The Politics of Preventing Violent Extremism explores how counter-radicalization policies have come to dominate European counterterrorism and security. Using interviews with practitioners across seven European nations, it documents how national security policies have been repurposed to identify individuals deemed ‘vulnerable’ to extremism and radicalization, and to provide targeted preventative interventions from welfare state agencies. Crucially, however, the methods (and limits) of preventing violent extremism (PVE) policies vary between nations. The Politics of Preventing Violent Extremism explores how political culture, the welfare state, and the conception of civil society in each nation shapes the type of counter-radicalization employed. While some European states have designed extensive pre-crime surveillance networks to identify those ‘radicalizing’ others, other states in Europe are bound by constitutional commitments to liberty of thought and speech which restrain them from using any type of pre-crime intervention. Accordingly, while PVE policies have been heralded as a novel solution to the problem of radicalization, they remain rooted in, and limited by, the political and social traditions of European democracies.