Theory meets intellectual history in this new and expanded edition of International Relations Theory. Long known for its concise presentation of the various images and interpretive understandings of how to approach the complexity of international politics, this edition devotes a significant portion of the book to the intellectual precursors who have informed current perspectives on international relations. The discussion moves well beyond the usual cannon of Thucydides, Machiavelli, and Hobbes by linking them and other writers to present-day IR theory—realism, liberalism, economic structuralism, and English School images; as well as constructivist, feminist, postmodern, and critical theory lenses. This unique approach enhances our abilities to think conceptually and critically not only about how our 21st-century world of diverse state and non-state actors works, but also the implications of the changes we observe domestically and globally.