Why are there wars? Why do countries struggle to cooperate to prevent genocides or global environmental problems? Why are some countries rich while others are poor? Organised 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. In the second edition, two new chapters - one on civil war and terrorism and one on international law - bring the book's successful approach to additional topics. Added features stress real-world applications and provide extensive study and review help, making the authors' analytical approach even more accessible and engaging.