International Relations (IR) knows itself as an American social science. The paper first traces how the self-image as a uniquely dividing and American social science was established in the postwar period and is reproduced to this day. Second, it employs bibliometric methods to challenge this image. It confirms the dominance of Americans in a comprehensive sample of IR journals, but in contrast to previous studies, the paper also compares IR to other disciplines only to find that it is actually one of the least American social sciences. It further studies the geography of IR over time and finds that IR has become less American since the 1960s—mainly because Anglo-Saxon and European countries account for a larger share of IR production. The final part uses novel visualization tools to map the geographical network structures of authorship and coauthorship in the discipline’s leading journals. By looking at cities and institutions, rather than national centers and peripheries, it finds a Western, rather than American, dominance materializing along the US coasts and in Western Europe and further expressed by most international coauthorships being Transatlantic. At the institutional level, it is even possible to identify a core-periphery structure within the American discipline. Finally, the paper uses the sociology of science to argue that IR is dominated by elite institutions, rather than Americans per se, and that further research on stratification in IR can provide a more nuanced approach to hegemony than the usual core-periphery metaphor.