The private provision of security and military services challenges conventional assumptions about the roles of the nation state as the main protagonist in military affairs and as the guarantor of physical security for its citizens. In the absence of effective legal or regulatory structures, such activities raise issues of legality, legitimacy and accountability in the sphere of security policy. This study assesses "the impact of" the privatization of security in various security contexts and examines some of the ways in which the international community might respond to this development.