Shipping traffic through the Strait of Hormuz, a major maritime choke point for world energy trade, has been largely blocked by Iran since 28 February 2026, when the United States and Israel launched an air war against Iran. In retaliation, the Iranian Revolutionary Guard Corps (IRGC) issued warnings forbidding passage through the strait, boarded and attacked merchant ships, and laid sea mines in the strait. From 13 April to 29 May 2026, the US simultaneously blockaded Iranian ports. Until the war's start, about 25% of the world's seaborne oil trade and 20% of the world's liquefied natural gas (LNG) passed through the strait.
Soon after the start of the conflict, the number of tankers trafficking the strait dropped near zero. On 27 March, the IRGC announced that the strait was closed to any vessel going "to and from" the ports of the US, Israel, and their allies. The International Maritime Organization reported on 21 April that about 20,000 mariners and 2,000 ships were stranded in the Persian Gulf due to the closure. Amid fears of prolonged supply shortages, oil prices rose faster than during any other conflict in recent history; Brent crude oil prices surpassed US$100 per barrel on 8 March for the first time in four years, rising to US$126 per barrel at their peak. The largest-ever monthly increase in oil prices occurred in March 2026. The closure of the strait became the largest disruption to world energy supply since the 1970s energy crisis as well as the largest in the history of the world oil market. Other commodity markets to suffer supply disruption and price increases due to the crisis include aluminum, fertilizer, and helium.
In late March and early April, US president Donald Trump repeatedly threatened to destroy Iran's infrastructure if it did not reopen the strait. On 8 April a temporary ceasefire between Iran and the US was agreed and was to involve the reopening of the strait. However, following the failure of the Islamabad Talks, the US Navy itself began to blockade Iranian ports from 13 April. The situation was described by The Guardian as a "dual blockade", with the US Navy blockading Iran and Iran blockading the Gulf. On 17 April, Iran announced that due to an Israel–Lebanon ceasefire agreement, it would allow commercial shipping, but the US continued its blockade of Iran, and Iran reimposed restrictions. On 4 May, Trump launched Operation Project Freedom, a US Navy mission to escort merchant ships out of the Gulf. The Iranian military warned that this would be a ceasefire violation, and on 6 May, Trump paused Project Freedom because of "great progress" toward a possible agreement.
On 17 June, Trump and Iranian president Masoud Pezeshkian signed a memorandum of understanding to end the war and the blockades of the strait. On 19 June, Trump announced a renewed ceasefire between Israel and Hezbollah, facilitated by the US, Qatar, and Iran. However, Israel continued strikes in southern Lebanon, and the following day, Iran said that it closed the strait again, citing the Israeli actions as a violation of the agreement, a claim denied by the US military. On 27 June, the Joint Maritime Information Center (JMIC) overseen by the US Navy announced a widened route through the Strait of Hormuz near Oman, allowing increased naval traffic in both directions and indicating a challenge to Iran's control over the waterway. On 8 July, the interim truce agreement between the US and Iran broke down after Iran struck multiple commercial ships in the Strait of Hormuz. On 25 August, US officials confirmed Trump's claim that the US Navy cleared mines from the Strait of Hormuz Traffic Separation Scheme, adding that over recent months, underwater drones identified over 100 suspected mines and private contractors dealt with them. Trump stated that the US will destroy Iranian vessels laying additional mines in the Strait of Hormuz.
As of 21 October, the Middle Eastern oil exports, including shipments through the Strait of Hormuz and alternative routes, had averaged more than 24 million barrels per day in the week ending 18 October, exceeding the pre-war level of 23.3 million, according to Kpler. However, preliminary estimates put flows through Hormuz, including offshore transfers in the Gulf of Oman, at approximately 14 million barrels per day, or 82% of pre-war levels. Despite the recovery in exports, shipping costs remained high.
Background
Global oil trade
The strait is 34 kilometres (21 mi) wide at its narrowest point, forming a seaway passage between Iran and Oman. Its two unidirectional sea lanes facilitate the transit of around 20 million barrels of oil per day, representing roughly 20% of global seaborne oil trade, primarily from Saudi Arabia, the United Arab Emirates, Iraq, and Qatar. In 2024, an estimated 84% of crude oil and condensate shipments through the strait were destined for Asian markets, with China receiving a third of its oil via the strait, and had about a billion barrels in oil reserve (a few months of supply). Europe gets 12% to 14% of its LNG from Qatar, through the strait.
The Persian Gulf is also a major hub for global fertilizer production and exports. In the 2020s the region has accounted for roughly 30% – 35% of global urea exports and around 20% – 30% of ammonia exports. Overall, up to 30% of internationally traded fertilizers normally transit the Strait of Hormuz.
Geopolitical tensions
Tensions between Iran and the United States resulted in the 1988 Operation Praying Mantis, included some European countries in the 2011–2012 Strait of Hormuz dispute, and again in 2019.
Tensions between Iran, the United States, and Israel escalated in the lead-up to 2026, stemming from failed nuclear negotiations in Geneva and a prior 12-day air conflict in 2025. Iran had signaled potential disruptions to the Strait of Hormuz in response to threats, including a temporary partial closure earlier in the month as a warning. From 15 to 20 February, Iran increased its oil export to three times its normal rate and reduced oil storage to reduce risk of disruptions. Saudi Arabia also attempted similar moves. In the days before the strikes, war-risk ship insurance premiums for the strait increased from 0.125% to between 0.2% and 0.4% of the ship insurance value per transit. For very large oil tankers, this is an increase of a quarter of a million dollars.
In briefings held before the February 2026 attacks, the Joint Chiefs of Staff warned President Trump that an attack could prompt Iran to close the strait. Trump acknowledged the warnings, but dismissed the possibility, telling his team that Iran would likely capitulate instead of closing the strait, and if they did, the US military could open it again.
Escalation
On 28 February 2026, the United States and Israel initiated coordinated airstrikes on Iran under Operation Epic Fury, targeting military facilities, nuclear sites, and leadership, resulting in the death of Supreme Leader Ali Khamenei. Iran responded with missile barrages on Israeli cities and US bases in the Gulf, including in the UAE, Qatar, and Bahrain, causing casualties and infrastructure damage. The conflict expanded to Lebanon, where Iran-backed Hezbollah launched rockets into Israel, prompting Israeli counterstrikes.
On 4 March, Iran announced that the Strait of Hormuz, a key waterway for the shipping of oil, LNG, and other products, was "closed", and threatened to attack any ship that attempted to pass it. It would eventually make exceptions for ships from countries it deemed to be "friends" of the republic, as with seven stranded Malaysian ships that it allowed to pass through the strait on 6 April. On 9 March, Iran declared that they would bring more security passage to the countries that expels US and Israel ambassadors. By 9 March, shipping insurance rates for the strait were reported to have increased by four to six times over the previous week, and the US government began to offer help to insurers under the Terrorism Risk Insurance Act, while continuing to warn commercial shipping against the area. The same day, Trump said that Iran's military had been destroyed, that the strait was open, and that the US might seize control of it from Iran to keep it open for commercial activity. On 27 March, he reaffirmed his desire to control the strait and also expressed interest in renaming it either to the "Strait of America" or to the "Strait of Trump", later referencing the latter name in a speech.
Iranian blockade
List of ships attacked by Iran
Footnotes:
Iran's methods of restricting traffic in the strait include:
- Attacks from speed boats (500 to 1000+), missiles and drones are the physical way of keeping ships away.
- Iran has laid mines as a hidden threat which could be anywhere.
- Satellite spoofing and GNSS jamming makes navigation harder.
These three methods are easy to deploy and difficult to oppose, and prohibitively increase insurance cost, preventing most shipowners from sailing through.
Timeline
Within hours of the US and Israeli strikes on 28 February, the IRGC transmitted warnings via VHF radio to vessels in the strait, stating that no ships would be permitted to pass. Iran did not formally declare a blockade, but military and industry sources warned that safety could not be guaranteed, and several ships stayed in port or turned back. The threats led to a partial closure, with ship-tracking data first showing a 70% reduction in traffic.
March
On 1 March, the oil tanker Skylight was struck by a projectile north of Khasab, Oman, killing two Indian crew members and injuring three others. The rest of its 20 crew evacuated. It was sanctioned by the US Department of Treasury for links to the Iranian shadow fleet. The MKD VYOM was struck by a drone boat, sparking a fire and an explosion in its engine room. An Indian sailor was killed, and its 21 crew evacuated on the Panama-flagged MV SAND. Another Indian was critically wounded on the LCT Ayeh.
On 2 March 2026, a senior official in the IRGC officially confirmed that Iran had closed the strait, threatening any ship that attempted to pass the strait. The US-flagged Stena Imperative was struck twice at the port of Bahrain, causing a fire. A port worker was killed and two others hurt in the attack, though the ship's crew were unharmed. The Athe Nova, which has links to Iran, was struck by two drones after attempting to illegally cross, according to the IRGC-linked Tasnim News Agency.
Just after midnight on 2 March, no tankers in the strait broadcast automatic identification system signals, indicating low or no traffic, though with unreliable data and satellite navigation device basis. Protection and indemnity insurance, which is critical for shipping, was removed from 5 March, making the economic risk too high for ship owners to use the strait. It was declared a high-risk zone, requiring extra pay and the right of refusal for ships' crew. The strait remained legally open, but effectively closed.
On 4 March, the IRGC claimed that they had achieved complete control of the strait. By then, at least eight vessels had been damaged. A Malta-flagged ship, Safeen Prestige, was struck, forcing its crew to evacuate. Meanwhile, the Pola, which had earlier turned its AIS transponder off, managed to pass through the strait and deliver its cargo to the UAE, despite the blockade. Late at night, a large explosion caused by a sea drone struck the oil tanker Sonangol Namibe anchored near Mubarak Al Kabeer Port in Kuwait, more than 800 kilometres (500 mi) from the strait, representing a significant expansion of the conflict. The attack caused an oil spill that posed an environmental risk. A small vessel was observed leaving the scene following the attack. The IRGC said that it hit a US oil tanker. On 6 March, a tugboat dispatched to assist the Safeen Prestige was struck by two missiles and later sank, leaving at least three crew members missing. On 7 March, the IRGC claimed that it hit the oil tanker Prima with a drone in the Persian Gulf, and the US oil tanker Louis P with a drone in the strait.
On 10 March, a bulk carrier reported a nearby splash followed by an explosion 36 nautical miles (67 km; 41 mi) off Abu Dhabi, in the first reported maritime incident in days. Also that day, US military intelligence sources reported that Iran had begun planting naval mines in the Strait of Hormuz. Following the reports, US president Donald Trump demanded that Iran should immediately remove any mines it had planted, and the US military said it destroyed 16 Iranian minelayers. A large wave of attacks on ships was carried out on 11 March, with at least three vessels sustaining damage. Twenty crew members of the Thailand-flagged Mayuree Naree were rescued by the Royal Navy of Oman after the vessel caught fire, while three others were missing and later confirmed dead. An unverified attack was also claimed by the IRGC on the Express Rome. Later that day, two oil tankers were attacked by an Iranian drone boat off the Port of Basra, Iraq, setting them on fire and killing at least one crew member. The State Company for Iraqi Ports rescued 38 crew members aboard both vessels.
By 12 March, the UKMTO had received reports of 16 attacks on shipping and four 'suspicious incidents' in the Persian Gulf since the start of hostilities. On 17 March, Kuwait-flagged liquified petroleum tanker Gas Al Ahmadiah was hit by a projectile while anchored east of Fujairah, causing minor damage. The following day, Palau-flagged chemical tanker Parimal was struck east of Khor Fakkan, sparking a fire. Fifteen of its crew were evacuated onto a Cook Islands-flagged tanker, although the captain was reported missing. On 19 March, Qatar-flagged offshore vessel Halul 69 was hit by debris off Ras Laffan Industrial City, damaging the bridge window. On 21 March, a projectile exploded in the vicinity of an unidentified bulk carrier 15 nautical miles (28 km; 17 mi) north of Sharjah, although no injuries were reported.
On 26 March, Israeli defense minister Israel Katz said that Iranian navy commander Alireza Tangsiri was killed in an airstrike, accusing him of being directly responsible for the Strait of Hormuz closure.
On 27 March, Mayuree Naree went aground on Qeshm Island. The IRGC Navy also turned away three container ships from passing through the strait. The IRGC announced that movement through the strait for any vessel going "to and from" the ports of the US, Israel, and their allies is prohibited. On 30 March, the Liberia-flagged container ship Express Rome reported that two projectiles splashed in the water nearby the ship within one hour, 22 nautical miles (41 km; 25 mi) northeast of Ras Tanura, Saudi Arabia. No injuries or damage were reported. Early on 31 March, Kuwaiti very large crude carrier (VLCC) Al Salmi was struck by an Iranian drone while anchored at the Port of Dubai, causing a fire. The vessel was at full capacity at the time, and the Kuwait Petroleum Corporation warned of an oil spill. The fire was later contained, and no oil leak was reported.
April
On 1 April, the QatarEnergy oil tanker Aqua 1 was struck by two projectiles north of Doha, causing a fire that was extinguished. The IRGC claimed that the tanker was Israeli. On 4 April, the IRGC claimed that it attacked the MSC Ishyka with a drone in the Strait of Hormuz, claiming it was linked to Israel. The attack was not verified.
After the Strait of Hormuz reopened on April 17, ships headed toward the strait; however, only 13 tankers passed through, according to Starboard Marine Intelligence.
On 18 April, Iran said that it closed the strait after threatening to do so in response to the US blockade. Two India-flagged ships were targeted by gunfire in the strait and forced to turn back, with the VLCC Sanmar Herald coming under fire from two Iranian gunboats despite having received clearance to pass. Later, a container ship reported damage from a rocket attack off the coast of Oman; no fires or injuries were caused. The vessel was later identified by French company CMA CGM as the CMA CGM Everglade. The cruise ship Mein Schiff 4 reported a nearby splash while off Oman. The master said that the IRGC threatened to fire at and destroy the ship via VHF radio.