Abstract
Russia's invasion of Ukraine is an extraordinarily serious violation of the prohibition on the use of force that was embodied in Article 2.4 of the UN Charter after a long historical process. The fact that it was perpetrated by one of the permanent members of the Security Council implies a breach of the consensus among the Allies in World War II that gave rise to the United Nations and the system of international peacekeeping and security that it brought with it. The final outcome of the war in Ukraine may mean that the blow to the system of collective security envisaged in the Charter may be fatal, should the outcome be favourable to Russian interests, or that, despite being badly damaged, it may continue to exist, should the final outcome of the conflict be favourable to Ukrainian interests.
