Explosives carried in the rucksack. A bomb under a park bench. A hi-jacked aeroplane. Today these images of terrorismour broadcast into our homes.However, terrorism itself embodies far more than this. Those who create terror are not just organisations such as Al Quaeda or ETA but also states and repressive governing regimes. In examining case studies of religious, political and separatist terrorist groups Terrorism finds that terrorists are not 'another person's freedom fighters'. Terrorist groups are also different from state and regime terrorists. They are the instigators of revolutionary reigns of terror; totalitarian regimes; genocidal state terrorist campaigns; death squads and international state terrorism. Explanations are explored for each form of terrorism, sometimes causes are found, sometimes reasons are more important. No matter the form, however, terrorism remains essentially the same - a system of summary justice: of its essence the deliberate targeting of innocents as victims.