During his academic career, he initially specialised in the issue of regional nationalisms and the recognition of new States. His current research focuses on the international system emerging from the war in Ukraine, the European Union’s capacity to become an autonomous actor in this context, particularly in the field of defence, as well as on European neighbourhood and enlargement policy. He particularly focuses on the differences that may exist between the older Member States and the countries of Central and Eastern Europe on these issues. He regularly speaks in the media and at conferences on these topics, as well as on issues related to Belgian and French politics.