Drawing on methodologies from Performance Studies and Transnational American Studies, this dissertation is an historical analysis of the transatlantic relations of the American Indian radical sovereignty movement of the late Cold War. First the study recovers the transnational dimension of Native Americans as historical actors, and demonstrates that the American Indian radical sovereignty movement of the early 1970s posed a transnational challenge to the U.S. nation state. Next, arguing against the scholarly consensus, it shows that by the mid-1970s the American Indian radical sovereignty movement transformed itself into a transnational struggle with a transatlantic wing. Surveying the older transatlantic cultural representations of American Indians, this study finds that they both enabled and constrained an alliance between Native radical sovereignty activists and European solidarity groups in the 1970s and 1980s. This dissertation traces the history of American Indian access and participation in the United Nations, documents the transformation of Native concepts of Indian sovereignty, and analyzes the resulting alliances in the UN between American Indian organizations, Third World countries, national liberation movements, and Marxist régimes. Finally, this study documents how national governments such as the United States and the German Democratic Republic responded to the transatlantic sovereignty alliance from the middle of the 1970s through the end of the Cold War.