Terrorism is the exercise of unconventional violence to achieve political objectives. What fits this simple definition is a matter of considerable dispute. Often, those in positions of political power characterize as terrorism those challenges to their established political authority that—rather than employing conventional means to political change, from peaceful discourse to declared warfare—employ violent, frequently surprise, attacks, in some cases on innocent civilian targets. Those who incite, endorse, or commit such attacks may defend them on ideological or religious grounds as the most expedient way to make a statement and effect change against a more politically, economically, or militarily powerful adversary. They may contend that the real terrorists are those in political power who engage in overt or covert military action and political maneuvering to ...