Even if universal in human activities, uncertainty is often absent from weapons procurement studies. Despite pioneering works of Scherer and Peck that recognize uncertainty as a main characteristic of weapons acquisitions, academic works that follow often do not investigate this feature in depth. Indeed, weapons procurement studies generally do not consider uncertainty as a crucial factor in explaining why weapon programs fail completely or encounter costs overrun, delays, and deficiencies in delivered capabilities. Explanations range very often from technologically overly ambitious military service’s technological over-ambitions to the deficient procurement strategies of their respective bureaucracy’s deficient procurement strategy. In this paper, we will go further in explaining why some programs fail to produce new weapon systems with in terms of costs, delays and capabilities. As the majority of academic works about weapons acquisition consider the U.S. case, we will bring some change by focusing on the French military establishment.