Part I of this article provides a brief background of the United States takings jurisprudence. It examines how the Fifth Amendment protects private property rights and when environmental regulation implicates the payment of just compensation. Part II reviews the methods by which the United States government seeks to protect the environment without infringing on private property rights, focusing on financial incentives and disincentives. Part III compares the many parallels between private property rights and national sovereignty. Part IV explores how lessons derived from the United States experience in balancing private property rights and environmental concerns are relevant to international environmental issues. It focuses on how the United States seeks to influence the environmental policy of other states through financial incentives and disincentives in multilateral and bilateral contexts. Concluding that such conditional assistance is consistent with the domestic principle of just compensation, the article offers a framework for when such assistance is justified.