The events of 9/11 appeared to make good on Ulrich Beck's claim that we are now living in a (global) risk society. Examining what it means to ‘govern through risk’, this article departs from Beck's thesis of risk society and its appropriation in security studies. Arguing that the risk society thesis problematically views risk within a macro-sociological narrative of modernity, this article shows, based on a Foucauldian account of governmentality, that governing terrorism through risk involves a permanent adjustment of traditional forms of risk management in light of the double infinity of catastrophic consequences and the incalculability of the risk of terrorism. Deploying the Foucauldian notion of ‘dispositif’, this article explores precautionary risk and risk analysis as conceptual tools that can shed light on the heterogeneous practices that are defined as the ‘war on terror’.