What this system is
Around 20 million barrels a day of crude oil and petroleum products moved through the Strait of Hormuz in the 2025 baseline — roughly a third of global crude oil trade. Every core state except Oman loads into an enclosed sea whose only outlet is that strait.
A constraint at one point reaches five producing states simultaneously, because they share an outlet rather than a route. That is what makes this a system rather than a set of national export chains, and it is why the module treats maritime access as the organising question of Gulf security rather than as one file among several.
Confidence: High As of 2026-10-06Reviewed 2026-10-04
The system
- Overview
- This is the region's principal export system and the reason the Iran–Gulf module exists. Saudi Arabia, Iran, the UAE, Kuwait and Bahrain all hold their main loading terminals inside the Gulf, an enclosed sea with a single outlet to the ocean. In the 2025 baseline the Congressional Research Service recorded approximately 20 million barrels a day of crude and petroleum products moving through the Strait of Hormuz, being roughly 34% of global crude oil trade and about 20% of world petroleum liquids consumption. Oman is the exception: its principal terminals face the Gulf of Oman and it does not appear in official estimates of closure-related shut-ins. The nodes below are the points at which this system meets the water. Their order is the record's own grouping and is not a sequence of movement.
- What depends on it
- Near-total for Qatar, Kuwait, Bahrain and Iraq, which have no alternative outlet at all. Partial for Saudi Arabia and the UAE, each of which can divert a fraction of normal volumes through a pipeline to a coast outside the strait. Absent for Oman alone. Iran's dependence is as high as its neighbours': its own exports leave through the same water it is able to constrain.
- What disruption does
- Production that cannot reach a buyer is shut in rather than stored, which is why the effect appears as removed supply rather than as accumulating inventory at the terminals. The shut-in series above is the measure of that, and it grew for four months before easing — a disruption that deepened as it persisted rather than one absorbed by adjustment.
- Alternatives and redundancy
- Two fixed alternatives exist and one does not. Saudi Arabia can route crude west to the Red Sea and the UAE can route crude to the Gulf of Oman; together with the minor Iraqi line to Türkiye and Iran's barely used Jask route, all alternatives combined have been assessed at roughly 3.5 to 5.5 million barrels a day against normal Hormuz volumes of about 20 million — between a sixth and a quarter. For liquefied natural gas there is no bypass of any size. Nothing in this system substitutes for the strait; the alternatives reduce exposure at the margin and change who is exposed, not whether the region is.
Nodes
In the order this record authors them — an authored sequence, not a route.
Saudi Arabia's principal crude export terminal and refinery complex on the Gulf coast, and the largest single loading point in the Hormuz-dependent export system.
In this systemSaudi Arabia's principal crude loading point and the largest in the system.
Why it mattersIt is where the largest producer in the system meets the water. Drones were intercepted over the refinery on 2 March 2026; a fire started from debris and the facility halted operations, reopening on 13 March. Saudi Arabia attributed the attack to Iran and Iranian officials denied targeting Gulf energy facilities.
What to watchLoading continuity, and whether the attribution of the March 2026 attack is ever independently established.
Port Confidence: High As of 2026-09 Show on the map →
Iran's principal crude export terminal, in the northern Gulf. Reported as handling up to around ninety per cent of Iranian crude exports.
In this systemReported as handling up to around 90% of Iranian crude exports.
Why it mattersIran's own export concentration is as extreme as any in the region and its position is the same as its neighbours': inside the Gulf, upstream of the strait. Closing the Strait of Hormuz constrains Iranian exports too, which is the fact most often missing from accounts that treat the strait as an Iranian lever without a cost.
What to watchLoading continuity, and the share of Iranian exports moving through this terminal versus any alternative.
Port Confidence: Moderate As of 2026-09 Show on the map →
The principal Emirati refining and petrochemical complex on the Gulf coast, west of Abu Dhabi.
In this systemEmirati refining and product output facing the Gulf rather than the Fujairah route.
Why it mattersIt is the UAE's main refined-product output and a Gulf-facing node, so unlike the Fujairah route it remains inside the Hormuz-dependent system. It shows that a state with a bypass is not thereby outside the chokepoint: only the volumes actually routed through the bypass are.
What to watchWhether product exports continue to move through Gulf loadings or shift where the pipeline allows.
Refinery Confidence: Moderate As of 2026-09 Show on the map →
Kuwait's principal crude export terminal on the northern Gulf coast.
In this systemKuwait's principal terminal; no alternative outlet exists.
Why it mattersKuwait has no route to market that avoids the Strait of Hormuz, and its exports were described as effectively halted during the closure. Its position at the head of the Gulf makes it the most enclosed of the major exporters — furthest from the strait and with no alternative coastline at all.
What to watchResumption and continuity of loadings.
Port Confidence: Moderate As of 2026-09 Show on the map →
Bahrain's refinery and export terminal, the smallest of the Gulf's national export outlets.
In this systemBahrain's terminal; the smallest national outlet in the system and equally dependent.
Why it mattersBahrain is the smallest producer in the system and, like Kuwait and Qatar, has no Hormuz alternative. Its exports were described as effectively halted during the closure. It demonstrates that exposure in this system is not proportional to size — the smallest producer is as completely dependent as the largest.
What to watchResumption and continuity of loadings.
Port Confidence: Moderate As of 2026-09 Show on the map →
Oman's principal crude export terminal, on the Gulf of Oman coast outside the Strait of Hormuz.
In this systemOman's principal terminal, and the one node in this list that sits OUTSIDE the strait. Included to show the exception rather than to imply Omani dependence on it.
Why it mattersThis marker is the Omani exception made concrete. Because Oman's export terminals face the open ocean rather than the enclosed Gulf, Omani production does not appear in official estimates of Hormuz closure-related shut-ins — the only Gulf Arab producer of which that is true, and a large part of why Oman can hold the position it does in the region's diplomacy.
What to watchWhether loadings continue undisturbed while Gulf-facing terminals do not.
Port Confidence: Moderate As of 2026-09 Show on the map →
The waterway connecting the Gulf to the Gulf of Oman and the open ocean, comprising Iranian and Omani territorial waters. Around 20 million barrels a day of crude oil and petroleum products moved through it in the 2025 baseline, with close to a fifth of world LNG exports.
In this systemThe single outlet. Its usable state is set by legal, physical and commercial conditions that moved independently in 2026.
Why it mattersEvery Gulf Arab producer except Oman must pass this water to reach a customer, and so must Iran. It is the single point on which the region's export economy, and a material share of the world's, converges. The alternatives to it carry between a sixth and a quarter of what it normally moves, and for LNG they carry nothing.
What to watchWhether commercial transit resumes at scale, and on what insurance terms — the strait's usable state has been set by commercial risk rather than by physical blockade.
Sea area / strait · broad context Confidence: High As of 2026-09 Show on the map →
The Omani port and industrial complex on the Gulf of Oman, outside the Strait of Hormuz, and the water off it where Saudi crude is transferred between vessels.
In this systemAdded 20 September 2026. The water off the Omani port where Saudi crude loaded at Ras Tanura is transferred between vessels after running the strait on short escorted legs — the seaward end of a route that begins inside the chokepoint rather than avoiding it.
Why it mattersCreated on 20 September 2026 because the module's own records had been naming it as an absence. The energy-strike series listed Sohar among the nodes it could not count for want of a marker, and the September rerouting made the omission untenable: about sixty million barrels of Saudi crude were sold for September and October loading by ship-to-ship transfer in the waters off this port, after short escorted runs out of the Gulf. That makes Sohar the seaward end of a route that begins inside the strait rather than avoiding it — the opposite of what the east–west pipeline was built to do, and the reason the marker exists.
What to watchWhether the ship-to-ship arrangement persists once the east–west pipeline returns to capacity, and whether any incident is reported at the port or in the transfer area.
Port Confidence: Moderate As of 2026-09 Show on the map →
Iran declared the strait closed to normal commercial traffic on 28 February 2026 and cross-strait traffic largely halted. The United States Energy Information Administration described the strait as effectively closed to shipping and built its outlook on that assumption. Transit resumed briefly under a memorandum of understanding from mid-June before commercial access degraded again from early July.
Production shut-ins attributed to the closure, as a dated series rather than a single figure: an estimated 7.53 million b/d in March 2026, a forecast peak of 9.10 million in April, 11.3 million in May and a forecast 11.34 million in June, easing to a forecast 10.11 million in the third quarter and 5.70 million in the fourth. These measure production made unavailable, not exports and not capacity.
With the east–west pipeline shut from 10 September, Saudi crude was loaded inside the Gulf and run through the strait on short escorted legs for ship-to-ship transfer off Sohar — state cargo, not a return of commercial traffic. Trade-data figures, each with its own vintage and each a tracker's estimate rather than a published operator series: Rystad Energy put Hormuz-route exports above two million barrels a day in the first two weeks of September; Kpler data reported by Baird Maritime put Saudi Hormuz-route exports at about 42 million barrels in the week of 13 September; Kpler cargo data reported by DataPortuaria showed six very large crude carriers loading nearly 12 million barrels at Ras Tanura and Juaymah on 21 September. Tracked commodity-vessel transits through the strait were 17 on the weekend of 19–20 September against 37 the weekend before (Kpler and LSEG), against a pre-war norm of about 125 large vessels a day; trackers note that tankers transiting with transponders off are not counted. The pipeline was reported restarted at a low rate on 22 September.
Kpler put September crude exports from the Gulf, excluding Iran, at no less than 16.5 million barrels a day, the pre-war average, by a changed route. About 60 per cent (9.9 million) physically crossed the strait, mostly on shuttle tankers; 23 per cent loaded on the Gulf of Oman coast, mainly at Fujairah; 17 per cent left through the Red Sea. Before the war 83 per cent crossed the strait. In August more than 70 per cent of the crude crossing the strait changed tankers off Fujairah or Sohar. Kpler states its recent figures are minimum confirmed volumes, recorded even when one tanker in a transfer is dark. Iranian exports remained blocked. On 1 October the Joint Maritime Information Center recorded 113 United States-facilitated transits in the four days to 30 September, while independent tracking of other cargo vessels above 1,000 dwt showed single-digit transits each way. It gave a 2025 baseline of about 138 vessels a day, on its own definition, which differs from the pre-war norm of about 125 large vessels a day carried above. Six tankers were struck in the strait between 28 September and 2 October.
Tracker data, each figure with its own definition. In a note dated 6 October, Kpler put crude crossing the strait in the latest week at no less than 10.1 million barrels a day, down 27 per cent from the war-time high of the week before, about 74 per cent of the pre-war level and level with the September average; most of the fall came from ship-to-ship transfers in the Gulf of Oman. Exports from the Gulf of Oman coast and the Red Sea rose to 6.7 million barrels a day, more than double the pre-war level. Kpler counted seven commodity vessels through the strait on 6 October, the fewest since 23 July, and ten on 7 October, against more than twenty on 4 and 5 October; LSEG counted eight on 6 October against fourteen the day before. Neither count includes vessels transiting with transponders off. The fall followed the most strikes on tankers in the strait of any week of the war.
Economic implications
Removed Gulf supply raised demand for barrels from elsewhere and drew down global inventories; the market consequences are carried in the module's impact chains and in Weekly Briefs, not as figures on this record.
Humanitarian implications
Seafarers aboard vessels unable to move became the direct human cost of the access constraint, and are covered in the module's humanitarian chain.
Actors with a stake
Campaign relevance
What remains unknown
- Current transit volumes at a weekly grain are not established by Vigil. The module publishes the 2025 baseline and the dated disruption series, and does not estimate present flow; the September 2026 figures above are trackers' counts carried with their vintages and attributions, they differ between trackers by definition of transit and cargo, and dark transits are outside them.
- The shut-in series is produced by one agency on a monthly forecast cycle. Later vintages revised earlier months substantially, and the figures are carried with their vintage for that reason.
- MINE PRESENCE IN THE STRAIT IS REPORTED AND NOT INDEPENDENTLY ESTABLISHED. The International Maritime Organization’s position that there is no safe transit anywhere in the strait is the authoritative navigational statement this module carries, and it is a statement about conditions rather than about causes. Mine clearance appeared among the commitments reported in the June 2026 memorandum, which is evidence that the parties treated a hazard as real; it is not a survey. Who laid what, where, and how much of it remains are all unknown here, and would stay unpublished even if they were known: this module authors no coordinates, no lane locations, no suspected boundaries, no densities and no clearance routes, because that is operational geography rather than evidence.
Readings the evidence also supports
- Part of the shut-in total may reflect demand destruction and voluntary restraint rather than an inability to route cargo. The source attributes the series to the closure; Vigil records that attribution rather than independently establishing the cause of each barrel.
Listed because the record's own assessment is not the only one its sources permit — not as a hedge on the assessment above.
Watch questions this system bears on
Standing analytical questions whose evidence runs through this system, each with its latest review. Derived from the Watch object, never restated here.
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Assessed as of — 2026-10-06 Last reviewed — 2026-10-04 Changed in brief — 2026-10-11 · Economy updated