Dwight Eisenhower demonstrated little interest in religion before and after his presidency. During his presidency, however, religion and religious symbols played an increasingly important role in the US public sphere, especially with regards to the fight against Communism. Three cases in particular—Iran, Guatemala, and Vietnam—show how religion became a tool in the formation and implementation of US foreign policy under Eisenhower's presidency. In each of these cases, religion was used to help establish regimes that quickly became ruthless and dictatorial. This historical experience should stand as a warning to Americans to be cautious and critical about the use of religion to achieve political or strategic objectives.