EU military operation ALTHEA represents, no doubt, an European Union's global contribution to the crisis management. In fact, the development of a civic-military capacity, in the framework of the European Strategy of Security, constitutes an effective mechanism for international peace and security. So, EU, requiring recourse to NATO assets and capabilities, is been able to send an operation of these characteristics in the Balkan region, ensuring its political engagement to these questions. In addition, the evolution of this operation in relation to European Union's Petersberg tasks is significant in third States participation, and all the States will have the same rights and obligations as the EU participanting Member States; financing the mission, through the permanent mechanism called ATHENA; and, finally, coordinating different interpillar instruments. All that demonstrates an important implementation of European Security Strategy, as well as an EU's greater presence in international framework and in the field of maintain peace and security.