Iran-U.S. War: Timeline & Latest Developments

The US-Iran war traces back to the collapse of a nuclear negotiation process that had run, on and off, since April 2025. Talks in Muscat and Rome that spring stalled over one core disagreement: Washington wanted Iran to dismantle its uranium-enrichment program entirely, while Tehran insisted on retaining some domestic enrichment capacity under inspection. A fresh negotiating track opened in February 2026, mediated by Oman with Qatar, Egypt and Turkey joining as co-mediators, and produced an Iranian offer to dilute its enriched-uranium stockpile in exchange for full sanctions relief. A fourth round scheduled for Vienna never happened. On February 27, President Trump ordered US forces to proceed with a strike campaign later named Operation Epic Fury, and at 06:35 UTC on February 28, 2026, US Central Command announced it had begun airstrikes on Iran alongside Israeli forces, opening what is now tracked as the 2026 Iran war.

Iran has consistently characterized its own role in the war as defensive rather than aggressive. President Masoud Pezeshkian has said Iran’s attacks on US bases are “purely defensive,” aimed at protecting Iranian territory and people rather than expanding the war, and has argued that Iran’s missile arsenal is what prevented the country from suffering “the fate of Gaza.” Tehran’s public conditions for ending the war, stated in March, are guarantees against future attacks, recognition of what it calls Iran’s legitimate rights, and reparations. This is Iran’s own stated position, not an outside assessment of it, and it sits alongside, not in place of, the fact that Iran’s retaliatory strikes have hit targets well beyond the US military bases the war’s opening strikes targeted, including Gulf airports and a diplomatic post.

The opening 12 hours set the pattern for the months that followed: overwhelming US and Israeli firepower, Tomahawk cruise missiles from Navy ships and submarines, HIMARS and long-range standoff weapons from Army units, and B-2, B-1 and B-52 bomber sorties against Iran’s ballistic-missile infrastructure, paired with immediate Iranian retaliation against the wider US regional footprint. Iran struck four bases hosting US personnel within hours: Al Udeid in Qatar, Ali Al Salem in Kuwait, Al Dhafra in the UAE, and the Fifth Fleet’s facility in Bahrain. The war’s US casualty toll began accumulating almost immediately and has continued in waves rather than a single front line: six Army Reserve soldiers killed in a drone strike on a Kuwait port facility on March 1, fifteen troops wounded in an Iranian strike on a Saudi air base on March 27, and a Navy helicopter crew lost in a non-combat accident in the Arabian Sea as late as July 1. US military deaths stand at 18, 17 soldiers and one contractor, with 553 wounded, as of early July.

Iran’s toll is far larger and far less precisely known, a gap that itself reflects the two governments’ different relationships with public casualty data. Iran’s own government puts total deaths, military and civilian combined, at 3,482, with 26,500 injured, according to its Health Ministry. Human Rights Activists in Iran (HRANA), a US-based independent human-rights NGO that has tracked the war since its opening days, documented 3,636 deaths as of April 7, including 1,221 military personnel and 1,701 civilians, and cautioned in its own reporting that military casualties are “believed to be significantly higher” than it can confirm, because its access to Iranian military locations is limited. US and Israeli military intelligence estimates go further still, putting Iranian military deaths at 6,000 or more with roughly 15,000 wounded, figures that are themselves unverified claims from a combatant government about the enemy it is fighting, not an independent count, and should be read with the same caution applied to any other state’s claims about its own military’s results.

This is a page specifically about the bilateral US-Iran dimension of a wider regional war that also runs through Israel, Lebanon, and the Gulf states; the parallel Israel-Iran track, including the killing of Iran’s Supreme Leader Ali Khamenei in the opening strikes and the multi-front missile barrages that followed, is tracked separately. What belongs here is what Washington did, what Tehran did back to US forces and US-linked infrastructure, and the diplomacy between the two governments specifically.

That diplomacy has produced two negotiated ceasefires, and two collapses. The first, brokered by Pakistan on April 8 after Trump threatened to destroy Iranian infrastructure over the closed Strait of Hormuz, held only nominally: the strait stayed effectively closed the very next day, follow-on talks in Islamabad broke down on April 12, Trump extended the pause on April 21 citing a “seriously fractured” Iranian government, and by May the US had shifted to active “Project Freedom” naval patrols that periodically exchanged fire with Iranian boats even as the ceasefire technically remained in force. The second, negotiated through June and formalized June 17 when Trump signed the Islamabad Memorandum during a dinner with French President Macron at the Palace of Versailles, with Iranian President Masoud Pezeshkian signing remotely from Tehran, was the most substantive agreement of the war to date: a 60-day ceasefire, a reopened Strait of Hormuz, phased sanctions relief and the outline of a $300 billion reconstruction fund tied to a permanent treaty still to be negotiated. It lasted three weeks before breaking down in two escalating waves.

On July 6, three commercial tankers were attacked in the Strait of Hormuz. Iran did not claim responsibility, but the US and several Gulf states blamed Tehran, and on July 8 Trump declared the ceasefire over and ordered strikes that US Central Command said eventually hit more than 170 Iranian targets, a US battle-damage claim not independently confirmed. Iran answered with missiles and drones against Jordan, Kuwait and Qatar. Three days later, on July 11, an Iranian attack on the container ship M/V GFS Galaxy in the strait triggered a still-larger round of US strikes, a US-reported 140-plus targets, and Iran’s broadest single retaliatory action of the war: coordinated missile and drone attacks against five Gulf states, Jordan, Oman, Qatar, the UAE and Bahrain, overnight into July 12. As of this writing, President Trump has called the Versailles agreement “a waste of time,” Iran maintains a unilateral, functionally unenforced claim that the Strait of Hormuz is closed, and neither government has announced a third ceasefire attempt.

The throughline across four and a half months is that every US-Iran ceasefire in this war has broken on the same fault line: the Strait of Hormuz, and Iran’s periodic assertion of a right to threaten or close it, against a US posture that treats any disruption to that shipping lane as grounds to resume strikes. Until that specific dispute is resolved, rather than merely paused, the pattern this page documents, ceasefire, strain, tanker incident, collapse, looks likely to repeat.