During the 1920s and 1930s thousands of European and American writers, professionals, scientists, and artists came to record their impressions of the "Soviet experiment". The interwar pilgrimage of these Western intellectuals and fellow-travelers remains one of the most notorious episodes in political and intellectual history. Showcasing the Great Experiment, incorporating far-reaching analysis of the declassified archival records of the agencies charged with crafting the international image of communism, brings this story into new focus as one of the great cross-cultural and trans-ideological encounters of the twentieth century. While many visitors were profoundly affected by their Soviet tours, so too was the Soviet system itself: the early experiences of building showcases and teaching outsiders to perceive the future-in-the-making constitute a neglected part of the emergence of Stalinism at home. This pioneering work of transnational history develops a new framework for understanding how and why many of the twentieth century's greatest writers and thinkers, including Henri Barbusse, Theodore Dreiser, Lion Feuchtwanger, and Andre Gide, among others, ardently defended Stalin's USSR despite the unprecedented violence of its prewar decade. Probing little-known, covert entanglements between far-left and far-right ideological extremes, the work pays special attention to Soviet attempts to recruit and cooperate with far-right nationalists, including German "National Bolsheviks, " fascist intellectuals, and even members of the Nazi Party. The Soviet preoccupation with molding Western public opinion resulted in an influential contribution to the history of modern cultural diplomacy. Setting the revolutionary regime's innovations against the context of the treatment of foreigners in Russia from Muscovy on, Showcasing the Great Experiment argues that interwar Soviet methods mobilizing the intelligentsia for the international ideological contest directly paved the way for the cultural Cold War.