After thirty-five years, the regime based on the Antarctic Treaty is more vigorous than ever. Here leading scholars of international law and international relations examine the effectiveness and legitimacy of this regime by asking two questions: are current changes affecting the ability of this regime to cope with major problems in the region, and how do those changes affect its standing among parties to the Treaty and in the wider international community? Individual chapters deal with Antarctic regimes for marine living resources, mineral activities, environmental protection and tourism. Throughout, a keen eye is kept on how these components interact and reinforce each other. This analysis is supported by in-depth studies of compatibility and tension between the Antarctic Treaty System and the international community at large. It also draws upon case studies of how domestic concerns and decision-making in four selected countries affect international cooperation in the Antarctic.