Like the pollution-control regimes described in Chapter 3, regimes designed to conserve natural resources must overcome conflicts among states’ economic and political interests, concerns for protecting state sovereignty, and different opinions regarding the importance of the precautionary principle and the principle of common but differentiated responsibilities (CBDR) and how to implement these principles. Moreover, natural resources regimes face the additional challenge of trying to protect resources and species that are of international importance but exist within the boundaries of sovereign states or beyond the boundaries of any state.