Chapter 21 Economics of Defense in a Globalized World In a world continuously beset by conflict and violence the positive study of international security and defense has developed rapidly over the past decade as a cohesive discipline within economics. Part of the cause for this trend is the revolutionary effects of globalization and its new challenges to world security and stability. The challenges to security now come from new sources; they threaten new dangers and require new instruments and concepts from us. The field of play for defense economics has thus greatly increased but the opportunity to exploit new insights from throughout economics grown accordingly. This essay aspires to show how the recent developments in models of international political economy relate to study of this phenomenal evolution of the worlds strategic situation and challenges to its safety. Here I give one perspective on the contributions expected of defense economics in a globalized world where old patterns of thinking risk obsolescence. Emphasis is focused on (a) how the field is changing and the relation between new security challenges and required new analytic approaches (b) how developing ideas about conflict predation and governance have entered into and greatly influenced defense economics and (c) how this raises questions over what should be retained from study of earlier eras and what discarded.