Contributor(s): Professor Roy Allison | Russia and Western states have long clashed over the nature of international society and the desirability of a liberal rule-based international order. Relations plunged with Russia’s annexation of Crimea, which flouted a core prohibition of the United Nations Charter system against territorial expansion by force. Putin’s renewed all-out invasion of Ukraine now appears openly revanchist. This lecture assesses the implications for international order at large and the operation of international law, including international humanitarian law, around the conflict. It dissects the peculiar logic and false justifications Putin offers for Russia’s aggression. Does he really believe Russia occupies some common civilizational and territorial space with Ukraine, justifying the subjugation of Ukraine to return ‘historic Russian regions’? Or is this cynical cover for strategic ends aimed at the mobilisation of domestic support? With no end to the war in sight, the lecture also questions what remains of the post-Cold war territorial settlement in Europe and whether an eventual negotiated settlement of the war is conceivable under the current Russian leadership.