Level 1 — Absolute Beginner
The Strait of Hormuz is a narrow sea passage. Many ships carry oil through it every day. It is next to Iran.
There is a conflict there. Iran attacks some ships. But the oil still moves.
Today about 10.3 million barrels of oil pass through each day. In the spring, only 2.72 million barrels passed each day. So the number is much higher now.
American warships help the oil ships. Iran cannot sell its own oil now. It sells zero barrels.
- strait
- a narrow area of sea between two pieces of land
- narrow
- not wide
- oil
- a thick liquid from under the ground used for fuel
- barrel
- a large container; also a unit for measuring oil
- conflict
- a serious fight or disagreement
- attack
- to try to hurt or damage someone or something
- warship
- a ship built for fighting
- zero
- none; the number 0
Level 2 — Elementary
The Strait of Hormuz is one of the most important shipping routes in the world. A large share of the oil used by other countries travels through this narrow channel beside Iran. Since the spring of 2026 it has also been a conflict zone.
The numbers tell a surprising story. Before the fighting began, about 16.63 million barrels of crude oil left the Gulf through the strait every day. During the first American blockade, between April and June, that fell to only 2.72 million barrels.
Now the flow has recovered. Tanker tracking specialists put the figure at roughly 10.3 million barrels a day, and Samir Madani, who founded the tracking service TankerTrackers, says this is happening while Iranian forces continue to attack vessels.
Admiral Brad Cooper, the head of United States Central Command, said in a video message on 19 September that allies in the Gulf had shipped more than a billion barrels through the strait in recent months, protected by American ships and mine clearing teams. He also noted that Iran itself has exported zero barrels under the blockade.
- shipping route
- a path that ships regularly follow
- channel
- a narrow stretch of water joining two larger areas
- conflict zone
- an area where fighting is taking place
- crude oil
- oil in its natural state, before it is refined
- blockade
- an action to stop ships entering or leaving an area
- recover
- to return to an earlier and better level
- vessel
- a ship or large boat
- mine clearing
- removing explosive devices from the sea
Level 3 — Intermediate
One of the more counterintuitive features of the conflict around the Strait of Hormuz is that the oil has largely kept moving. Tanker tracking data compiled by TankerTrackers divides the year into distinct eras, and the contrast between them is stark: 16.63 million barrels a day before the fighting began, 3.45 million during the opening phase, and just 2.72 million while the first American blockade was in force between April and June.
The recovery since then has been steep. A short window in which a memorandum of understanding held saw flows return to about 10 million barrels a day, and although a second blockade period brought the average back to 4.9 million, the most recent readings put the figure at roughly 10.3 million. Samir Madani, who founded the tracking service, notes that these volumes are moving while Iranian forces are still striking commercial shipping.
Across 186 days of conflict the cumulative total came to 779 million barrels, an average of 4.19 million a day. That average conceals the volatility beneath it, which is the practical problem for refiners and for governments trying to judge whether a cargo will arrive on schedule.
American officials present the recovery as a result of naval escorting. Admiral Brad Cooper of United States Central Command said allies in the Gulf had moved more than a billion barrels through the waterway in recent months while Iran exported nothing at all, and the Energy Secretary, Chris Wright, told reporters on 13 September that markets would keep depending on roughly 10 million barrels a day through the strait, describing conditions as tighter than he would like but not overly tight.
- counterintuitive
- the opposite of what you would naturally expect
- era
- a distinct period of time with its own character
- stark
- very clear and often severe
- memorandum of understanding
- a written agreement that is not a full treaty
- cumulative
- added up over a period of time
- volatility
- a tendency to change quickly and unpredictably
- refiner
- a company that turns crude oil into usable fuels
- escort
- to travel alongside something in order to protect it
Level 4 — Advanced
The received wisdom about the Strait of Hormuz has always been that interference there translates directly into a supply shock, and 2026 has complicated that assumption without quite refuting it. The tracking series maintained by TankerTrackers reads as a sequence of regimes rather than a trend: 16.63 million barrels a day through the pre-conflict months, 3.45 million once hostilities opened, 2.72 million under the first American blockade from mid April to mid June, roughly 10 million during the brief period when a memorandum of understanding held, and 4.9 million through the second blockade phase. The latest readings, at approximately 10.3 million barrels a day, sit at the upper end of that range while Iranian attacks on commercial shipping continue.
The aggregate is instructive precisely because it flatters the period. Some 779 million barrels transited across 186 days of conflict, an average of 4.19 million a day, a figure that would have been read as catastrophic in advance and now looks like the floor beneath a recovering flow. Averages of this kind are poor guides to operational reality: a refiner does not consume a mean, it consumes cargoes that either berth on schedule or do not, and the insurance and chartering markets price the variance rather than the average.
Two mechanisms account for the resilience. The first is military, in the form of escorting and mine countermeasures, which Admiral Brad Cooper of United States Central Command credits with enabling Gulf producers to move more than a billion barrels in recent months. The second is commercial: freight rates have risen enough that owners are compensated for accepting a war risk they would otherwise decline, which is how a dangerous route continues to clear.
The asymmetry at the heart of the picture is that Iran has exported nothing while its neighbours ship at close to normal volumes, a reversal of the leverage the strait was long assumed to confer. Chris Wright, the Energy Secretary, framed the outlook on 13 September in terms of continued dependence on roughly 10 million barrels a day through the waterway, calling markets tighter than he would like without conceding real scarcity. That formulation is careful for good reason: the recovery rests on a naval commitment and a risk premium, and neither is a structural feature of the route.
- received wisdom
- an idea widely accepted without much questioning
- refute
- to prove that something is wrong
- regime
- here, a distinct pattern or state that a system settles into
- flatter
- to make something look better than it really is
- berth
- to bring a ship into its place at a dock
- variance
- the amount by which values differ from the average
- countermeasure
- an action taken to neutralise a threat
- leverage