Driven by that fear, they took Herculean measures to fight and survive, no matter the odds or the costs. Others, whose experience and knowledge are at least as good as General Butler's, disagree. The actions of Stalin and his successors cannot be explained away as by-products of Western paranoia. There is every reason to believe that deterrence worked. In such instances as the Cuban missile crisis, the shadow of nuclear weapons led the superpowers to proceed most carefully or to step back from the brink of armed conflict.
Deterrence also seems to work in some regional situations.
Iraq, which had earlier used its chemical weapons against Iran and which had biological weapons ready, refrained from using them in the Gulf War, apparently because the US might have retaliated with nuclear weapons. By the Nuclear Nonproliferation Treaty of 1968, the United States and other nations subscribe to the elimination of nuclear weapons whenever international conditions and safeguards make that step feasible. At present, we are nowhere close to achieving such conditions and safeguards. Nuclear, chemical, and biological weapons of mass destruction continue to proliferate. Rogue nations want weapons of mass destruction because that is the easiest way for them to trump US conventional superiority.