Andrew J. Coe

Collusion and the Nuclear Nonproliferation Regime

We present a theory of the origins and enforcement of the nuclear nonproliferation regime based on a game-theoretic model of proliferation. The theory synthesizes the popular, but incomplete, views of the regime as a grand bargain or a cartel. Widespread nonproliferation is only possible if the superpowers collude to coerce some states into compliance, as in the cartel, but this enforcement is only affordable if most states voluntarily comply under a grand bargain. This collusion arises from the superpowers’ early experience of proliferation and its disruptive effects on intra-alliance politics. We document collusion in the negotiation and enforcement of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and find support for the theory’s predictions in a data set of superpower reactions to states’ failure to join or comply with the NPT. Our theory implies that the regime has substantially reduced proliferation, in contrast to previous studies’ findings.

Arms Diffusion and War

The authors present a model of the relationship between the spread of new military technologies and the occurrence of war. A new technology could shift the balance of power, causing anticipatory war as one side tries to prevent the other from obtaining it. When one side already has it, war is more likely when the shift in power is large, likely, and durable. When neither side has it, war is more likely when the expected shift is asymmetric (e.g., one side is more likely to get it) and when the two sides fear that a war will occur once one of them has it. The authors illustrate the model with historical examples from the spread of firearms (the Musket Wars in precolonial New Zealand) and of nuclear weapons (the end of US nuclear monopoly and the 1967 Six-Day War). A broader implication is that major power competition can unintentionally cause wars elsewhere.

A Dynamic Theory of Nuclear Proliferation and Preventive War

We develop a formal model of bargaining between two states where one can invest in a program to develop nuclear weapons and the other imperfectly observes its efforts and progress over time. In the absence of a nonproliferation deal, the observing state watches the formers program, waiting until proliferation seems imminent to attack. Chance elements—when the program will make progress and when the other state will discover this—determine outcomes. Surprise proliferation, crises over the suspected progress of a nuclear program, and possibly “mistaken” preventive wars arise endogenously from these chance elements. Consistent with the models predictions and contrary to previous studies, the empirical evidence shows that the progress of a nuclear program and intelligence estimates of it explain the character and outcomes of most interactions between a proliferant and a potential preventive attacker. Counterintuitively, policies intended to reduce proliferation by delaying nuclear programs or improving monitoring capabilities may instead encourage it.

North Korea's new cash crop

If Pyongyang can no longer use its nuclear program to extort aid from the international community, rising economic pressures on the Kim Jong‐il regime may force it to sell its nuclear resources to one or more of a number of dangerous customers.

Containing Rogues: A Theory of Asymmetric Arming

Weak opponents of a strong state often cannot compete directly with its power and so resort to other means of shifting the balance of power, such as developing weapons of mass destruction, sponsoring foreign terrorism or insurgency, or undertaking regional aggression. I develop a formal model of bargaining between a state that might seek unconventional means to power and another that might try to prevent this by diplomacy, war, or containment. The standard bargaining problems of commitment and asymmetric information give rise to costly conflict, but the form of this conflict is determined by the cost effectiveness of containment versus war. I calibrate the model to the situation of the United States and Iraq after the Gulf War and derive from it a new account of the Iraq War’s origins based on evidence that the anticipated costs of containment came to exceed those of war, causing the war.