The Iranian Revolution in 1979 led to the overthrow of the U.S.-backed Shah of Iran, Mohammad Reza Pahlavi, and the establishment of an Islamic Republic. The revolution was partly fueled by popular anger at the Shah's authoritarian rule and his close ties to the United States. Iranians saw the U.S. as a symbol of foreign interference in their country's affairs, and many resented the U.S. for its past support of the Shah's regime.
As a result of the revolution, a group of Iranian students and militants seized the U.S. embassy in Tehran in November 1979, taking 52 American diplomats and citizens hostage. The hostages were held captive for 444 days, with the captors demanding the return of the Shah, who was undergoing medical treatment in the United States.
The hostage crisis led to a deepening of hostilities between the two countries. The U.S. government imposed economic sanctions on Iran and severed diplomatic ties, while Iran became increasingly isolated from the international community. The U.S. also attempted a military rescue mission in April 1980, which failed and resulted in the deaths of eight U.S. servicemen.
The hostage crisis ended in January 1981, when Iran released the hostages minutes after the inauguration of President Ronald Reagan. The crisis had a profound impact on U.S.-Iranian relations and continues to shape the political and diplomatic landscape of the region to this day.