Mainstream analyses of radicalisation, which are disproportionately focused on individual psychology and pathology, are fundamentally inadequate for explaining the phenomenon. Approaches such as the UK’s Prevent strategy consistently depoliticize extremism, treating it as a security issue divorced from the wider workings of society while ignoring the material conditions that fuel dissent. This book argues for a systemic shift in perspective, grounding the analysis of radicalisation within a Marxist framework. It posits that extremism is not a product of ‘deviant’ minds but a rational, albeit destructive, response to the structural violence inherent in global capitalism. Drawing on historical materialism, the analysis reframes radicalisation as a consequence of class domination, neoliberal austerity, and imperial legacies that produce profound inequality and social alienation. By examining how Islamist extremist and far-right networks exploit the contradictions of racialized capitalism, such as labor exploitation and cultural erasure, the book challenges policymakers to abandon flawed individualist paradigms. It offers a materialist framework for understanding radicalisation as both a form of resistance to, and a reproduction of, oppressive systems, bridging academic and policy debates to confront the systemic roots of political violence.