Why do states do what they do? Who are the relevant nonstate actors in international politics and why do they do what they do? What causes conflict and cooperation in the international system? These are some of the most basic questions that the discipline of International Relations (IR) seeks to answer; they are also the questions that drive the objectives, organization and content of this book. International Politics: Classic and Contemporary Readings, Second Edition seeks to help students engage critically with some of the world's most challenging questions through the use of leading classic and contemporary scholarship in the field of international relations. The first five chapters of the book explore the leading theoretical traditions in international relations, while subsequent chapters explore the themes of international security, international political economy, and contemporary challenges in international relations. This organization makes the book easy to use as standalone text or alongside core text. Class-tested on over 10,000 students in the last decade, this text was built from the ground up to introduce students to the traditions and new foundations of international relations as well to the principles of intellectually rigorous thought.