Why do individuals sacrifice themselves to defend a nation-state? This article emphasises the link between emotion and culture by investigating the affective reproduction of culture in world politics. Building on the tradition of Émile Durkheim, it introduces the concept of emotion culture to IR. Emotion cultures are understood as the culture-specific complex of emotion vocabularies, feeling rules, and beliefs about emotions and their appropriate expression that facilitates the cultural construction of political communities, such as the nation-state. It is argued that emotions provide a socio-psychological mechanism by which culture moves individuals to defend a nation-state, especially in times of war. By emotionally investing in the cultural structure of a nation-state, the individual aligns him/herself with a powerful cultural script, which then dominates over other available scripts. The argument is empirically illustrated by the case of the so-called Japanese kamikaze pilots.