The Dangers of Nuclear Proliferation: Five Reasons More May Not Be Better

Though many international relations theorists have speculated that the spread of nuclear weapons may diminish the frequency -- if not the severity -- of military conflict among states, there are five reasons to expect that increased proliferation will increase the likelihood that nuclear weapons will be employed for coercive or destructive purposes. These dangers are independent of one another; that is, they are not interconnected as causes and effects. First, as nuclear weapons spread, the notion that these weapons are useful for purposes other than deterrence will spread concomitantly. Those who argue that the spread of nuclear weapons will diminish conflict wrongly assume that the leaders of new nuclear states will consider nuclear weapons useful only for deterrence. Second, actors within states may support policies that undermine deterrence stability. Specifically, such actors could support the deployment of weaponry and other technologies that could -- in certain strategic contexts -- provide incentives for pre-emptive attacks by one side or the other. Third, one side of an inter-state rivalry may acquire nuclear weapons long in advance of its vulnerable adversary. Often, the leaders of states that enjoy such advantages contemplate attacking their rival before it can acquire nuclear weapons, too. Fourth, though new nuclear states will be assumed to be as careful with their weapons as the older nuclear states, proliferation may nevertheless cause the probability of such accidents to grow at an accelerating rate. As the number of nuclear states increases, the distances between these states decrease, and some of them may assume dangerous launch-on-warning force postures to compensate for their perceived vulnerability to sudden attack. Launch-on-warning increases the danger that accidents could escalate into nuclear violence. Fifth, surreptitious attempts may be made by third parties to instigate nuclear war between other states. The likelihood that the provocateur of such an incident would remain undiscovered increases as the number of nuclear states grows -- as does the temptation to instigate such an event