Security Studies: An Introduction, 3rd edition, is the most comprehensive textbook available on the subject, providing students with an essential grounding in the debates, frameworks, and issues on the contemporary security agenda. This new edition has been comprehensively revised and updated, with new chapters added on poststructuralism, postcolonialism, securitization, peace and violence, development, women, peace and security, cybersecurity, and outer space. Divided into four parts, the text provides students with a detailed, accessible overview of the major theoretical approaches, key themes, and most significant issues within security studies. Part 1 explores the main theoretical approaches from both traditional and critical standpoints Part 2 explains the central concepts underpinning contemporary debates Part 3 presents an overview of the institutional security architecture Part 4 examines some of the key contemporary challenges to global security Collecting these related strands into a single textbook creates a valuable teaching tool and a comprehensive, accessible learning resource for undergraduates and MA students.