make people feel vulnerable. ‘The trouble with terrorism’ attempts to define terrorism by examining the relationship between terror and war. Should all acts of terrorism be regarded as illegal? What factors decide whether an act of violence by non-state actors is justifiable despite being illegal? There are three elements in the terror process: seizing attention (shock, horror, fear, or revulsion), getting the terrorist message across, and fight or flight (the response to terrorism). The different strategies of terror, the shapes and forms of different terrorist organizations and their arms, as well as the role of women in terrorism are also considered.