In the wake of the September 11 attacks, US officials identified the so-called battle for hearts and minds as the “second front” in the war on terror. A wave of funding flowed into public diplomacy in the Middle East, seeking to change views of the United States through Arabic-language communications—often while hiding the traces of American origins. To what extent did this vast propaganda apparatus sway Arab public opinion? Which ideas and actors shaped American public diplomacy in this period? What are the lessons for information strategy today? This groundbreaking book tells the story of American propaganda campaigns in the Middle East after 9/11, drawing on in-depth interviews with key players and previously classified documents. Nathaniel Greenberg shows how the United States tried to control perceptions of its response to 9/11 through news and entertainment, and reveals that Arab governments and unofficial actors were involved—knowingly or not—in distributing US propaganda. He explores the institutions, strategy, and rhetoric deployed in the war on terror, placing them in the context of American and Soviet influence campaigns during the Cold War. Greenberg argues that US government-backed broadcasting laid the groundwork for global information warfare, such as the rise of competing Russian and Chinese state media operations. Shedding light on the ideological underpinnings of American propaganda in Arabic after 9/11, The Long War of Ideas offers new insight into soft power in the twenty-first century.