Why the Strait of Hormuz moves the price of oil

On Friday Brent crude briefly passed $117 a barrel, its highest since April, after Tehran threatened to retaliate against Gulf refineries if it is attacked again. Near the strait, Iran's Revolutionary Guards said seven tankers were hit or struck mines during the week, and oil from one of them has washed up on beaches in the United Arab Emirates. Oil prices · The spill · The story so far

A narrow door for a lot of oil

The Strait of Hormuz links the Persian Gulf to the Gulf of Oman and the open ocean. At its narrowest it is about 21 miles (33 km) wide, and the shipping lanes inside it are narrower still.

According to the US Energy Information Administration, about 20 million barrels of oil a day moved through the strait in 2024, roughly one-fifth of all the oil the world uses. Much of the world's liquefied natural gas trade passes through it too, mostly from Qatar.

Why prices react so quickly

There are few ways around it. Saudi Arabia and the United Arab Emirates have pipelines that bypass the strait, but they can carry only part of what normally sails through. When ships are attacked, or insurers raise the cost of sailing there, traders price in the risk that supply could be cut, even before any oil actually stops flowing.

What to watch

• Whether shipping through the strait slows, and what insurers charge for the trip
• How major oil importers in Asia respond
• Prices at the pump, which usually follow crude with a delay of a few weeks
• The attacks themselves, day by day: the story so far

See today's energy stories on the globe.