On 28 February 2026, Israel and the United States launched airstrikes on Iran targeting its nuclear program, striking more than 1,000 targets in the first 24 hours. An Israeli F-15I aircraft launched an air-launched ballistic missile from over international waters in the Red Sea to strike Supreme Leader Khamenei's compound in Tehran on February 28, killing Khamenei; Iran's Assembly of Experts confirmed Mojtaba Khamenei as the new supreme leader on March 8. US B-1 and B-52 bombers launched bombing missions from RAF Fairford, and KC-135R Stratotanker aircraft from RAF Mildenhall conducted aerial refueling over the Mediterranean after Britain agreed on February 28 to allow US aircraft to conduct defensive missions from British bases. Israel built a second secret military base in Iraq's western desert to support its strikes on Iran. Oman announced a breakthrough in US-Iran talks it had been mediating in the early hours of February 28, saying Tehran had agreed to zero uranium stockpiling and conversion of existing material into fuel, but the war began regardless. Israeli strikes hit oil refineries and depots near Tehran on February 28, causing fuel to seep into the city's water system and trigger explosions in residential areas. Tehran's municipal government released figures on May 16 showing US-Israeli attacks caused at least 650 impact incidents across the capital, killing more than 1,260 people and wounding at least 2,800. Iran struck Qatar's main gas facility at Ras Laffan on March 1, forcing Qatar to suspend LNG production in March.

Mass anti-government protests had spread across Iran in January 2026, fueled by economic woes, before the war began. Iran's official death toll rose to at least 3,375, including 383 children, and HRANA documented at least 3,636 fatalities, including 1,701 civilians. Iran estimated $270 billion in direct and indirect war damages. Iran's official statistics center reported annual inflation of 53.7 percent and food inflation of 115 percent in mid-April 2026, and Iran's rial fell to a record low of 1.9 million to the dollar on April 30. Iranian authorities imposed a near-total internet shutdown lasting more than 87 days and arrested more than 4,023 people between February 28 and May 9, executing 26 men considered political prisoners since the start of the war. On May 25, Iranian authorities executed Abbas Akbari over charges related to the nationwide anti-government protests in January. On May 26, Iran's President Masoud Pezeshkian ordered the restoration of internet access following the prolonged shutdown. On June 2, Marco Rubio stated that Mojtaba Khamenei was alive and increasingly engaging in regime affairs.

A Tomahawk cruise missile struck a school in Minab on February 28, killing close to 170 children; a Pentagon investigation on April 7 confirmed US responsibility, raising the confirmed death toll to at least 175. General Dan Caine confirmed on April 9 that 13 US service members were killed, with 373 wounded and more than 13,000 targets struck, destroying roughly 80 percent of Iran's air defenses, 90 percent of its navy, 90 percent of its weapons factories, and nearly 80 percent of its nuclear industrial base. A Congressional Research Service report confirmed on May 13 that the US lost or damaged more than 40 military aircraft during the war. US intelligence assessed on May 16 that 90 percent of Iran's underground missile storage and launch facilities remained partially or fully operational and that Iran retained approximately 70 percent of its pre-war missile stockpile. Pete Hegseth told lawmakers on May 13 that the war had cost Washington at least $29 billion in munitions and equipment over 74 days. On May 21, the US Navy paused a $14 billion weapons sale to Taiwan due to munitions shortages caused by the Iran war. On May 25, the US military launched new strikes on targets in southern Iran, hitting Iranian missile sites and boats attempting to place mines, killing three Iranians in a strike south of Lark Island on May 26. On May 27, the US military carried out a new round of strikes on an Iranian military site. Iran accused the United States of violating the existing ceasefire with those strikes and warned Washington would bear responsibility for all consequences.

Marco Rubio declared on May 5 that the offensive stage of Operation Epic Fury was over. The Trump administration prepared a fresh round of military strikes against Iran on May 22 but called them off over the weekend as diplomacy continued. Trump announced on May 18 that he called off a military strike on Iran planned for that Tuesday at the request of Gulf allies, and on May 20 postponed a planned attack after Gulf allies and his own officials warned him not to resume the war during the Hajj pilgrimage period. On May 21, Trump and Netanyahu clashed in a phone call over whether to resume strikes or give negotiators more time, and Israeli army chief Lieutenant General Eyal Zamir declared the Israeli military was on its highest level of alert.

Pakistan played a central diplomatic role throughout the conflict. The United States and Iran agreed to a two-week ceasefire brokered by Pakistani Prime Minister Shehbaz Sharif and army chief Asim Munir on April 8, extended indefinitely on April 21. On May 7, the US and Iran negotiated a one-page memorandum of understanding outlining a two-phase structure to end the war. Trump rejected Iran's May 10 response as totally unacceptable and dismissed Iran's revised May 18 proposal as garbage. Fars news agency revealed on May 18 the details of the US five-point peace proposal, including a demand that Iran keep only one nuclear site and transfer its highly enriched uranium stockpile to the United States. Pakistan's Interior Minister Mohsin Naqvi returned to Iran on May 21 for a second visit that week to continue mediation. Pakistani Prime Minister Shehbaz Sharif met Chinese President Xi Jinping in Beijing on May 25 to discuss the Iran peace negotiations.

On May 23, Trump announced that a memorandum of understanding in ceasefire talks with Iran had been largely negotiated and would include the reopening of the Strait of Hormuz. Also on May 23, Iran and Pakistan submitted a revised joint proposal to the United States. A high-level Iranian delegation including Foreign Minister Abbas Araghchi traveled to Doha on May 25 to discuss a peace agreement with the US and the release of frozen funds. On May 28, American and Iranian negotiators agreed on a 60-day memorandum of understanding pending Trump's approval, to extend the ceasefire and reopen the Strait of Hormuz; a US official told Axios that Trump relayed to mediators he wanted a couple of days to think about the agreement before signing it. Also on May 28, Trump pitched Gulf and Middle Eastern leaders on a phone call that all parties involved in the Iran deal would join the Abraham Accords by recognising Israel. Iranian President Masoud Pezeshkian stated on May 28 that Iran was not seeking nuclear weapons and that Iran did not engage in diplomacy with humiliation.

On May 29, Trump posted conditions for an Iran deal on Truth Social, including no nuclear weapons, an open Strait of Hormuz without tolls, mine removal, and US destruction of Iran's buried enriched uranium. Trump also announced on May 29 that he would lift the US naval blockade against Iran as part of any peace agreement. Iranian Parliament Speaker Mohammad-Bagher Ghalibaf declared on May 29 that Iran was ready for another round of fighting if ceasefire extension talks failed, and the Iranian parliament's national security commission chair Ebrahim Azizi denied reports about the possible transfer of Iran's enriched uranium stockpiles to a third country. On June 1, Iran suspended all peace negotiations with the United States through mediators, citing Israel's escalating attacks on Lebanon, and Iran and its allies declared their determination to completely block the Strait of Hormuz and activate the Bab el-Mandeb Strait as an additional front. Also on June 1, Iranian Foreign Minister Abbas Araghchi declared that the ceasefire covered all fronts including Lebanon and that Israeli violations there constituted a violation of the entire ceasefire, and Iranian Parliament Speaker Ghalibaf declared that Israel's actions in Lebanon amounted to US noncompliance with the ceasefire terms. On June 2, Trump posted on Truth Social calling reports that US-Iran peace talks had collapsed fake news and claiming the two countries had spoken continuously including that day. Also on June 2, Marco Rubio proposed that Iran should accept zero enrichment and dispose of its enriched uranium in exchange for the US lifting sanctions, and claimed Iran had agreed to negotiate aspects of its nuclear program it had refused to discuss a month ago.

On May 25, last-minute disagreements prevented a final Pakistani-drafted memorandum of understanding from being signed as hoped. Two regional officials confirmed on May 25 the specific terms of the draft memorandum of understanding: a 60-day ceasefire extension, immediate reopening of the Strait of Hormuz, a declaration ending all military operations on every front including Lebanon, Iran reaffirming it would never develop nuclear weapons, and Iran agreeing to dispose of its enriched uranium stockpile under a mutually agreed mechanism. On May 26, the emerging memorandum of understanding was clarified to exclude nuclear negotiations, with those talks deferred to a separate 30- to 60-day period after any initial agreement was signed. Iran's own draft initial agreement, revealed on May 26, encompassed an end to the war on all fronts, release of blocked Iranian assets, lifting of the US naval blockade, opening of the Strait of Hormuz, withdrawal of US forces from Iran's vicinity, and freedom to sell Iranian oil, with no nuclear commitments. Iran also demanded on May 26 the lifting of sanctions, release of tens of billions of dollars in frozen oil revenues, and reparations for war damage, and refused to discuss its ballistic missile programme.

A White House official said on May 24 that Iran agreed in principle to dispose of its highly enriched uranium stockpile. On May 26, Trump announced that Iran's enriched uranium stockpile could be destroyed inside Iran under international nuclear agency oversight, a significant shift from earlier US demands for transfer abroad. Russia offered on May 25 to take Iran's highly enriched uranium as part of the emerging deal. The IAEA confirmed on May 25 that Iran held 440.9 kilograms of uranium enriched up to 60 percent purity. Iran's Foreign Minister Abbas Araghchi rejected claims that Iran had agreed to send enriched uranium abroad or accept a cap on enrichment for 10 years. Pakistan publicly rejected on May 25 Trump's demand that multiple Middle Eastern countries join the Abraham Accords as a mandatory condition of the Iran peace deal. A senior Trump administration official said on May 25 that the US understood that Supreme Leader Mojtaba Khamenei had endorsed the broad template of the emerging deal. On June 2, IAEA chief Rafael Grossi visited the Barakah Nuclear Power Plant in the UAE and offered technical support following the May 16 drone attack on the facility.

The IRGC declared on March 4 that it was in full control of the Strait of Hormuz. Iran suspended oil tanker transits through the strait on April 9 and laid sea mines in main transit routes. Trump announced a blockade of all Iranian ports on April 14. The US launched Project Freedom on May 4 to escort commercial ships through the strait, but it collapsed after approximately 50 hours on May 6. Iran reached a deal with China on May 13 allowing a large number of oil tankers bound for China to transit the strait. Iran's Supreme National Security Council announced on May 18 the formation of the Persian Gulf Strait Authority, and on May 21 the authority announced a formal supervision area requiring vessels to obtain permission before transiting. On May 28, Iran began charging up to $2 million per vessel for safe passage through the Strait of Hormuz, justifying the fees as war reparations and payment for navigational services; Gulf countries rejected the transit fee scheme. Maritime intelligence firm Kpler reported on May 23 that 38 commercial vessels had been hit in and around the Strait of Hormuz since the start of the conflict. Britain's Royal Navy prepared the RFA Lyme Bay at Gibraltar on May 24 for a mine-clearing mission in the Strait of Hormuz, contingent on a peace deal being reached. On June 1, Kuwait activated its air defences and denounced Iranian missile and drone attacks as undermining regional de-escalation efforts. On June 3, an Iranian drone struck Kuwait International Airport's passenger building, wounding multiple people and prompting Kuwait to suspend commercial flights. On June 2, Marco Rubio stated that the US naval blockade was costing Iran hundreds of millions of dollars a day in lost oil revenue. On June 2, Marco Rubio said NATO's response to the Iran war called into question the utility of US membership in the alliance.

Saudi Arabia launched numerous secret airstrikes against Iran toward the end of March 2026, and the UAE carried out secret bombing raids on several Iranian sites in early April 2026. Iran targeted the UAE with more than 2,800 drones and missiles over the course of the war. Saudi Arabia floated on May 18 a non-aggression pact between Iran and Middle Eastern states. The UAE quit OPEC on May 1 and announced on May 15 it would complete a new oil pipeline bypassing the Strait of Hormuz by 2027. On May 25, the UAE and Israel established a joint fund for defence acquisition.

The Dallas Fed described the Iran war on May 8 as the largest geopolitical oil supply shock on record. Brent crude oil hit $122 per barrel in late April 2026 before settling at $103.50 per barrel on May 11. The US Labor Department reported on May 12 that the consumer price index rose 3.8 percent year-on-year in April 2026, with the nationwide gasoline average reaching $4.50 per gallon. Trump announced on May 12 that he would suspend the federal gasoline tax. Brent crude oil prices fell approximately 5 percent on May 25 as peace deal signals remained mixed, then surged approximately 3.5 percent to $100 a barrel on May 26 as US-Iran peace hopes faded following new US strikes on Iranian missile sites. On May 29, Brent crude oil prices slipped 0.8 percent to $91.97 a barrel as US-Iran ceasefire optimism grew, and Asian stock markets mostly rose on hopes of a ceasefire extension. Wall Street pushed to record highs on May 28, with the S&P 500 setting an all-time high. On June 1, Brent crude oil prices surged 6.7 percent to $97.28 per barrel after Iran suspended peace talks and threatened to close the Bab el-Mandeb Strait. The International Energy Agency warned on May 26 that the full economic repercussions of the Iran conflict would not be felt until the end of the year.

Hezbollah launched missile attacks on Israel on March 2, triggering Israel's ground invasion into southern Lebanon. Israel launched Operation Eternal Darkness on April 9, killing more than 300 people in a Beirut airstrike. By May 25, Israel occupied approximately 235 square miles of territory in southern Lebanon. Lebanon and Israel extended their ceasefire by 45 days on May 16 following US-mediated talks in Washington. Despite the extension, Hezbollah carried out 26 attacks against Israeli forces in southern Lebanon on May 20 and 24 attacks on May 21. On May 25, an Israeli airstrike in the village of Mashghara in the Bekaa Valley killed at least 11 people, including a woman and two children. On May 25, Netanyahu ordered the Israeli military to escalate strikes on Lebanon and crush Hezbollah. On May 28, Israel bombed Beirut for the first time in three weeks, marking the second attack on the Lebanese capital since the April ceasefire. On May 29, Netanyahu stated Israeli forces had crossed the Litani River and were operating in Beirut, the Bekaa Valley, and across the entire Lebanese front. On June 1, the Israeli military issued a forced displacement order for residents of the southern Beirut suburbs of Dahiye and ordered strikes on the area. Lebanon's Ministry of Public Health reported on May 26 that Israeli attacks had killed at least 3,185 people and wounded 9,633 others since March 2, with more than 1.2 million people displaced. Trump told Netanyahu on May 24 that he would not sign any final Iran agreement without conditions that Iran dismantle its entire nuclear program and give up all enriched uranium, while Netanyahu warned Trump that Israel maintained freedom of action against threats in all arenas, including Lebanon.

The war deepened fractures within the Western alliance and in US domestic politics. Italy declined on March 28 to allow US bombers to land at Sigonella base without parliamentary approval, and Spain refused on May 8 to allow the US access to two joint military bases. Republican Senators Lisa Murkowski and Susan Collins both voted on May 13 in favor of a war powers resolution against the Iran war. The House voted 212-212 on a Democratic war powers resolution on May 14, failing for the third time. A New York Times/Siena poll published on May 19 found that two thirds of US voters believed Trump's decision to go to war with Iran was wrong, consistent with a Washington Post-ABC News-Ipsos poll published on May 7 that found 66 percent of Americans disapproved of Trump's handling of the war.