Chapter 20 Defense in a Globalized World: An Introduction Since the end of the Cold War the world remains a dangerous place with new threats: regional conflicts transnational terrorist networks rogue states and weapons of mass destruction (i.e. chemical biological radiological and nuclear). The second volume of the Handbook of Defense Economics addresses defense needs practices threats agents and policies in the modern era of globalization. This new era involves novel technologies new business practices and enhanced cross border flows. Such ever growing flows mean that military armaments and armies are less equipped to keep out unwanted intruders. This introductory chapter sets the stage for this volume in three ways. First the chapter identifies how threats have changed since the Cold War. For example the end of the superpower arms race has brought forth new issues such as the quelling of local conflicts the role of economic sanctions and the challenge of asymmetric warfare. There are also new concerns about military manpower and the role of reservists and civilian contractors during a time when most countries have downsized their forces. Second the chapter indicates the choice of topics and how these topics differ from those in Volume 1. In particular we selected chapters on topics not covered in Volume 1 (e.g. civil wars peacekeeping trade and peace and economic sanctions); chapters on past topics where there has been significant advances in knowledge (e.g. conflict terrorism arms races and military manpower); and chapters on topics that reflects the influence of globalization and new threats (e.g. terrorism trade and peace and arms industries). Third the chapter provides a brief overview of each chapter in the volume.