“agent provocateur (fr) A person placed in the ranks of the enemy during social, political, or industrial conflicts, to damage or compromise the enemy, provoking actions that might not otherwise have taken place. Agents provocateurs have been employed to provoke armed clashes between police and strikers or to induce strikers to act illegally. They have also been used by government agencies against revolutionary groups and in international politics to create disorder or ‘incidents’ as an excuse for war or intervention in others’ affairs.”
Excerpted from: Cook, Chris. Dictionary of Historical Terms. New York: Gramercy, 1998.