This article addresses, from a sociological point of view, the involvement of the Portuguese armed forces in international peace operations. After reviewing some major sociological contributions for understanding change in military institutions and the development of international military missions, it concentrates on the Portuguese case, aiming at uncovering the place and meaning of peace operations for the Portuguese armed forces during the past two decades. After briefly recalling some facts and figures concerning the Portuguese participation in peace operations, it addresses the relevance of such involvement at different analytical levels, showing that peace operations have come to play a decisive role in the national defence political discourse, the organizational configuration of the Portuguese armed forces and the soldiers' professional identity. The last section consists of a short prospective exercise looking at possible implications of disengagement from international peace missions. The conclusion is that, considering the strategic, organizational and sociopsychological centrality of these missions, disengagement is likely to have important consequences in the overall strategic definition, purpose and identity of the