The open access book aims at discussing the manifold consequences that the War against Ukraine bears for the European Union and EU Studies. It takes stock of the fact that the Russian Attack on Ukraine and the ensuing War not only affects the Global Order, but also has challenged a number of established narratives and convictions for the European Union and its member states. The EU now needs to position itself in the changing world order. Concretely it needs to deal with a number of membership applications, internal and external challenges to liberal democracy, and the development of its strategic autonomy in a number of decisive policy fields. The book convenes experienced scholars, with chapters covering the following themes and fields: Theories, approaches and concepts in EU studies and IR; the EU and the changing European and Global Order; the War and defence of liberal democracy; Membership Politics; Energy Policy.