This paper explores understandings of military duty in contemporary international intervention. The concept of military duty is increasingly complex in unfolding global security dynamics. Western armed forces, principally trained, socialized and tasked with fighting wars with the use of force are now expected to conduct ‘population-oriented’ interventions to protect local populations at risk. In a context of increased regional instability, which has renewed focus on national security, military defense, and the reinstatement of conscription in several European states, a number of European armed forces nevertheless continue to deploy elsewhere to conduct military operations that address the political and security concerns of host nations. Coexisting calls of duty to defend at home and protect populations abroad raise a number of questions, including how do host citizens feature in military members’ understandings of military duty? Informed by the literatures on military intervention and cohesion, the study draws on semi-structured interviews with Swedish military members with experiences of international deployment to illustrate the relational qualities of military duty, and specifically explore the role of obligations to host citizens. In doing so, the study identifies a number of tensions between the general idea of military duty as principally defined by a commitment to national defense and the strength of interpersonal bonds and loyalties within the military organization, and military members’ sense of duty––perceived obligations––in the context of mission deployment.