With the rise of the Islamic State of Iraq and Syria (ISIS), the issue of radicalisation has loomed large in Western policy debates. Recent summits on countering violent extremism have sought to highlight the importance of undermining extremist narratives, mobilising moderate Muslims who oppose ISIS and working to address drivers of radicalisation. This article explores the ideological underpinnings of this approach. It focuses on what I call the “Muslim paranoia narrative”, a recurring feature of Western radicalisation discourse that helpfully captures its ideological commitments and their contemporary significance. Analysing its manifestation in American political culture, I argue that the Muslim paranoia narrative indicates a powerful process of ideological reproduction that works against approaches to counter-radicalisation centred on engagement and collaboration with Muslim communities.