Why are there wars? Why do countries have a hard time cooperating to prevent genocides or global environmental problems? Why are some countries rich while others are poor? Organized around the puzzles that draw scholars and students alike to the study of world politics, this book gives students the tools they need to think analytically about compelling questions like these. World Politics introduces a contemporary analytical framework based on interests, interactions, and institutions. Drawing extensively on recent research, the authors use this flexible framework throughout the text to get students thinking like political scientists as they explore the major topics in international relations.