ABSTRACT
The peace operations belong to the contemporary international system, but not to the international system of the past. The background of such an innovation is the turn of post-Second World War international relations towards multilateralism. It was brought about by the United Nations 60 years ago and has greatly developed since then. This chapter firstly examines multilateral security and peace operations within the United Nations framework and, then, investigates the features and issues that have occupied the multilateral security stage. The second section deals with the spectacular growth in the number and multiplication of the tasks in peace operations after 1989. The third section deals with the issues that this instrument triggers in the public debate on multilateral security, namely the legitimacy, efficacy, and function issue. The last two sections delve into the varying forms of the agency in multilateral security to understand why some States are more ready than the others to cover the costs of peace operations and how the variety of agency affects the practice of multilateral security.
