Twenty-five years after the indefinite extension of the Nuclear Nonproliferation Treaty (NPT), Joseph F. Pilat revisits the question of what a world without this cornerstone agreement would come to look like. Today, the Treaty and the NPT regime face serious challenges and its next Review Conference is expected to be contentious. Pilat argues that the NPT regime is not perfect, but the entire world has a stake in the regime’s continued implementation and traces why from his perspective.