The United States and Iran have lacked formal diplomatic relations since April 7, 1980, following the seizure of the U.S. embassy in Tehran and the hostage crisis that lasted 444 days. Since then, Pakistan has acted as Iran’s protecting power in the United States, representing Iranian interests in Washington, while Switzerland serves as the U.S. protecting power in Tehran.
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The opening strikes of the 2026 Iran war killed Iran’s Supreme Leader Ali Khamenei, triggering a regional escalation that remains ongoing as of September 2026.
From Allies to Adversaries
Before the severance of diplomatic ties, the U.S. and Iran maintained relations dating back to the late 19th century, with formal diplomatic ties established in 1883. Relations remained largely cooperative throughout much of the 20th century, particularly during the reign of the Shah of Iran, Mohammad Reza Pahlavi, who maintained a close alliance with the United States. The 1953 CIA-backed coup that ousted Iran’s prime minister Mohammad Mossadegh left a lasting impact on the relationship, shaping Iranian suspicions of American intentions. The 1979 Islamic Revolution then overthrew the Shah’s government and established the Islamic Republic of Iran, a regime that positioned itself in opposition to U.S. influence, and the hostage crisis that followed introduced a period of hostility that has persisted for more than four decades.
Sanctions, Diplomacy and the 2015 Nuclear Deal
U.S. policy toward Iran has shifted among several postures over the decades, ranging from attempts to engage diplomatically to periods dominated by economic sanctions and military deterrence. Tensions escalated intermittently through incidents such as support for opposing factions in regional conflicts, disagreements over Iran’s nuclear program, and military confrontations in the Persian Gulf. The Joint Comprehensive Plan of Action, signed in 2015, briefly reduced tensions by curbing Iran’s nuclear program in exchange for sanctions relief, but ultimately collapsed, setting the stage for renewed conflict.
The 2026 War
Tensions boiled over on February 28, 2026, when the United States and Israel launched a surprise bombing campaign against Iran, carrying out nearly 900 strikes in 12 hours against missile sites, air defenses, military infrastructure and leadership targets, even as diplomatic talks between Washington and Tehran were still underway. The opening strikes killed Iran’s Supreme Leader, Ali Khamenei, triggering hundreds of retaliatory missiles and thousands of drones launched from Iran across the Middle East. Iran responded by striking Israel and U.S. military bases in Bahrain, Kuwait, Qatar, the United Arab Emirates, Saudi Arabia, Jordan and Iraq, and imposed a partial blockade of the Strait of Hormuz. On March 2, the war expanded into Lebanon, reigniting the conflict between Hezbollah and Israel, which launched a ground invasion of southern Lebanon. As of September 2026, the conflict remains ongoing, with continued tension in the Strait of Hormuz and an escalating civil war in Yemen tied to the broader regional fallout.
