When Hormuz Tightens, Why Does East Asia Feel It First?

Where is the Strait of Hormuz, and how narrow is it?

The strait sits at the southeastern end of the Persian Gulf, with Iran on the northern shore and Oman’s Musandam exclave on the southern one. It connects the Gulf to the Gulf of Oman and onward to the Arabian Sea and the Indian Ocean.

At its narrowest the strait is about 39 kilometres wide, and the lanes that large tankers actually use are far narrower: about 3.7 kilometres in each direction. Everything that follows starts from that scale. Hormuz is less a sea than a corridor.

Which country does the Strait of Hormuz belong to?

No single country, though no part of it is high seas either. Iran and Oman each claim a 12-nautical-mile (about 22 km) territorial sea, and the strait is only about 39 km wide at its narrowest, so the two territorial seas meet in the middle and the whole passage lies within them. The shipping lanes mentioned above, in place since 1968, lie in Omani waters.

Lying within territorial seas does not give the coastal states the right to close the strait. Under the UN Convention on the Law of the Sea, straits used for international navigation are subject to “transit passage”: ships and aircraft may pass continuously and expeditiously, and coastal states may not impede or suspend that passage. Oman has ratified the convention; Iran signed but never ratified it, and argues that transit passage is a treaty bargain among the parties rather than a right everyone can claim.

In peacetime, then, “who owns it” sounds like a legal detail; in a crisis it becomes “who decides who passes”. In late June 2026, Iran told Oman that the existing traffic separation scheme had to change. The blockade question discussed below starts from this legal gap.

How much oil passes through each day?

In 2025 close to 15 million barrels a day of crude and condensate passed through the strait, plus nearly 5 million barrels a day of refined products. The oil came from Saudi Arabia, Iraq, Kuwait, Qatar, the UAE, and Iran, and most of it went to Asia.

Liquefied natural gas (LNG) depends on the strait even more heavily. In 2025 roughly 93% of Qatari LNG and 96% of Emirati LNG had to transit Hormuz, together about 19% of global LNG trade, and nearly 90% of it was bound for Asia.

So when this corridor narrows, the first to feel it are not Middle Eastern producers but refineries, power plants, and factories in East Asia.

Can Iran actually “close” the strait?

Fully closing it would be extremely costly and would damage Iran’s own exports, so it is rarely a realistic option. The war that broke out between Iran and the United States and Israel at the end of February 2026 was no exception: after Iran’s Revolutionary Guards declared the strait closed in early March, most traffic stopped, yet Iranian tankers kept sailing and ships linked to India, Pakistan and a handful of other countries were allowed through. But that is the wrong question to ask.

Iran does not need to close the strait to exert pressure. Inspections, routing restrictions, transit charges, and ad hoc security demands are enough to raise the risk of passage, and shipowners, insurers, and buyers respond by raising prices or delaying sailings. What oil markets fear most is not any single incident but the next one, which no one can predict.

That pulls Hormuz away from being a public waterway and toward a conditionally open political corridor: vessels on good terms with Tehran may be treated more leniently, while others absorb higher costs. This is what grey-zone tactics look like at sea.

Is there a way around it?

Yes, but only two, and they carry only crude.

Saudi Arabia’s East–West pipeline runs from Abqaiq across the peninsula to Yanbu on the Red Sea. It peaked at 7 million barrels a day in the first quarter of 2026, but loadings at Yanbu in mid-July 2026 were closer to 4.7 million. Nameplate capacity is what the engineering documents say; how much actually gets shipped depends on tank farms, berths, and vessel scheduling working as a system.

The UAE’s Abu Dhabi Crude Oil Pipeline (ADCOP) runs from Habshan to Fujairah on the Gulf of Oman, outside the strait, and carries about 1.8 million barrels a day. A new line due in 2027 is set to double that bypass capacity.

Together the two lines can move about 6.5 million barrels a day around the strait, against roughly 20 million passing through it. And they move only crude: refined products and LNG have no overland fallback, and Kuwait, Qatar, and Bahrain have no pipeline at all.

What does this mean for Taiwan?

Taiwan imports nearly all its energy, a substantial share of it from the Gulf by way of Hormuz, the Strait of Malacca, and the South China Sea. Risk at the strait does not stay in the Middle East; it travels along that sea lane and shows up in Taiwan’s electricity prices, consumer prices, and industrial costs.

More importantly, Hormuz illustrates a broader pattern: when a country’s critical supplies have only one route, whoever guards that route gains asymmetric bargaining power. The logic is not confined to oil; semiconductor equipment, critical minerals, and submarine cables each have their own Hormuz. Understanding how a chokepoint works is therefore far more useful than memorising where the strait is.