This article argues that, thanks to the progress of hemispheric multilateralism since the end of the Cold War, the conditions for identifying a nascent security community have been fulfilled in the Americas. The evolution has not been perfectly linear, and in light of the tensions that have marked inter-American relations during the past few years, it remains an open question whether the renewal of security cooperation can be pursued in the future. Yet it seems clear that, with regard to interstate conflicts, the Americas currently make up a more peaceful region than at any other time in modern history. The body of our article relates this unprecedented situation to the recent developments of inter-American diplomacy in the field of security. The first part focuses on the 1990s and shows how the notion of cooperative security has served as intellectual glue and helped stimulate a transformation of inter-American politics. The second part explains how the emergence of the notion of multidimensional security during the 2000s made it possible to further institutionalize hemispheric cooperation.