Why the Iran War Created a Refined-Fuel Crisis Even as Crude Supplies Recover

The war that began on February 28 produced an oil shock, but its most persistent effect has been on refined fuels—especially diesel, gasoline and jet fuel. Attacks on Middle Eastern energy infrastructure, reduced tanker traffic through the Strait of Hormuz and damage to Russian refineries cut the system’s ability to turn crude into finished products. 36

That distinction matters. Crude supply and prices can begin to recover when shipping routes reopen, yet fuel prices may remain high if refineries are damaged, exports are restricted or inventories have already been drawn down. The available evidence points to a severe supply shock, but not yet to a settled conclusion that elevated fuel prices will last for years.

How a crude disruption became a fuel shortage

The Strait of Hormuz is a critical route for crude and petroleum products. During the second quarter of 2026, an average of just 4.9 million barrels per day of crude oil and petroleum liquids moved through the strait, compared with 21.6 million barrels per day in the fourth quarter of 2025, before the conflict.

The disruption affected both sides of the refining chain:

• Refineries struggled to receive crude feedstock.
• Finished fuels faced difficulty reaching importing markets.
• Some Middle Eastern facilities were attacked or forced offline.
• Alternative routes could move some supply, but could not immediately replace normal Hormuz volumes.

The IEA described the resulting interruption as the largest supply disruption in the history of the global oil market. Global observed oil inventories fell by 85 million barrels in March, with stocks outside the Middle East Gulf declining by 205 million barrels as flows through Hormuz were choked off.

Refining capacity became the central constraint

The crisis was not simply a shortage of crude in the ground. It was a shortage of operating refineries and dependable logistics.

The IEA estimated that Middle Eastern processing was 2.9 million barrels per day below pre-war levels in the second quarter and would remain 2.2 million barrels per day below those levels in the third quarter. Ukrainian attacks also pushed Russian refining close to a two-decade low; Russian refinery production was reported at 3.9 million barrels per day in July. 12

Taken together, Middle Eastern refinery damage and the loss of Russian capacity removed roughly 5 million barrels per day—about 6% of pre-war global refining output—in the second quarter. Global refinery runs averaged about 78 million barrels per day, the lowest level since the depths of the 2020 COVID-19 pandemic, according to the IEA estimates cited in reporting. 3

That is why the market could experience a refined-product shortage even when crude is available elsewhere. A refinery cannot be replaced by simply redirecting an oil cargo; damaged units, disrupted utilities, unavailable shipping and uncertain operating conditions all limit how quickly output can return.

Why diesel prices moved more sharply than crude

Diesel is particularly exposed because it powers freight, agriculture, construction and much of heavy industry. Europe also entered the shock with limited product buffers: gasoil stocks at the Amsterdam-Rotterdam-Antwerp hub were reported at 24% below their five-year average. 1

Refining margins show how tight the market became. In the euro area, diesel’s refining margin component rose from €0.10 per litre of retail price before the war to €0.35 in the first three weeks of July. The corresponding petrol margin rose from €0.04 in February to €0.23 in July. 4

Prices for finished fuels consequently outpaced the initial move in crude. European diesel prices rose more than 70% from the start of the war, while U.S. gasoline prices increased by around 60%, according to reporting citing IEA data. 5

The effect was also visible in the United States, where inventories remained below their recent five-year averages. For the week ending July 17, U.S. crude stocks were 6% below the five-year average, gasoline stocks were 7% below it and distillate stocks were 10% below it.

The economic impact: a stagflationary supply shock

Fuel scarcity affects the wider economy through costs as well as prices. Higher diesel prices raise the expense of moving goods, operating farm equipment, building infrastructure and running industrial machinery. Businesses can pass those costs to customers, absorb them through lower margins or reduce activity.

The result is a potentially stagflationary combination: higher consumer prices alongside weaker real household income and slower economic activity. The pressure is greatest in sectors that cannot quickly substitute away from diesel or secure long-term supply.

Low inventories make the outlook more fragile. Even if demand remains unchanged, another attack, shipping interruption or refinery outage could trigger a disproportionate price response because buyers have less stock to draw on. Conversely, sustained inventory rebuilding would reduce that risk and help narrow refining margins.

Why the outlook is unusually uncertain

The supplied evidence describes two competing forces. On one side, the IEA reported in August that Gulf production remained 8.3 million barrels per day below pre-war levels and that regional exports had fallen after the Strait was effectively closed again in early July. Russian refining also remained depressed, and fuel exports from Russia were restricted after attacks on its refineries. 26

On the other side, the EIA says a June 18 memorandum between the United States and Iran was intended to end the conflict and was followed by increased traffic through Hormuz. Its forecast expects crude output and trade flows to return near pre-conflict levels by year-end, with most shut-in production restored by early 2027.

Those assessments are not fully consistent, so the duration of the crisis should be described as conditional rather than certain. A durable agreement and reliable shipping security could ease crude prices relatively quickly. Refined fuels would likely take longer to normalize because refineries must restart safely and inventories must be rebuilt, but the evidence provided does not establish a definitive repair timetable for every damaged Gulf facility.

What would bring relief?

The fuel market would need three improvements at the same time:

1. Safer and more consistent Hormuz transit, allowing crude and product cargoes to move normally.
2. Restored refinery operations in the Middle East and Russia, increasing diesel, gasoline and jet-fuel production.
3. Inventory rebuilding, especially for distillates, so buyers are less exposed to the next disruption.

The key lesson is that crude recovery does not guarantee an immediate return to cheap gasoline or diesel. The conflict exposed a narrower and more difficult bottleneck: the world’s ability to refine, transport and store finished fuel. Whether prices ease materially will depend less on headline crude production alone than on the restoration of that entire chain.