Terrorism is , in the broadest sense , the use of intentionally indiscriminate violence as a means to create terror among masses of people ; or fear to achieve a religious or political aim . It is used in this regard primarily to refer to violence during peacetime or in context of war against non-combatants ( mostly civilians and neutral military personnel ) . The terms " terrorist " and " terrorism " originated during the French Revolution of the late 18th century but gained mainstream popularity in the 1970s in news reports and books covering the conflicts in Northern Ireland , the Basque Country and Palestine . The increased use of suicide attacks from the 1980s onwards was typified by the September 11 attacks in New York City and Washington , D.C. in 2001
September 11 attacks
September 11 attacks
Terrorism