Using or even merely threatening to use a nuclear weapon preemptively against a nonnuclear adversary tells the 182 non-nuclear-weapon countries signatories of the Nuclear Non-Proliferation Treaty that their adherence to the treaty offers them no protection against a nuclear attack by a nuclear nation. Many are thus likely to abandon the treaty, and the nuclear non-proliferation framework will be damaged even further than it already has, with disastrous consequences for the security of the United States and the world.