Neither science nor state has ever been transcendentally “neutral,” but they have sometimes been made neutral, together, as this paper shows in the context of cold war Europe. The paper explores how the Swiss government tried to “depoliticize” and “demilitarize” new international research institutions in the fi elds of highenergy physics (CERN), space research (ESRO and ELDO), and molecular biology (EMBL) in order to make science neutral. Conversely, this paper investigates how participation in “neutralized” scientifi c institutions supported Switzerland's neutrality policy and strengthened this essential element of its national identity. It thus addresses symmetrically the coproduction of neutral science and neutral state.