Chevron's Wirth: Oil Buffers Cushioning Iran War Shock Are 'Drained'

U.S. diesel hit a record $6.53 a gallon on Sept. 22 — up from roughly $3.76 before the Iran war began in late February — and Chevron CEO Mike Wirth says the emergency tools that softened that shock are nearly exhausted.

"Those are all buffers in the system that have bought us time, but they've been drained," Wirth told CNBC's Squawk Box Europe on Oct. 7. "And so we're at much lower levels of inventory right now, and it makes the system more vulnerable to disruption." He called it "a very serious situation."

The numbers behind his warning are straightforward. Wirth said the world entered 2026 "with high inventories" — commercial stocks held by companies plus strategic reserves held by governments. Since the U.S. and Israel launched the war in late February, companies have drawn down commercial inventories, governments have released emergency stocks, and sanctioned barrels have reached buyers. For operators and fleet managers, that means each new disruption now hits price directly, with no cushion underneath.

What does the IEA forecast change for diesel buyers?

Quite a lot, and none of it good. In its October Oil Market Report, released Wednesday, the International Energy Agency said the diesel market will stay tight well into 2027 and hinges on a recovery of Middle East fuel supply. Benchmark diesel prices have eased from September's records above $200 a barrel, but remain nearly double both crude prices and their pre-crisis levels.

The agency doesn't expect depleted diesel stocks to be rebuilt beyond normal seasonal swings before the second half of 2027. Its supply math: global oil output falls an average of 5.8 million barrels a day this year, to 100.7 million barrels a day, before rebounding in 2027. The market stays in deficit through year-end. High prices will cut global oil demand by 2.6 million barrels a day in 2026, with diesel accounting for about a quarter of that drop.

In California, the pain is sharper still — the statewide average has topped $8 a gallon, according to AAA data cited by CBS News. For a trucker burning 100 gallons a day, the move from $3.76 to $6.53 adds roughly $277 to a daily fuel bill.

How has Washington responded?

With the Nov. 3 midterms under three weeks away, fuel costs have become a political liability. An AP-NORC poll published Oct. 1 found Americans disapprove of President Donald Trump's handling of the Iran war and blame him for higher prices, Fortune reported.

The policy scramble has been fast-moving:

• Sept. 27: Trump floated a U.S. diesel export ban, telling a Fox News reporter, "We're thinking about it very seriously," while conceding it could push gasoline prices up. Refiners warned it would backfire by forcing output cuts. Wirth called the idea "unwise," saying "export bans, be they in the U.S. or in other countries, actually take supply off the global market and they run the risk of making the situation worse."
• Oct. 2: Trump shelved the ban after the G7, under U.S. pressure on Europe, agreed to release 100 million barrels of crude and diesel from emergency reserves over four months, front-loading diesel in the first 20 days. "We're not going to be doing the export ban," Trump told reporters.
• Oct. 5: He signed an executive order letting truckers and farmers use red-dyed diesel — normally off-road only and exempt from highway fuel taxes — on public roads. The order defers the 24.4-cent-per-gallon federal excise tax through Dec. 31 and directs Treasury to explore canceling it entirely. GasBuddy's Patrick De Haan was blunt to Fortune: the waiver "doesn't add supply globally."
• Oct. 9: Trump announced Russian President Vladimir Putin had agreed to supply more than 4 million tons of diesel to global markets in stages, with Treasury waiving sanctions on Russian diesel through April 7, 2027.

Will the Russia deal actually move prices?

Probably not. Ukrainian drone strikes on Russian refineries have gutted the country's fuel output: Russian diesel and gasoil exports fell to about 144,000 barrels a day in September, a decade low. Some analysts doubt Moscow can deliver the volumes Trump announced. The IEA said easing Russian export restrictions is unlikely to materially change the global diesel balance, because the bottleneck is a lack of working refinery capacity — not sanctions.

The deal also drew bipartisan backlash in Congress and a sharp rebuke from Ukrainian President Volodymyr Zelensky, who wrote on X: "allowing Russia to sell petroleum products is an investment in a war that must be ended, not prolonged."

Which brings it back to Wirth's core point. Stockpile releases, sanctions waivers, and tax deferrals buy time, but they can't replace the oil and fuel that isn't flowing out of the Middle East. With the buffers already spent and the IEA's deficit running through year-end, the practical read for businesses is simple: budget for tight diesel — and real price relief — no earlier than the second half of 2027, and treat any fresh supply disruption as unhedged.