The United States and Iran have been engaged in an undeclared military conflict since the 1980s, with each side marking different starting points. For Americans, the conflict began in 1979 when Iranian students seized the US embassy in Tehran and held 52 diplomats hostage for 444 days. For Iranians, it began with US support for the Shah and subsequent backing of Iraq during the 1980-1988 Iran-Iraq war.
This long-running conflict has claimed many civilian lives. On July 3, 1988, the US warship Vincennes shot down Iran Air Flight 655, a civilian flight, killing all 290 people on board. More recently, on February 28, 2026, a US-Israeli missile hit a girls' school in southern Iran, killing over 150 civilians, mostly children. Iran also shot down Ukraine International Airlines Flight 752 on January 8, 2020, mistaking it for a US military flight, killing all 176 passengers.
The conflict escalated in the 1980s with the 'tanker war', when Iraq attacked oil tankers bound for Iranian ports. The US became involved after an Iraqi plane accidentally struck the American frigate The Stark in 1987, killing 37 crew members. The US then provided naval protection for Kuwaiti oil tankers, leading to direct clashes with Iran. Amid these hostilities, Iran Air Flight 655 was shot down, which ultimately brought Iran to accept a ceasefire ending the Iran-Iraq War, but not the conflict with the US.
After 2001, the Bush administration labelled Iran part of an 'axis of evil'. Following the 2003 invasion of Iraq, Iran supported Iraqi insurgents to target American forces. This proxy conflict wound down when US forces left Iraq in 2011. During the 2010s, the US and Iran fought a common enemy, ISIS, with the US providing air cover and Iran fighting on the ground. However, relations soured after the US withdrew from the Iran nuclear deal in 2018 and reimposed sanctions, leading to renewed hostilities with rocket attacks and air strikes.
