The landmark Treaty on the Non-Proliferation of Nuclear Weapons (NPT) came into force in 1970 and was indefinitely extended in 1995. Its twofold aim was nonproliferation and general disarmament: to prevent the spread of nuclear weapons to new countries and to eliminate them in countries already holding them. Success has been partial, at best, as a handful of new countries have joined the “nuclear club” and the major nuclear powers retain vast arsenals. The world has been fortunate that well-documented miscalculations and near-misses have not triggered a devastating nuclear exchange. So far. The recent saber-rattling by Kim Jong-un and Donald Trump underscores the failure of both pillars of the NPT as a new nuclear power defies the non-proliferation objective and an old one disregards the disarmament aspiration. Moreover, the bellicosity and unpredictability of these leaders makes the presumption of rational actors, which underlies conventional nuclear deterrence doctrine, much less tenable. That alone seems reason enough to move the Doomsday Clock closer to midnight. In the short run, the vital check of diplomacy must reassert itself. In the long run, we must return to the vital work of advancing the Zero Option: a world without nuclear weapons.