This chapter situates the book in the existing scholarship on (de)radicalisation and violent extremism. It traces the origins of the concept of radicalisation in its contemporary use in the context of the war on terror since 2001, and the introduction of the terminology of violent extremism a few years later. It also reviews the evolution of the research field in the last 15 years. It argues that most analysis has focused on individual and psychological dimensions of radicalisation, and there is still little consensus on how and why this process occurs. The chapter then delves into an integrative approach to radicalisation based on the complementarities of different fields and perspectives. As a result, a careful reading of common elements from psychology, identity theories, social psychology, and other fields and theories justifies the need for systemic approaches that also consider social conditions. On the preventive side, resilience has become a common approach and, for many scholars, represents the concept around which an agreement on how to address violent extremism is built. Although the concept and terminology of resilience are also subject to some criticism, the authors argue that a community resilience perspective is best positioned for effective prevention policies and strategies.