DOES PROLIFERATION BEGET PROLIFERATION? WHY NUCLEAR DOMINOES RARELY FALL

Abstract

If Iran acquires nuclear weapons, or merely the capacity to do so on short notice, will other regional states attempt to acquire them as well? If North Korea does not give up, enlarges, or further weaponizes the modest nuclear arsenal it appears to have already acquired, will others follow suit? More broadly, is the conventional wisdom that "proliferation begets proliferation" correct? And if so, under what conditions is such "reactive proliferation" more or less likely, and therefore what tools might policymakers in Washington and elsewhere have to forestall further proliferation?

This dissertation examines these questions using both quantitative and qualitative approaches. Hazard analysis, a statistical method of examining risk over time and its relationship to various factors, is employed on a new dataset of the proliferation behavior of all states throughout the nuclear age. Quantitative findings are further explored qualitatively, via in-depth case studies of two states that both had very intense rivals proliferate, Pakistan and Egypt.

The analysis finds that states whose security rivals proliferate consequently experience modest increases in proliferation motivation. These modest increases are sufficient to push many over the low thresholds to exploring nuclear weapons options. But, sharply contra conventional wisdom, they are not sufficient to push most over the far higher thresholds to launching nuclear weapons programs or seeing such programs through to acquisition.

Variation in reactive proliferation outcomes is explained in part by three sets of intervening variables. These also highlight conditions under which greater reactive proliferation can be expected and therefore levers policymakers in third party states may be able to employ to make reactive proliferation even less likely.

First, policymakers perceive nuclear weapons in rival hands as primarily defense dominant and status quo-reinforcing, although somewhat less so when exceptionally intense rivals proliferate. Second, because states derive only a modest proliferation impulse from rival proliferation, states facing lesser economic costs and technological challenges are more likely to reactively proliferate. Third, while some states have powerful allies that both resist their proliferation and can extend security guarantees to them, others are more independent and hence more likely to reactively proliferate.