Quand l'expertise se heurte au pouvoir souverain : la nation américaine face à  la prolifération nucléaire, 1945-1953

After the Second World War, the applications of nuclear science raise a crucial threat to international security as far as their civil applications can be turned into military devices. Debates about nuclear proliferation offer a fruitful site to analyze the production of an expertise in bio-security. This paper analyzes in particular how experts have envisioned the role of nation-states and sovereign power in relation to policies aimed at ensuring the security of populations against the risk of nuclear annihilation. It explores what conceptions of sovereignty different experts constructed; what disciplines (political science, natural science, law) were mobilized in this debate; what strategies of institutionalization American experts followed; what publics were targeted by these experts (officials, think tanks, academic publics, media). Experts' conceptions of threats and insurances as well as the institutional paths they build to access policy circles explain which of the experts' policies diffused among policy circles. This approach, which focuses on the production of ideas rather than on the diffusion of administrative norms, complements neo-institutionalist studies of the internationalization of scientific modes of regulation.