This widely acclaimed textbook offers a comprehensive introduction to the theories that underpin the study of international relations. Each chapter, written by an expert in the field, explores a different theoretical tradition—ranging from realism, liberalism, and Marxism to constructivism, feminism, postcolonialism, the English School, and green theory. The editors emphasize that theory is not just an academic exercise, but a vital tool for explaining and interpreting the dynamics of world politics. The book positions theory at the heart of international relations, showing how different perspectives illuminate issues like war, peace, power, justice, and global governance.

The latest editions include new chapters on emerging approaches such as global IR, reflecting the growing importance of diverse and non-Western perspectives in the discipline. Each chapter features real-world case studies that bridge theory and practice, encouraging readers to apply theoretical insights to current political dilemmas. Spotlights on key books and articles help students deepen their research and critical thinking skills, while online resources support both students and instructors with revision guides, web links, and teaching materials.

Through its accessible structure and commitment to diversity, the book opens up space for debate and analysis, allowing readers to engage with both dominant and marginalized voices in the field. It encourages critical reflection on the development of international relations as a discipline and highlights the importance of viewing global politics through multiple, sometimes competing, theoretical lenses.