It is not hyperbole to suggest that the foundations of post-cold war security in Europe have been badly damaged by the conflict in Ukraine since 2014. Russia's annexation of Crimea and intervention in eastern Ukraine appear to have created a 'simmering' conflict, which may take years to resolve and have profound consequences for the European security environment. This volume explores the various political, economic and social aspects of these profound changes and their wider significance for Europe, bringing together contributions by scholars from across the continent and in various disciplinary fields to offer an authoritative, in-depth examination of the complex causes of the Ukraine crisis and the consequences for Ukrainian statehood, Ukraine's relations with Russia, Russia's own domestic governance and Russia's relations with Europe. This book was originally published as a special issue of Europe-Asia Studies.