Constructivism entails a wide range of theoretical perspectives whose common denominators include “an emphasis on the importance of normative as well as material structures, on the role of identity in shaping political action and on the mutually constitutive relationship between agents and structures” (Reus-Smith, 2005: 188). While all constructivist approaches agree on the definition of structure and the role of identity in international politics, they mainly diverge on epistemology and methodology on the one hand and the levels of analysis on the other. In terms of epistemology and methodology, constructivism can be divided into three main categories: neoclassical, postmodern and naturalistic constructivism.