Which international incident helped Ronald Reagan defeat Jimmy Carter in 1980?

The Iran hostage crisis is the event that helped Ronald Reagan defeat Jimmy Carter for President of the United States in 1980. The Iran hostage crisis was a diplomatic standoff between the United States and Iran. Fifty-two American diplomats and citizens were held hostage for 444 days from November 4, 1979, to January 20, 1981.

Most political analysts cited the standoff in Iran as a major factor in the downfall of Carter's presidency and his landslide loss in the 1980 presidential election. The hostages were formally released into United States custody the day after the signing of the Algiers Accords, just minutes after American President Ronald Reagan was sworn into office.

In Iran the crisis strengthened the prestige of Ayatollah Ruhollah Khomeini and the political power of theocrats who opposed any normalization of relations with the US and other Western countries. This crisis was also one that led to American economic sanctions against Iran, which further weakened ties between the two countries.