Through advanced didactics such as seminars, class discussions and presentations of individual research project, this course aims to provide students with the analytical tools necessary for a critical understanding of the evolution of the international system since the late Eighties, especially through of the evolution of the concept of international security. Therefore, particular attention will be given to conflict management and international crises, as well as to the emergence of new forms of threat and finally, the difficulties encountered by national states and international and supranational organizations in forging widespread consensus around the instruments with which to intervene in time of crisis to preserve security and stability.