Two supertankers can barely pass each other in the Strait of Hormuz. The shipping lanes are only about 2 miles wide: one inbound, one outbound, with a 2-mile buffer between them. Roughly 20 to 21 million barrels of crude oil and petroleum products squeeze through every day, around 20% of global petroleum consumption.
That is the whole problem in a sentence, and in 2026 it stopped being theoretical.
Geography of a bottleneck
The strait sits at the mouth of the Persian Gulf and links it to the Gulf of Oman and the Arabian Sea. It runs about 104 miles in length and varies from roughly 35 to 60 miles across. Iran lies to the north. To the south is Oman’s Musandam Peninsula, which is cut off from the Omani mainland. Three islands, Qeshm, Hormuz and Larak, are under Iranian jurisdiction, and the Iranian port of Bandar Abbas on the northern shore is among the region’s busiest.
No comparable route exists for supertankers leaving Gulf terminals. Qatar, the world’s largest LNG exporter, ships virtually all of its output through the same corridor. China, Japan, South Korea and India, the largest oil importers, depend on it most.
An old prize
Merchants hauled spices, textiles and precious metals through these waters long before oil. The island of Hormuz was once a medieval trading kingdom wealthy enough that the Portuguese navigator Afonso de Albuquerque seized it in 1507, and Portugal dominated the strait for over a century afterward. In the later Iran-Iraq War, the “Tanker War” phase saw hundreds of merchant vessels attacked, and the US Navy escorted Kuwaiti tankers under Operation Earnest Will.
The legal picture is murky. The strait lies in the territorial waters of both Iran and Oman, so ships must pass through one country’s waters or the other’s. The UN Convention on the Law of the Sea guarantees “transit passage” through international straits, but Iran is one of the few major maritime nations that has not ratified it and so does not formally recognize the right. Oman has kept a more neutral posture and has served as a back channel between Iran and Western nations.
The 2026 closure
Armed conflict broke out between the United States, Israel and Iran. Iran shut the strait to foreign shipping, the IRGC warned vessels off, attacked merchant ships and laid sea mines. By early March 2026 the strait had effectively closed. Tanker traffic fell by 90%. Oil prices went past $120 per barrel, the sharpest monthly rise ever recorded, and QatarEnergy halted all LNG exports. Gulf producers cut output as their storage filled.
The damage reached plastics, fertilizers, pharmaceuticals and electronics within weeks. War-risk insurance made transit unworkable for most shipping companies. Gulf states lost an estimated $1.1 billion per day in oil revenues.
As of June 8, 2026, the strait had been effectively closed for 94 days, the longest uninterrupted disruption on record for the chokepoint. Diplomacy stalled. A UN Security Council resolution calling for reopening was vetoed in early April. Tehran declared the passage open on April 17, and the IRGC reversed that within 24 hours. A fragile ceasefire held, yet almost no commercial ships moved through.
Saudi Arabia and the UAE have bypass pipelines, but their combined capacity covers only a fraction of normal throughput. Iraq, Kuwait, Qatar and Iran have no bypass at all. Governments across Europe and Asia have begun diversifying supply and speeding up energy transition spending.
