This book addresses the links between war, state and sovereignty using an interdisciplinary approach. The authors and editors investigate the transformation of the state through the practices of security governance - an effective way to question the evolution of authority and legitimacy of state violence, and the organisation of human societies. This work contributes to the understanding of the transformation of state through the prism of security challenges and provides the means to identify the evolution of their regalian contours, the legal and technical forms of regulating violence, and the legitimisation of public power. This volume shows that the contribution of the social sciences is decisive for understanding the changes of the role and insertion of armed forces in their political, social and professional environment.