Extending democratic processes beyond borders is possible, particularly in civil society settings. This research project identifies deliberative diplomacy as a promising format, a new form of public diplomacy based on deliberative discourse, i.e. relying on the force of the better argument in favor of the common global good. A comprehensive analysis of the »Going Green« sustainability school project of the Embassy of the United States of America in Berlin, Germany, provides empirical evidence. Furthermore, the analysis identifies a specific window of opportunity in transatlantic relations that allowed this new phenomenon of international democratic exchange to evolve and also elaborates on its theoretical underpinnings in democratic and IR theory. Thanks to its rare insight on the attitudes of adolescents concerning transatlantic relations, environmental sustainability, and deliberation, this book is a significant contribution to the study of deliberation and civic education.