Survival of the best fit: modelling nuclear proliferation

Journal of Peace Research

2022

The nuclear competition school, an emerging theoretical perspective on the political effect of nuclear weapons, argues that a favorable nuclear balance can significantly reduce one’s expected costs of nuclear war and therefore affect the interaction between nuclear-armed states, such as deterrence and crisis outcomes. This new perspective also presents a wide array of empirical evidence demonstrating the significant effect of the nuclear balance of power on political outcomes, thereby challenging the theory of the nuclear revolution, which argues that the nuclear balance of power produces no meaningful effects on political outcomes because no state can escape costly nuclear destruction. Little attention, however, has been paid to systematically exploring the effect of the nuclear balance on the initiation of nuclear crises. This is surprising, given that observable factors, such as the nuclear balance, should have a powerful effect at the crisis initiation stage because countries can observe military balance and assess the costs and benefits of entering a crisis. This article tests a core argument of the nuclear competition school regarding the effect of the nuclear balance on the initiation of nuclear crises. With original data on strategic nuclear balance, my statistical analysis shows that having a superior nuclear arsenal than another nuclear-armed opponent does not lead to a reduced likelihood of nuclear crisis initiated by the opponent. These core findings hold after conducting a series of robustness tests with various measures of the balance of nuclear forces. They encourage us to reconsider the persuasiveness of the nuclear competition school and offer implications for US nuclear policy and force size.

Section: Discussionmentioning

confidence: 99%

Nuclear balance and the initiation of nuclear crises: Does superiority matter?

Journal of Peace Research

2022

“…On the one hand, my argument that assumptions about heterogeneity in dyadic data hugely affect our empirical conclusions echoes an emerging body of studies challenging the utility of quantitative approaches to understanding nuclear security issues. This literature argues that past quantitative studies often suffer from several problems, including poorly coded variables and the lack of sufficient robustness tests (Bell 2016; Montgomery and Sagan 2009), the failure to pay attention to heterogeneity across cases and the small-N problem (Gavin 2014), and the lack of careful consideration of the underlying assumptions of statistical models (Winter and Lenine 2020). On the other hand, it is the transparency of existing studies, one of the notable strengths of quantitative studies (Gartzke 2014; Fuhrmann, Kroenig, and Sechser 2014), that contributed to my reanalysis of Bell and Miller’s (2015) results by promoting reliable replication.…”

Section: Discussionmentioning

confidence: 99%

Does the Bomb Really Embolden? Revisiting the Statistical Evidence for the Nuclear Emboldenment Thesis

Journal of Conflict Resolution

2022

This paper revisits the latest statistical evidence for the nuclear emboldenment thesis—nuclear-armed states are more likely to initiate military aggression than non-nuclear states—from ( Bell and Miller 2015 ) recent study. If correct, their findings have important theoretical and policy implications regarding the effect of nuclear proliferation on international conflict. This paper shows, however, that Bell and Miller’s findings heavily rely on two important components of their statistical analysis: (1) using all state dyad observations, and (2) employing pooled regression models to analyze time-series-cross-sectional (TSCS) data. I argue that those components are based on questionable assumptions on heterogeneity in their dataset. Based on alternative strategies dealing with heterogeneity in dyadic data, my reanalysis shows that the emboldening effect of nuclear weapons is not as robust as originally claimed. Instead, I find the robust deterrent effect of nuclear weapons: nuclear-armed states are less likely to be targeted in military disputes. These findings highlight the need for careful application of quantitative methods to produce a more robust understanding of nuclear issues.

“…24.Other criticisms against quantitative research on nuclear weapons include inappropriate modeling assumptions (Winter and Lenine 2020) and questionable validity of existing findings (Bell 2016; Suh 2022). …”

mentioning

confidence: 99%

Achieving Minimum Deterrence: A New Dyadic Dataset on Strategic Nuclear Weapons Delivery Capabilities

Journal of Conflict Resolution

2023

This paper argues that existing quantitative studies mistakenly assume that all nuclear states can impose nuclear destruction on opponents by simply distinguishing nuclear states from non-nuclear states. This practice, however, does not capture variation in 1) nuclear states’ possession of delivery capabilities, 2) the range of deployed nuclear delivery systems, and 3) the geographic distance between nuclear states and their dyadic counterparts. Instead of this monadic nuclear statehood approach, I propose the dyadic nuclear reach approach, which uses a new dyad-specific measure of states’ strategic nuclear delivery capabilities. It codes whether a nuclear state can launch a nuclear strike against a given opponent by using the information about the estimated range of each nuclear state’s strategic nuclear delivery platforms, nuclear operation bases, and states’ capital cities. An empirical application shows that using an appropriate measure of nuclear capabilities does significantly alter existing empirical knowledge of nuclear weapons and international conflict.