This article explores a key period in the relationship between the United States and Iran in the shadow of the Vietnam conflict and the overarching Cold War. It shows how U.S.-Iranian relations shifted considerably from early 1965—when the shah of Iran stepped up his efforts to reduce his dependence on the United States—to November 1967, when U.S. economic development assistance to Iran formally ended. The Johnson administration's overwhelming concern with the Vietnam conflict led to the neglect of potentially critical foreign policy issues and allies, but the lack of success in Vietnam simultaneously accentuated the importance of maintaining key alliance relationships, especially with Iran. The article underscores the centrality of domestic political considerations in forming and understanding foreign policy, both in the United States and in other countries. It also suggests that Third World leaders understood the nature of the Cold War and used the superpower conflict to their advantage to a much greater degree than previously recognized.