The debate about the effectiveness of the Security Council in creating peace and security in the world is as old as the institution. For many years practitioners and scholars have discussed how factors such as the role of major powers, the unrepresentative structure of its permanent membership, or their veto power affect the Council’s impact on world politics. Such debates are legitimate and profoundly necessary, but in the present international situation a more fundamental challenge has arisen, that threatens the very foundation on which institutions like the UN are built: the assault on multilateralism and on the concept of a rules based international order that relies on cooperation among nations as its guiding norm. Unless that assault is effectively resisted, attempts at reforming or improving this or that international institution have scant chances of success.