TOKYO (Japan Times) - Diesel prices have never been higher. U.S. President Donald Trump contends that’s not because of the war he started nearly seven months ago.
“The World’s Diesel price rise is mostly caused by the Russia/Ukraine War, not Iran,” Trump said in a social media post this week. He’s since reiterated the assertion.
But according to estimates compiled by Bloomberg and double-checked with diesel traders, the Iran war has removed more diesel supply from the market than the Russia-Ukraine conflict.
From March to August, estimates from energy analytics companies, Energy Aspects, Kpler and Vortexa, imply an average loss of about 770,000 barrels a day from the Middle East compared to the same period in 2025. That’s more than twice the roughly 350,000-barrel-a-day loss of Russian supplies over the same time-frame.
The global energy market was thrown into disarray this year, with a widely expected oil glut erased by the U.S-Israeli aggression on Iran. Crude prices soared after the U.S. and Israel attacked Tehran at the end of February, with supply squeezed through the Strait of Hormuz. 
Critically, the loss of Russian supplies occurred months into the Iran war, during which the world’s fuel and crude oil stockpiles drew down — leaving little cushion to absorb the blow.
“In pure volumetric terms Iran is bigger,” Eugene Lindell, head of refined products at consultancy FGE NexantECA, said of the war-driven loss. “But, of course, prices are set at the margin,” he said. Taking hundreds of thousands of further barrels off the market “turned a super tight market into a historically tight one.”
As a country, Russia is typically the world’s second-largest exporter of diesel, the industrial fuel essential for everything from freight to agriculture. In 2024, it averaged around 930,000 barrels a day of exports of the fuel, according to Vortexa.
But taken as a region, the Middle East is a more prolific shipper, exporting around 1.7 million barrels a day in the same year.
Trump, in his social media post, said Moscow and Kyiv had agreed to stop attacks on energy infrastructure. Ukrainian President Volodymyr Zelenskyy said no deal had been finalized and strikes have continued this week. Russia’s diesel export ban may be extended through October.
European diesel futures rose over 100% in the early months of the Iran war, while U.S. contracts also soared. Those prices cooled as the U.S. and Iran agreed to a temporary ceasefire. But as the U.S aggression on Iran re-escalated and Russian exports collapsed, prices climbed once more, eclipsing the springtime highs. 
“Iran war-related shortages are the biggest driver of the diesel and product shortage and price spike, though damage to Russian refineries is exacerbating these trends,” said Rachel Ziemba, adjunct senior fellow at the Center for a New American Security, a Washington-based think tank. “A ceasefire that leads to repair of refineries and return of Russian products would ease some pressure.”