Beyond the three 'isms': Rethinking IR and the post-cold war order

The division of IR theory into the 'holy trinity' of the three 'isms' (realism, liberalism and constructivism) is the most common classification of theories in the field. While this division has numerous theoretical benefits, it also has some major shortcomings with regard to the conceptualization of substantive changes in world politics, especially in the post-Cold War security order. In order to better capture conceptually these changes and also to be able to provide falsifiable predictions, we offer a novel conceptual classification based on three key factors: (i) the level of analysis used by the approach; (ii) whether the state continues to be the central actor in the international system and (iii) whether the post-Cold War international system is more peaceful in relation to previous eras. Each of the approaches identified in this work - 'Liberal/Constructivist Optimists', 'Hegemonic Optimists', 'New Conflict Pessimists' and 'Balance of Power Pessimists' - highlights different and sometimes contradictory aspects of these developments. We probe the empirical applicability of this novel typology on a sequential time base since the end of the Cold War and find that each of these approaches accounts for the major patterns of the international security order in a given time period but not in other periods. We also briefly identify the conditions under which each one perspective is more valid than the others for accounting for key patterns of international security.