U.S. policy makers are promoting U.S. civilian nuclear exports as a means of influencing the nonproliferation policies of foreign governments and of achieving U.S. nuclear nonproliferation objectives. This approach to nonproliferation policy making assumes that engaging in international civilian nuclear cooperation is effective at influencing partner country nonproliferation commitments and behavior, and that it is more efficient and effective than other means of achieving similar nonproliferation goals.

This dissertation tests these assumptions by examining the historical nonproliferation impact of U.S. civilian nuclear cooperation on three countries who sought to build civilian nuclear power programs with U.S. assistance: Japan, South Korea, and China. These case studies place U.S. civilian nuclear energy cooperation in the context of broader U.S. security and economic relations with these countries, and provide a nuanced understanding of each countries’ rationales for engaging in nuclear cooperation and nonproliferation in the first place. This dissertation also develops a novel approach to measuring nonproliferation that focuses on a country’s nonproliferation behavior in addition to its policy commitments. It also assesses whether particular types and stages of U.S. civilian nuclear cooperation and/or the characteristics of U.S. partners affect the strength and direction of the relationship between nuclear cooperation and nonproliferation.

In examining multiple periods of U.S. civilian nuclear cooperation with each country, this dissertation finds that U.S. civilian nuclear energy cooperation—and more specifically, the process of negotiating and renegotiating the terms of nuclear cooperation—can be effective ways to induce U.S. partner countries to adopt nonproliferation commitments. This is particularly the case when U.S. partners are energy insecure and rely predominantly (or exclusively) on foreign assistance in developing their civilian nuclear programs. U.S. civilian nuclear cooperation coupled with U.S. security cooperation (including nuclear security guarantees) can often win U.S. policy makers additional, detailed nonproliferation commitments from partner countries that are not possible with security cooperation alone.

The dissertation also finds that U.S. civilian nuclear cooperation has limited impact on the nonproliferation behaviors of U.S. partners in the short run once they formally make nonproliferation commitments. In all three cases, U.S. partners’ nonproliferation behaviors improve over time, but these improvements are due to the partners’ internalization of global nonproliferation norms and partners’ development of their own nonproliferation logic, rather than the influence of U.S. civilian nuclear cooperation. Frequent changes in U.S. nonproliferation preferences and, in particular, the divergence of U.S. nonproliferation preferences from the baseline tenets of the multilateral nonproliferation regime make it costly and difficult for the United States to maintain influence on partner countries’ nonproliferation commitments and behaviors over time with civilian nuclear cooperation.

On account of these findings, this dissertation argues that in many situations, U.S. civilian nuclear cooperation is not an effective means of achieving U.S. nonproliferation objectives. Compared to other possible courses of action, such as reinforcing multilateral nonproliferation agreements and norms, or engaging in nonproliferation capacity building, U.S. civilian nuclear cooperation is also not efficient in achieving U.S. aims. Should U.S. policy makers continue to pursue civilian nuclear cooperation as a means of achieving U.S. nonproliferation objectives, they should be aware of the conditions that are most conducive to U.S. nonproliferation influence, and they should be realistic about the challenges and costs associated with maintaining that influence over time.