In strategic and security studies, the term « critical » has been applied to research that has successfully deconstructed dominant security practices and discourses over the last twenty years. In this article, I question the impact and the meaning of such labelling by dissecting it according to three scientific approaches. The first is ontological, where « critical » is a reflection of the broadening concept of security in the post–Cold War period. The second is epistemological, and deals with positivist–post-positivist debates in the field. The third has to do with intellectual engagement, which fuels recent works on the « criticality » of methods employed as well as on the contestation of security policies.