With the ever farther advancement of globalization, governance has become one of the most prominent theoretical concepts to describe today's world. Governance theory is concerned with a system of rule through non-hierarchical governing modes, such as networks and market mechanisms. Initially the field of security was ignored, as it was seen as the last bastion of the nation state. When the concept of security governance emerged at the beginning of the millennium, it sought to take account of transnational threats, such as nuclear proliferation or cluster bombs. However, the traditional security domain of the state, i.e. the provision of security by military force, is still exempt from governance theory. Provoked by the increasing support of private actors to military operations, Gloria Westermeyer aims to investigate whether this exemption is still valid. Based on the conduct of Intelligence, Surveillance and Reconnaissance services in the German ISAF Mission, the author examines the impact of private actors on the governance of today's military affairs. What is the relative power of private security actors vis-à-vis the state? Which factors determine if, to what extent and why private actors support the military? Under what circumstances and how may security functions be privatized without undermining the state's interest?