This dissertation asks how far Americans in the twentieth century reconciled the demands of global supremacy with the claims and realities of democracy. As an answer, it offers the first history of the movement for citizen education in world affairs. This movement, loose but coherent, acted on the belief that since the United States was a mass democracy, the creation of an interested, informed public for foreign policy was essential to its peace and security. After World War I, members of the foreign policy elite resolved to teach Americans to lead the world, and they created a network of new institutions to do so. The most important and visible of these institutions was the Foreign Policy Association, a non-profit, non-partisan group founded by New York progressives in 1918 to support Woodrow Wilson in the fight over the Treaty of Versailles. By 1925, it had morphed into the first true foreign policy think tank in the nation, with a research staff creating new, public-facing knowledge and disseminating it to a broadening public. The research staff’s Foreign Policy Reports and Foreign Policy Bulletin gave information to diplomats, scholars, editors, businessmen, lawyers, and teachers, information that was otherwise inaccessible. As democracy was threatened at home and abroad during the Great Depression, the Association became more ambitious, founding branches in twenty cities to circulate foreign diplomats and a new breed of experts in international politics around the country. It pioneered broadcasts over the nascent national radio network, and tapped into a broader movement for adult education. With the encouragement of Franklin Roosevelt, a former member, the Association promoted intervention in World War II, and became a key partner of the State Department in the selling of the United Nations. Many members of the foreign policy elite believed that the rise of the United States to world leadership entailed new responsibilities for its citizens. As the prewar functions of the Association had been rendered obsolete, it resolved after 1947 to promote community education in world affairs, to make world leadership a part of daily life. Under the rallying cry of “World Affairs Are Your Affairs,” the Association partnered with the Ford Foundation to help create dozens of World Affairs Councils, most of them patterned on the success of the Cleveland Council on World Affairs. These Councils became a stage for international politics, bringing the world to cities across America, and those cities to the world. But by its own measurements, let alone the results of surveys or the intuition of officials, this movement to make every citizen a statesman failed. The Association and its subsidiary Councils remained weak, short on cash and beset by rivalries. Increasingly, they took refuge in an ever-smaller, educated, white elite, and, informed by social science, they wrote off ever more of the American electorate as uninterested or incapable when it came to world affairs. Very few Americans, it became clear by the early 1960s, were willing to dedicate themselves to world affairs on the model of citizenship that their leaders hoped, and to those leaders, the public therefore seemed fundamentally apathetic. The infrastructure that the foreign policy elite had spent decades building calcified, even before the traumas of the Vietnam War. A chasm developed between policymakers and the public, one that has proven impossible to bridge since.