In this study, I examine the dilemmas arising from the tension between citizen duties and youthful aspirations in a globalizing world. The state's requirement of military conscription structures the transnational lives of young Korean male migrants. More particularly, the timeline for serving the duty works as a primary temporal reference for the males' initial migration planning and future projections. Drawn from ethnographic fieldwork and in‐depth interviews among a community of young Koreans in New Jersey, USA, my research reveals that their life planning in accordance with this institutional schedule is vulnerable to unexpected changes. The consequences are potentially detrimental to their futures, which not only differ from their individual ideals but also contain a high risk of marginalization both in Korea and in the USA. Building on the transnational migration literature, which focuses predominantly on spatiality, individual rights/agency and the marginalization of women migrants, I am concerned with temporality, citizens' duties and the constraints of masculinity as important parts of unravelling the complexities of transnational life.