Iran - US Relations from the Coup that Toppled Iran's Democratically Elected Government to the Assassination of Ayatollah Khamenei
Aug. 19, 1953: U.S. and Britain Topple Democratically Elected Government of Iran: It was the first covert action of the United States to overthrow a foreign government in peacetime. Prime Minister Mohammad Mosaddegh was overthrown in a coup d'etat in favor of strengthening the monarchical rule of Mohammad Reza Pahlavi ( "the Shah of Iran")
1953 - 1978 - The "reign of the Shah", characterized by autocratic rule, human rights abuses by his secret police, forced Westernization, and severe economic mismanagement.
1978 - A cycle of violent government crackdowns on religious demonstrations transformed local grievances into a massive, unified revolution. Protests against the Shah begin and intensify, peaking in December when more than 10% of the country marched in anti-shah demonstrations.
January 1979 - the Shah leaves Iran for Egypt
Feb 1 1979 - the exiled cleric Ruhollah Khomeini returns to Tehran greeted by a welcoming crowd of several million Iranians at the airport
October 1979 - Shah arrives in US for medical treatment
Nov 1979 - Iranian college students demanding extradition of the Shah take over the American Embassy precipitating a diplomatic standoff that lasted more than a year. US imposes its first sanctions against Iran.
1980-1988 - The Iran-Iraq War. The war starts when Iraq invades Iran. Many nations including the US provide political and logistic support to Iraq while Iran is relatively isolated. The war ends in a stalemate.
1985-86: Iran-Contra Affair creates a political crisis for Pres. Reagan.
1988 - The American warship USS Vincennes shoots down an Iran Air flight in the Gulf on 3 July, killing all 290 people on board. The US says the Airbus A300 was mistaken for a fighter jet. Most of the victims are Iranian pilgrims on their way to Mecca.
2002 - Bush's axis of evil speech, which lumps Iran with Iraq and North Korea, is met with outrage across Iran. An Iranian opposition group claims Iran is developing nuclear facilities.
May 2003 - Shortly after the U.S. invasion of Iraq, Iran sent a confidential proposal to Washington through Swiss diplomatic channels. The offer put all major bilateral issues on the table—including full transparency and limits on its nuclear program, and an end to support for regional militant groups—in exchange for U.S. security guarantees and an end to economic sanctions. The Bush administration rejected and ignored the overture
2002-2013 - Years of diplomatic activity and intermittent Iranian engagement with the UN's nuclear watchdog follow. Several rounds of sanctions are imposed by the UN, the US and the EU against ultra-conservative president Mahmoud Ahmadinejad's government. This causes Iran's currency to lose two-thirds of its value in two years.
2013 - Barack Obama initiates dialog with Iran's newly elected moderate president Hassan Rouhani
2015 - Joint Comprehensive Plan of Action - Iran agrees to limit its sensitive nuclear activities and allow in international inspectors in return for the lifting of crippling economic sanctions.
2018 - Trump withdraws from JCPOA and re-imposes sanctions in violation of the agreement.
May-June 2019 The US tightens the sanctions targeting Iran's oil exports. In response, Iran begins a counter-pressure campaign, which included controlled JCPOA violations, regional military signaling, declaring CENTCOM a terrorist organization, framing the U.S. sanctions as economic warfare and used the nuclear breaches to pressure Europe to deliver promised economic relief mechanisms.
May-June 2019 - explosions hit six oil tankers in the Gulf of Oman, and the US accuses Iran. Iran consistently denies the accusation.
June 2019 - Iranian forces shoot down a US military drone over the Strait of Hormuz. The US says it was over international waters, but Iran says it is over their territory.
January 3, 2020 - Iran's top military commander, Gen Qasem Soleimani, is killed by a US drone strike in Iraq. Iran pulls back further from the 2015 nuclear accord and on Jan 8 launches ballistic missiles at U.S. bases in Iraq (Al Asad and Erbil), injuring 110 U.S. service members
Aug 2020 — The U.S. tries to restore UN sanctions on Iran; 13 of 15 Security Council members reject the move as invalid because the U.S. had already left the JCPOA
2021–2022 — Nuclear deal revival talks stall. The Biden administration attempts to revive the JCPOA, but negotiations drag on and ultimately fail.
Sept 18, 2023 — Prisoner swap executed. Five Americans leave Iran; two Iranian prisoners arrive in Qatar.
June 10–11, 2024 — Tanker incident near Hormuz. U.S. Navy reports an alleged Iranian attack on the MV Helios; Iran denies involvement. UN Security Council holds an emergency meeting
Feb 2025 — Trump reinstates “maximum pressure”. New executive orders target Iran.
June 13–24, 2025 — Israel–Iran Twelve‑Day War. Israel and Iran fight a direct war; the U.S. provides significant defensive support to Israel.
June 22, 2025 — U.S. joins Israel in attacking Fordow, Natanz, and Isfahan nuclear sites — the first direct U.S. strikes inside Iran since 1979.
Feb 6, 2026 - U.S. and Iran begin mediated talks in Muscat, Oman, focusing on Iran's uranium enrichment, ballistic missile development, and regional proxy activities.
Feb 26 - Talks breakdown as US insists Iran completely dismantle its enrichment infrastructure or surrender its high-enriched uranium stockpile. Ayatollah Khamenei maintains that Iran would not yield its enrichment rights for peaceful purposes as agreed in the Treaty on Non-Proliferation of Nuclear Weapons, to which it is a signatory.
Feb 28 — Joint U.S.–Israeli operation targets Khamenei’s compound in central Tehran. The strike kills Ayatollah Ali Khamenei, several senior IRGC commanders, and members of his security detail. The US-Israel War on Iran begins.