The Strait of Hormuz, the 33-kilometer chokepoint through which roughly a quarter of the world's seaborne oil trade and a fifth of its liquefied natural gas normally passes, has been effectively closed to commercial shipping in waves since 28 February 2026, when the United States and Israel opened Operation Epic Fury, an air campaign against Iran that began the wider 2026 Iran War.¹ In retaliation, the Islamic Revolutionary Guard Corps Navy (IRGC Navy) declared the strait closed, boarded and struck merchant vessels, and laid sea mines along the shipping lanes. The International Energy Agency has called the resulting disruption the largest supply shock in the history of the global oil market.² As of mid-July 2026, after two failed ceasefire attempts and a brief reopening, the strait remains dangerous and largely avoided by large tankers, with fighting between Washington and Tehran resuming days before this article was written.

The crisis is distinct from, but closely tied to, two narrower events covered separately in this archive. The 2026 Strait of Hormuz campaign refers specifically to the US aerial operation launched on 19 March 2026 to suppress Iranian fast-attack boats, drones and minelayers around the strait, while the 2026 United States naval blockade of Iran refers to Washington's own blockade of Iranian ports, imposed on 13 April and reinstated on 14 July. This article covers the broader crisis, the closure itself, the mining and ship attacks, and the economic shockwaves that followed.

The immediate trigger was the war's opening strikes. Before dawn on 28 February, US and Israeli aircraft and missiles hit Iranian nuclear and military sites in a campaign that included the assassination of Ali Khamenei, and Iran answered with missile barrages against Israeli cities and US bases across the Gulf.¹ Tension had been building for months beforehand, rooted in failed nuclear talks in Geneva and a shorter, twelve-day air war between Israel and Iran in 2025 that left the underlying dispute unresolved.

Closing or threatening to close Hormuz had been a standing feature of Iranian deterrence doctrine for decades, but this was the first time Tehran actually executed it at scale. A senior IRGC official confirmed on 2 March that the strait was closed to shipping, and by 4 March the IRGC Navy claimed full operational control of the waterway.³ Iranian officials framed the closure as retaliation for the strikes on Khamenei and Iranian territory, and as leverage against a US military it could not confront symmetrically. Iran later refined the closure into a selective system, announcing on 27 March that the strait was closed only to vessels bound to or from the United States, Israel and their allies, while China, Russia, India, Iraq and Pakistan (named as "friend" nations) could continue to transit.¹ On 5 May, Iran formalized this into the Persian Gulf Strait Authority, a body meant to require ships to seek Iranian clearance and follow routes hugging the Iranian coast, effectively asserting a toll system over a waterway long treated as an international strait.⁴

Ship attacks began within days of the war's opening. On 1 March, the tanker Skylight was struck and abandoned, killing two Indian crew members, and the MKD Vyom caught fire after a drone-boat strike that killed another sailor.¹ The IRGC Navy confirmed the closure on 2 March, and by 4 March claimed full control of the strait, the same day a tugboat assisting the Safeen Prestige sank after a missile strike, leaving crew members missing.

That same day, the sinking of IRIS Dena, a Moudge-class frigate returning from an international naval review off Sri Lanka, became one of the war's starkest naval losses when the US Los Angeles-class submarine USS Charlotte torpedoed it in international waters, killing 104 of its 136 crew.⁷

Insurers pulled protection and indemnity cover for Hormuz transits from 5 March, and by 9 March war-risk premiums had risen four to six times over the previous week alone, from a pre-war range of roughly 0.15 to 0.25 percent of hull value per week to as much as five to ten percent.⁸ Brent crude passed $100 a barrel on 8 March for the first time in four years and kept climbing. On 10 March, US intelligence reported Iran had begun laying naval mines a second time, and the US military said it had destroyed sixteen Iranian minelaying boats.⁹

The 2026 Strait of Hormuz campaign opened on 19 March, with the US deploying A-10 Thunderbolt II attack aircraft against Iranian fast boats and AH-64 Apache gunships against one-way attack drones threatening shipping lanes.¹⁰

Israel killed Tangsiri on 26 March, and the next day Iran announced its selective closure exempting the five "friend" nations. A brief ceasefire, agreed around 8 April, collapsed when follow-up talks in Islamabad failed, and Trump declared a formal US naval blockade of Iranian ports effective 13 April, producing what analysts called a "dual blockade" in which Iran and the United States each restricted the other's access to the same waterway.¹ Iran responded by re-closing the strait on 18 April and stepping up ship seizures, taking the container ships MSC Epaminondas and MSC Francesca on 22 April. By 21 April, roughly 20,000 mariners and 2,000 ships were stranded in and around the Gulf, a figure that Chairman of the Joint Chiefs General Dan Caine updated on 6 May to 22,500 mariners trapped aboard more than 1,550 vessels.¹¹

Iran seized the bulk carrier Ocean Koi on 8 May and the fishery research vessel Hui Chuan on 14 May, accusing them of aiding Iran's adversaries, while the Indian-flagged livestock carrier Haji Ali sank on 13 May after being struck and losing stability.¹ The US naval blockade, run by CENTCOM commander Admiral Brad Cooper with more than 10,000 personnel and over a dozen warships, had intercepted 94 vessels and seized four by 22 May, at an estimated cost to Iran of $4.8 billion in lost oil revenue, before its first phase was lifted on 29 May as diplomacy resumed.¹²

Mediators announced a memorandum of understanding on 14 June, and Trump and Iranian President Masoud Pezeshkian signed the Islamabad Memorandum on 17 June, intended to end the war and both blockades within 60 days. It did not hold. Iran closed the strait again on 20 June, citing what it called Israeli violations of a separate Israel-Hezbollah ceasefire, and a French and British-led minesweeping operation, using underwater drones, mine-hunting helicopters and mechanical sweeps, continued working through late June against mines Iran was required to clear within 30 days of the framework agreement.⁶ Oil prices eased back toward $70 a barrel by 29 June as the market priced in a durable reopening, before fighting resumed.¹³

A US Navy helicopter made an emergency landing in the Arabian Sea on 1 July, with one aviator reported missing, and on 6 to 7 July the LNG tanker Al Rekayat and the supertanker Wedyan were both struck, pushing the strait's threat designation to "severe."¹⁴ Renewed US strikes hit Iranian sites on 8 to 9 July, and Iran retaliated against US-linked positions in Bahrain, Kuwait, Qatar, Jordan and Iraq on 10 July.¹⁵ Shipping traffic collapsed accordingly, from around 130 daily transits before the war to 45 on the Monday before the renewed fighting and just 5 in the days that followed, with no large tanker above 10,000 deadweight tons using the US-coordinated "Southern Highway" route along the Omani coast with tracking systems switched on.¹⁵ On 12 July, the IRGC again declared the strait closed after the Cyprus-flagged GFS Galaxy was struck, though maritime security group JMIC reported the southern route remained physically open to two-way traffic despite Iran's declaration.¹⁶ The US naval blockade of Iranian ports was reinstated on 14 July, the day this article was researched.

Is the Strait of Hormuz closed right now? As of mid-July 2026, the IRGC Navy has again declared the strait closed following the 12 July strike on the tanker GFS Galaxy, though a narrow "Southern Highway" route along the Omani coast has stayed physically open to some traffic despite the declaration.¹⁶

Why did Iran close the Strait of Hormuz? Iran closed the strait in retaliation for the US and Israeli strikes that opened the 2026 Iran War on 28 February, using the threat to shipping as leverage against a US military it could not confront directly, later refining the closure into a selective system that exempted China, Russia, India, Iraq and Pakistan.^1,3

How much oil normally passes through the Strait of Hormuz? Before the crisis, about 25 percent of the world's seaborne oil trade and 20 percent of its liquefied natural gas transited the strait, figures cited by the International Energy Agency in describing the closure as the largest supply disruption in the history of the global oil market.²

What is the difference between the Strait of Hormuz crisis and the Strait of Hormuz campaign? The crisis is the broader closure of the strait and its economic and shipping fallout beginning 28 February 2026, while the Strait of Hormuz campaign refers specifically to the US military operation launched 19 March to suppress Iranian minelayers, fast boats and drones threatening shipping.^1,10

Did the Strait of Hormuz crisis affect global oil prices? Yes. Brent crude passed $100 a barrel on 8 March 2026 for the first time in four years, later peaking above $180 a barrel in late April, before easing toward the $70s by late June as diplomacy briefly progressed, then facing renewed pressure once fighting resumed in July.^2,13