Contrary to expectations, fishing countries have established relatively effective management plans for a few international fisheries. The model described in this article explains how such multilateral regulation can evolve in spite of strong political and economic barriers to cooperation. Qualitative cases from the International Commission for the Conservation of Atlantic Tunas were used to test the model. Although there was not enough political will to maintain stocks at sustainable levels, fishing countries developed successful rebuilding plans for some overfished stocks. Developing countries played a critical role in this arena because the growth of their fleets provided incentives for developed countries to prefer stronger management. When powerful countries with high costs of production began to lose market share under open access, they turned to negotiated access rights in order to protect their fleets. This system also benefited developing countries when they garnered concessions and side payments for their cooperation.