The author examines historical and contemporary examples of military involvement in counterterrorism, outlining the specific roles which the armed forces of liberal democracies have performed in combating terrorism, both in a domestic and international context. He describes the political, strategic, conceptual, diplomatic, and ethical problems that can arise when a state’s armed forces become engaged in counterterrorism, and argues that military power can only be employed as part of a coordinated counterterrorist strategy aimed at the containment and frustration-rather than the physical elimination-of the terrorist group(s) concerned.