Can conscription help build national communities out of divided societies? Service in the armed forces can be a tool for socializing reluctant recruits into faithful citizens. But, in divided societies, officials might not recognize some groups as proper citizenship material; and some groups might not perceive the state as their own. Conscription then becomes a focal point for negotiations over the social contract between the state and liminal groups. We investigate these issues using a mixed-methods design applied to two paradigmatic cases in the Baltic Sea region, asking: Has conscription served as a tool for political socialization in post-Soviet Estonia (1990-present) and post-independence Finland (1917- 1945)? Previous literature suggests that even if the state entrusts marginalized groups – in our cases ethnic Russians and political “reds” – with positions in the armed forces, then their consent to the draft is contingent and its socializing effects remain uncertain. Building on data harvested from elite interviews and longitudinal conscript polls in Estonia, and from archival records and memoirs in Finland, we contribute with new evidence to this debate. Our project brings together academics from different disciplines, and different Baltic Sea countries, around a topic of enduring academic importance as well as practical significance to the future of this region.