The severing of diplomatic relations between the United States and Iran marked a significant moment in U.S.-Iran relations, largely influenced by the Iran hostage crisis that began in November 1979. Following the Iranian Revolution, a group of Iranian students seized the U.S. embassy in Tehran, taking 52 American hostages. This act was rooted in long-standing grievances against U.S. involvement in Iran, particularly the 1953 coup that reinstated the Shah. As the crisis unfolded, the hostages were held for 444 days, leading to widespread outrage in the U.S. and a strained relationship between the two countries.

In early April 1980, after several failed attempts at negotiations and increasing frustrations over the hostage situation, the U.S. government decided to formally sever diplomatic ties with Iran. Secretary of State Cyrus Vance announced the action, which included recalling its ambassador and imposing additional sanctions on Iran. This decision escalated tensions further, as diplomatic avenues were closed off and the possibility of military intervention became a topic of discussion within the U.S. administration.

By cutting off relations, the U.S. signaled its determination to not tolerate the hostage crisis or the actions of the Iranian government, leading to further isolation of Iran on the international stage. The ensuing years would witness strained U.S.-Iran relations, characterized by economic sanctions, military confrontations, and political rhetoric that has continued to shape Middle Eastern geopolitics.