Radicalisation, Counter-radicalisation and Prevent offers a much-needed analysis of how 'ordinary' citizens make sense of 'radicalisation' as a security challenge, and how efforts to address this threat via counter-radicalisation initiatives are understood. Counter-radicalisation initiatives, such as the UK Prevent Strategy, are controversial and heavily critiqued by academics, the media, and community groups. Such criticism, however, remains limited because it rarely engages with the vernacular analyses of those potentially subject to such measures. To remedy this, the book draws on significant focus group research with students from universities across England and Wales to establish how radicalisation is understood in vernacular discourse; to explore competing understandings of the Prevent Strategy, its aspirations, and implementation; and to consider how those who have become a focus of the strategy feel about its design, implementation, and social consequences. The book shows that vernacular constructions of (counter-)radicalisation demonstrate important ambiguities and contradictions within commonly held assumptions about the meaning, possibility, and desirability of security policy. These ambiguities are vitally important not only for understanding counter-radicalisation and counter-terrorism, but for the study and practice of security more broadly. The book will therefore be essential reading for students, scholars and practitioners working on such issues across fields including Politics, Criminology, Law, International Relations, Sociology, and beyond.