In their December 4 National Interest article, Adam Lowther and Hunter Hustus assert that, when it comes to nuclear weapons, “less is not just less, less is different”, in order to cast doubt on the wisdom of reducing U.S. strategic nuclear forces below the level set by the New Strategic Arms Reduction Treaty (New START). “Less” may become “different” at some point, but it is hardly the case now, when the United States and Russia each have at least ten times as many nuclear weapons as the country with the third largest nuclear arsenal.
Lowther and Hustus note that the U.S. nuclear arsenal exists not just to deter attack on the United States but also to extend deterrence to U.S. allies in Europe and Asia. Extended deterrence is a more demanding task: an adversary may very well believe the United States would respond with nuclear weapons to an attack on American territory, but that same adversary may question whether Washington would so readily use nuclear weapons to defend an ally if that raised a risk of a nuclear attack on the United States.
Lowther and Hustus write that the Iranian and North Korean nuclear programs could create pressures on other countries, e.g., Saudi Arabia, to acquire their own nuclear weapons. These pressures would increase if doubts over the credibility of the American extended deterrent grew. Extended deterrence is not just about deterring the adversary but, equally importantly, about assuring allies.