ABSTRACT
The character of international politics, the availability of military technology, and the effectiveness of nonproliferation measures all matter, but so do many other factors. Nuclear weapons acquisition is a complex and historically contingent process; its causes cannot be reduced to a single feature of international life. Proliferation pessimism and nonproliferation optimism provide unreliable forecasts because they rely on overly simplified notions of what drives and inhibits national nuclear weapons activities. The existing literature on the sources of proliferation is more rich than rigorous. The hypothesis that countries will acquire nuclear weapons if they are capable of doing so suffers from obvious empirical limitations. Power balancing is the oldest concept in the literature on international relations; it is central to neorealism. The nuclear myths of a state’s political and military leaders determine whether that state will launch a nuclear weapons program.
