The dissertation deals with the constructivist theory of Alexander Wendt and the theoretical debate about the Cold War, particularly its end, highlighting the social aspect of the international system, and the many shapes this structure of shared knowledge can take: the cultures of anarchy. Analyzing the New Thinking as a critical and reflexive action, and using the tools of symbolic interaction,Wendts idealist and structural theory opens up to the state actors agency, and shows how identities and interests are continually sustained or altered in the process of interaction.