The structural changes inside the French innovation system have impacted the role of defense firms since the late 1980s. Major changes have affected the defense budget and public R&D funding system in particular. The aim of this article is to understand French defense firms' repositioning within the National Innovation System (NIS) based on an analysis of their R&D behavior over a long period of time (1987 to 2010). We show that French defense firms remain major players in the NIS and faced up to these major changes by adapting the funding of their R&D and their research priorities and rolling out new innovation capabilities. Additionally, they developed new innovation models to take advantage of new collaborative partnerships developed for civil and military markets.JEL classification: G32, 032