The author establishes that the central feature of terrorism is political violence. He claims that there are two forms of terrorism, that used by politically-charged groups against their governments, and that used by governments or their agents such as Hitler’s extermination camps. Distinctions in state terrorism can be made on the basis of legality, scale and degree. The chapter also reviews the psychology of state terrorism, showing that psychological roots are widespread and deep. Finally, responses to state and other forms of terrorism conclude.