terrorism, the calculated use of violence to create a general climate of fear in a population and thereby to bring about a particular political objective. Terrorism has been practiced by political organizations with both rightist and leftist objectives, by nationalistic and religious groups, by revolutionaries, and even by state institutions such as armies, intelligence services, and police.
Definitions of terrorism are usually complex and controversial, and, because of the inherent ferocity and violence of terrorism, the term in its popular usage has developed an intense stigma. It was first coined in the 1790s to refer to the terror used during the French Revolution by the revolutionaries against their opponents.