The border between Germany and Denmark is a result of the Versailles Peace Treaty implemented after the First World War. Drawn after a plebiscite in 1920, it was challenged until at least the 1950s by key actors within the respective national minorities on either side of the border and their nationalist supporters. Since the millennium, though, a narrative of reconciliation and cooperation has taken over, where national minorities’ institutions have taken in a central role of political bridge-building and de-bordering. The article will analyse the role of the German and Danish national minorities as secondary foreign policy agents in Danish–German relations in general and regional cross-border cooperation in particular. I argue that there is still a gap between rhetorics of involvement and factual governance, and that secondary foreign policy impact is heavily dependent on institutional capacity.