This book provides students with a fresh overview of the main theories of the state found in International Relations. Many International Relation scholars are proclaiming the state to be 'dead', while others lament the lack of an adequate theory of the state in International Relations. John Hobson seeks to resolve this confusion by introducing readers to state theory, arguing that existing theories of the state are limited, and proposing a new framework based around the 'agent-structure' debate. The book surveys realist, liberal, Marxist, constructivist and neo-Weberian approaches to the state, and places each perspective's view of the state in relation to its theory of International Relations as a whole. It offers readers a unique introduction to state theory in International Relations, and will be of interest to students and scholars of sociology and politics, as well as International Relations.