The expansion of the fishing industry in the last century has raised concerns over the long-term viability of many fish species. International fisheries have failed to prevent the overfishing of many stocks but have succeeded in curtailing harvests for some key fisheries. This book develops a theoretical approach, the vulnerability response framework, which can increase the understanding of the countries’ positions on the management of international fisheries based on linkages between domestic vulnerabilities and national policy positions. Vulnerability, mainly economic in this context, acts as an indicator for domestic susceptibility to the increasing competition associated with open access and related stock declines. Because of this relationship, it can also be used to trace the trajectory of the countries’ positions on fishery management as they seek political alternatives to economic problems. The author tests this framework by using it to predict national positions for eight cases drawn from the International Commission for the Conservation of Atlantic Tunas (ICCAT). These studies reveal that there is considerable variance in the management measures which ICCAT has adopted—both among different species and in dealing with the same species over time—much of which can be traced to vulnerability response behavior. Little attention has been paid to the ways in which international regimes change over time. The book’s approach illuminates the pressures for change that are generated by economic competition and overexploitation in Atlantic fisheries, and also identifies patterns of adaptive governance, as national responses to such pressures culminate in patterns of change in international management.