In recent years, the nature of conflict has changed. Through 'asymmetric warfare' radical groups and weak state actors are using unexpected means to deal stunning blows to more powerful opponents in the West. From terrorism to information warfare, the West's air power, sea power and land power are open to attack from clever, but much weaker, enemies. In this clear and engaging introduction, Rod Thornton unpacks the meaning and significance of asymmetric warfare, in both civilian and military realms, and examines why it has become such an important subject for study. He seeks to provide answers to key questions, such as how weaker opponents apply asymmetric techniques against the Western world, and shows how the West's military superiority can be seriously undermined by asymmetric threats. The book concludes by looking at the ways in which the US, the state most vulnerable to asymmetric attack, is attempting to cope with some new battlefield realities. This is the first introductory textbook to focus on this increasingly important topic in security and conflict studies, and an entirely indispensable guide to one of the key topics in security studies today.