To the extent that the United States fails to pinpoint this in defining the purpose of nuclear weapons, that fear will be dull and its utility will be lost. Current U.S. policy regarding the use of nuclear weapons is not substantially different from its general Cold War policy. The United States maintains ambiguity about the circumstances under which it would resort to nuclear weapons. Despite growing and enduring U.S. conventional military superiority, even a nuclear response to conventional attack is not excluded. And yet, so unreal is the thought that the United States would use nuclear weapons in response to conventional attack that the current open-ended policy actually dulls deterrence.
Ambiguity is sometimes useful.
But in the new era, it does more harm than good. But that is not enough. To sharpen the fear to a finer point, the United States should also say that it foresees no need to use nuclear weapons except in response to attacks by weapons of mass destruction. In past efforts to stem the spread of nuclear weapons, the United States has said, in effect, that it would not use nuclear weapons against states that forswear them. In light of this danger, the United States should retract its pledge not to use nuclear weapons against any non-nuclear states.