A prolonged crisis between Iran and the USA. In the aftermath of Iran’s Islamic Revolution, followers of the Ayatollah Khomeini alleged US complicity in military plots to restore the Shah, Muhammad Reza Shah Pahlavi, and seized the US Embassy in Teheran, taking 66 US citizens hostage. All efforts of President Carter to free the hostages failed, including economic measures and an abortive rescue bid by US helicopters in April 1980. The crisis dragged on until 20 January 1981, when Algeria successfully mediated, and the hostages were freed. It seriously weakened Carter’s bid for presidential re-election in November 1980, and he lost to Ronald Reagan.