The article explores France’s participation in international scientific and technological cooperation (ISTC) in the field of defense. It proceeds from the premise that the policy of France is characterized by variations between openness, which implies active participation in ISTC, and sovereignty, which means self-reliance in military research and development (R&D). The paper aims to identify the correlation between these two trends, as it uses the elements of comparative analysis and structural functionalism to study French and European documents on the ISTC in defense, and to summarize various interstate partnerships. It notes that on the European track, France counts on building a unified defense-industrial complex of the EU and promotes several types of cooperation with European neighbours, including direct supplies of ready-made weapons, joint development of advanced weapons, as well as the projects ensuring advanced integration of armed forces. Outside the EU, the ISTC is built around arms export: the case of India shows France’s readiness for a partial technology transfer. Simultaneously, the cooperation with the UK and Ukraine has gained momentum, but there is still a lot to clarify there. The article emphasizes that along with the ISTC, France resumes its own R&D (primarily on nuclear weapons), which can be explained by its uncertainty about the future of European defense integration, shortcomings of the formats in use, the activity of competitors, and the national tradition of military build-up. The article concludes that in the defense policy of France, sovereignty and ISTC (both within Europe and overseas) complement each other. Paris is likely to remain active on all the tracks discussed, although its ISTC with European partners mostly depends on political fluctuations.