The nuclear non-proliferation regime, despite being frequently criticised for an alleged lack of effectiveness, is in fact an amazing success story. The number of states which had conducted nuclear weapons activities in various stages but which have terminated them at one point surpasses the number of Nuclear-Weapon States (NWSs) by far. At the apex of its success, however, the regime is threatened by erosion from three different directions. A small number of rule-breakers and outsiders undermine its central objective: to stop the spread of nuclear weapons. The refusal of the official NWSs to fulfil their undertaking of nuclear disarmament violates the principle of justice enshrined in the treaty and thereby destroys its legitimacy, as does the perceived readiness by nuclear suppliers to impede the development of nuclear technology in developing countries. The Gordian Knot can presumably only be cut by a u-turn towards a world without nuclear weapons. This insight has meanwhile reached the mainstream security establishment of the United States, the president included. Whether this road will really be taken will determine the future of the regime—with far-reaching consequences for global security.