US and Iran: A brief history of how decades of mistrust and bad blood led to open warfare

An Iranian walks past an anti-U.S. mural in Tehran on April 5, 2025. Atta Kenare/AFP via Getty Images

With U.S. bombs raining down on Iran and Tehran’s leaders responding by hitting targets across the Persian Gulf and restricting transit through the Strait of Hormuz, it is fair to suggest that the present moment represents a low in relations between the two countries.

But the bad blood isn’t new: The U.S. and Iran have been in conflict for decades – at least since the U.S. helped overthrow a democracy-minded prime minister, Mohammed Mossadegh, in August 1953. The U.S. then supported the long, repressive reign of the Shah of Iran, whose security services brutalized Iranian citizens for decades.