In Mission Manifest, Matthew Shannon argues that American evangelicals were central to American-Iranian relations during the decades leading up to the 1979 revolution. These Presbyterian missionaries and other Americans with ideals worked with US government officials, nongovernmental organizations, and their Iranian counterparts as cultural and political brokers—the living sinews of a binational relationship during the Second World War and early Cold War. As US global hegemony peaked between the 1940s and the 1960s, the religious authority of the Presbyterian Mission merged with the material power of the American state to infuse US foreign relations with the messianic ideals of Christian evangelicalism. In Tehran, the missions of American evangelicals became manifest in the realms of religion, development programs, international education, and cultural associations. Americans who lived in Iran also returned to the United States to inform the growth of the national security state, higher education, and evangelical culture. The literal and figurative missions of American evangelicals in late Pahlavi Iran had consequences for the binational relationship, the global evangelical movement, and individual Americans and Iranians. Mission Manifest offers a history of living, breathing people who shared personal, professional, and political aims in Iran at the height of American global power.