How can the mechanisms of using political communication for building or tearing down borders be described theoretically and empirically, referring to examples from the present and the past? Which kinds of communicative tools and strategies do different political actors use to build or tear down borders? Which transnational, cross-border patterns of such forms of political communication do we find around the world? Which contextual conditions favor or hinder the use of political communication for building or tearing down borders? Which methods do we need to investigate questions like these?