 The history of terrorism is probably coextensive with the history of political violence. The term “terrorism”, however, is relatively recent: it has been in use since late 18th century. Its use has repeatedly shifted in some significant respects. Moreover, in contemporary political discourse the word is often employed as a polemical term whose strong emotional charge occludes its somewhat vague descriptive meaning. All this tends to get in the way of sustained rational discussion of the nature and moral standing of terrorism and the best ways of coping with it.