Relying on personal interviews with senior officials in a dozen countries and never-before-released classified information, Bridled Ambition: Why Countries Constrain Their Nuclear Capabilities explains how and why nine countries - South Africa, Argentina, Brazil, Ukraine, Belarus, Kazakhstan, India, Pakistan, and North Korea - have capped, curtailed, or rolled back their nuclear weapons programs during the past few years. Their motivations varied. In the successors of the Soviet Union, for example, the end of the cold war eliminated the initial reason the weapons had been put in place, and new political, economic, and military uncertainties made it dangerous to maintain them. In South Africa, the anticipated transition to majority rule would put nuclear weapons in the hands of a longstanding, untrusted opposition. But in general, Reiss suggests, nuclear weapons may have come to be viewed as expensive and dangerous anachronisms. Reiss details the histories of the debates and politics of these nuclear programs. His account draws on interviews with more than 150 officials, on documentary evidence, and on journalistic accounts. In addition to the information brought forward on politics within the affected countries, Bridled Ambition includes information on the efforts and influence of U.S. diplomacy on these processes.