The thought of Norberto Bobbio provides an original and consistent contribution to studies of IR, peace theory, and European integration studies. On the one hand, he was stressing a point that has become fashionable in recent developments of research in neo-institutionalism concerning international cooperation and peace by developing a theoretical framework based on references to two concepts that typically belong to the realist tradition: anarchy and hegemony. On the other hand, he offered a distinctive approach to the study of EU integration and the EU institutional system as a topic in political science in his articles on political theory, notably with his emphasis on the link between domestic and continental federalism, as well as on the notion of a «mixed constitution».