A considerable amount of research within security studies has explored the military's increasingly diverse and multifaceted tasks. However, this debate has been disconnected from the literature on civil-military relations to the effect that we still lack knowledge about how and why these operational tasks have consequences for the relations between the armed forces, civilian authorities, and society at large. In order to provide for a better understanding of these effects, this introduction to the Special Issue debates the concept of operational experiences to capture how the military's routine activities affect the equilibria, logics, and mechanisms of civil-military relations. The article then provides an overview of the Special Issue's six contributions, whose diverse and global perspectives shed light on different aspects of the relationship between military missions and the military's roles in society and politics. Among other factors, they highlight role conceptions – the military's shared views on the purpose of the institution – as crucial in shaping the dynamic relation between what the military does and what place it occupies within the state and society. The article concludes by describing potentially fruitful areas of future research.