The Russian invasion of Ukraine in February 2022 was a rupture point in European politics of a kind not seen since the collapse of the USSR in 1991. The effects on the human, military, energy and environmental security of Central and Eastern Europe have been dramatic, but ideational factors are proving to be as significant as material ones. Conflicting understandings of shared history are shaping the course of the war in Ukraine and its effects on the rest of Europe, underscoring the status of Russia as the other against which European societies construct their identity. As a result, in the rest of Europe as well as in Ukraine itself, Ukrainian identity is now increasingly seen as European, and European identity is understood to include Ukraine. At the same time, a collective focus on this reshaping of identity is muting some of the most urgent questions about the limits of European liberalism and democracy.