Since the advent of the nuclear age, scholars have sought to provide rationales behind decisions to pursue, forgo, or relinquish nuclear weapons programs. Security, status, cost, technical capabilities, and domestic considerations have played central roles in explaining those choices. Classical neorealism was once the conventional wisdom, advancing that relative power and the logic of self-help in an anarchic world drove states to nuclear weapons. Yet, the analysis of nuclear proliferation has evolved in accordance with broader debates in international relations theory in recent decades, including the incorporation of neoliberal institutionalist, constructivist, and domestic political perspectives. The end of the Cold War and the upheaval of international order in particular marked a watershed for the literature, with scholars challenging the dominant paradigm by examining the effects of institutions, norms, and identities. Those approaches, however, under-theorized—if not omitted altogether—the role of domestic political drivers in choices to acquire or abstain from acquiring from nuclear weapons. Such drivers provide filters that can be invaluable in explaining whether, when, and how state actors are susceptible to considerations of relative power, international institutions, and norms. More recently, scholars have deployed more sophisticated theoretical frameworks and diverse methodologies. The road ahead requires greater analytical flexibility, harnessing the utility of classical perspectives while adding enough nuance to increase explanatory power, greater attentiveness to the complex interaction among variables, and improved specification and operationalization amenable to rigorous testing, all with an eye toward enhancing both historical accuracy and predictive capabilities.
Wilfred Wan and Etel Solingen
Molly Berkemeier and Matthew Fuhrmann
This essay reviews academic research on the role of nuclear weapons in foreign policy. It begins by discussing the “Theory of the Nuclear Revolution,” which holds that nuclear weapons revolutionized world politics due to their overwhelming destructive capacity. The article then identifies several ways in which this theory has been challenged in scholarship. The article focuses in particular on four big debates in the literature on nuclear weapons and foreign policy: Does nuclear proliferation promote international peace and stability? Are nuclear weapons useful for coercive diplomacy? Do nuclear weapons make countries more assertive? How does nuclear strategy influence deterrence and security? After discussing these debates, the article concludes by calling for more research on the implications of dual-use nuclear technology for foreign policy and international security.
Paige Cone and Rupal N. Mehta
What has the academic scholarship found to date on the role of inducements, external incentives, or punishments to change the behavior of states in the international system? To understand the role of inducements in international relations, it is imperative to explore the full package of options, often referred to as “carrots and sticks” that are available in foreign policy decision-making to best understand when and why certain inducements are successful and why some may be more so than others. There are two big debates of policy importance to note here: Can nuclear decision-making be influenced by external actors, such as the United States? And, second, which set of tools are most helpful to the state seeking to change the behavior of another: carrots, sticks, or some combination of both? Although both incentives and punishments are generally used to change behavior in interstate relations, there are unique policy levers in the nuclear arena that scholars have recently begun to explore. The literature on inducements directly impacts ongoing policy debates, which in turn ultimately highlights the need for more research on nuclear-specific inducements. This article offers the first in-depth, systematic analysis of these inducement options, starting with their general use and then focusing specifically on inducements in the nuclear proliferation arena.
Rupal N. Mehta and Rachel Elizabeth Whitlark
What will nuclear proliferation look like in the future? While the quest for nuclear weapons has largely quieted after the turn of the 21st century, states are still interested in acquiring nuclear technology. Nuclear latency, an earlier step on the proliferation pathway, and here defined as operational uranium enrichment or plutonium reprocessing capability, is increasingly likely to be the next phase of proliferation concern. The drivers of nuclear latency, namely security factors, including rivalries with neighboring adversaries and the existence of alliances, are especially consequential in an increasingly challenging geopolitical environment. Though poised to play a significant role in international politics moving forward, latency remains a core area of exploration and subject of debate within the nuclear weapons literature writ large. While in many ways similar to nuclear weapons’ proliferation, the pursuit of nuclear latency has distinct features that merit further attention from scholars and policymakers alike.
Game theory is a set of mathematical tools used to analyze the strategic interaction between decision makers. Proponents of game theory have offered different perspectives about its potential benefits in the study of politics: It is a rigorous apparatus that can offer a solid foundation for the scientific enterprise; it offers predictions that could be tested with statistical analysis; it can account for the essence of unique cases and could be tested with qualitative evidence. Critics of game theory, in political science and international security specifically, argued in the 1990s that it had generated few empirical insights. Two decades later, game-theoretic approaches to international security remain a robust research program, but their prevalence remains limited. It is important to evaluate the potential benefits of game theory and the contributions that it has made to international security, so as to devise appropriate strategies to maximize its empirical purchase. The controlled comparison approach, using qualitative evidence on a medium number of cases, appears especially promising.
Frank C. Zagare
Perfect deterrence theory and classical deterrence theory are two theoretical frameworks that have divergent empirical implications and dissimilar policy recommendations. In perfect deterrence theory, threat credibility plays a central role in the operation of both direct and extended deterrence relationships. But credible threats are neither necessary nor sufficient for deterrence to prevail, and under certain conditions, the presence of a credible threat may actually undermine deterrence. In perfect deterrence theory, the cost of conflict and status quo evaluations are also important strategic variables. Classical deterrence theorists tend to fixate on the former and ignore the latter. This theoretical oversight precludes a nuanced understanding of the dynamics of deterrence.