Popolo applies Foucauldian methodology to the understanding of Complexity Science for the purposes of generating new understandings related to International Relations in general and to the Kosovo conflict in particular. He provides an epistemic analysis to the history of International Relations theory to reveal its intrinsic 'modernity', highlighting how such modernity derives from a particular understanding of scientific epistemology, which is being radically undermined by the emergence of Complexity Science. Importantly, the book shows how these theoretical issues affect specific understandings of crisis - in this case Kosovo - leading to specific policy decisions in the real world of international policy-making.