This article proposes the political organisation of interstate integration – characterised by functional differentiation and unbundled multi-level territoriality – as a political ideal type. The theoretical foundations and empirical conditions of this new form of political organisation are explored focussing on basic security threats, such as nuclear armament, transnational terrorism, and organised crime. The empirical conditions of multilateral democratic integration are not essentially different from the conditions of democratic state-building and not limited to Europe. The political reality of multilateral integration is often misperceived in political theory. This is due, either to the uncritical presupposition of a traditional political ontology, defined by an essentialist understanding of the unitary state; or by an apolitical discourse on flows and scapes that loses sight of the specific features of political authority in the postnational realm.