Do Arms Control Treaties Work? Assessing the Effectiveness of the Nuclear Nonproliferation Treaty

Abstract

How do international arms control treaties influence state policies? This paper investigates this question by analyzing the efficacy of the nuclear Nonproliferation Treaty (NPT). The effects of the NPT have been fiercely debated over the last several decades, but scholars do not yet fully understand whether the treaty "works." A debate about the treaty's effects persists in part because existing studies suffer from a key limitation: they are not designed to infer a causal connection between NPT membership and nuclear proliferation. Prior research cannot determine whether membership in the treaty restrains states from developing nuclear weapons or simply reflects existing preferences. To address this limitation, this paper accounts for selection effects by using a measure of states' ex ante treaty commitment preferences. Our analysis of nuclear proliferation from 1970 to 2000 provides evidence that the NPT has played a key role in curbing the spread of nuclear weapons. Even after accounting for strategic selection into the treaty, NPT ratification is robustly associated with a lower likelihood of pursuing nuclear weapons. Our results have broad implications for the study of how international institutions affect international politics.

Conflict and Cooperation on Nuclear Nonproliferation

“…Fourth, Fuhrmann & Lupu (2016) find a strong correlation between NPT ratification and nonproliferation. Yet, as they recognize, multiple mechanisms could generate this result.…”

Is the NPT unraveling? Evidence from text analysis of review conference statements

“…However, there is also substantial evidence for the success of the NPT. A number of quantitative studies find a negative correlation between the treaty and nuclear proliferation (Bleek, 2010;Bleek & Lorber, 2014;Jo & Gartzke, 2007;Fuhrmann, 2009;Horowitz & Narang, 2014), and this relationship holds even when controlling for a range of potential confounders and accounting for screening potential (Miller, 2014;Fuhrmann & Lupu, 2016). Treatymandated inspections of NNWS nuclear facilities, carried out by the International Atomic Energy Agency (IAEA), have caught states engaging in weapons-related activities that violated NPT commitments (Acton, 2009).…”

The Nuclear Fuel Cycle and the Proliferation “Danger Zone”

“…Despite some setbacks, the 1968 NPT codified a powerful norm of nuclear forbearance and some scholars have even identified a causal effect of participation on states' nuclear status (Fuhrmann and Lupu 2016). The Treaty distinguishes between the NWS and the non-nuclear-weapon states (NNWS) prohibited from developing nuclear weapons.…”