Iran war and oil disruption
The world is six months into the Iran war. In that time, ceasefire agreements have broken down, while the US offensive has shifted from airstrikes to economic sanctions and naval blockades. The situation remains fluid and susceptible to change.
What has not changed is that another oil shock remains the biggest risk to inflation and interest rate outlook.
In August, the International Energy Agency (IEA) estimated that the global oil market would face a supply deficit of 1.8m barrels per day in Q3 2026, more than double its July estimate of 800,000 barrels per day.
The sharp revision goes to show just how difficult it is to forecast the oil markets right now. Conditions are constantly changing, as highlighted by IEA’s report that an expected recovery of Gulf oil supply following the June ceasefire was disrupted by renewed hostilities.
The global oil market has relied partly on existing inventories to bridge the gap between supply and demand. But the IEA has warned that the inventory buffers are “rapidly depleting” and noted the urgency of the re-opening of the Strait of Hormuz.
Following the expiration and non-renewal of the ceasefire between the US and Iran on 17 August, the Hormuz Strait Monitor reported that the Strait was operating at 1% of pre-war traffic with “effectively zero tankers moving.” At the same time, tankers using the Red Sea as an alternate route to transport crude have faced persistent missile attacks from the Yemen-based Houthi group.
Diplomatic efforts are continuing with Qatar stepping up as the mediator. Reuters reported that Iran and Oman were working on a deal to re-open the Strait, manage traffic and potentially share its revenues. Progress, however, depends on a list of Iranian demands reportedly including an end to US blockade, sanctions relief and compensation.
Pessimism remains high, with prediction markets showing just a 3% chance of the Strait of Hormuz returning to normal by the end of September.
In the US, President Trump looked to shore up American energy independence by signing an agreement with Venezuela to access the South American nation’s rich crude oil reserves. The deal will let American companies develop 17 oil fields with proven oil reserves of 65bn barrels, Venezuela’s acting President Delcy Rodríguez said in a statement posted on Telegram on 29 August.
Chevron [CVX] – the only US oil producer actively producing in Venezuela – was reportedly finalising deals that would give it greater control over its Venezuelan operations and allow it to expand oilfields.
Rivals ExxonMobil [XOM] and ConocoPhillips [COP] were reported to remain on the sidelines, according to the Wall Street Journal, as the firms seek compensation from the Venezuelan government for nationalising their assets in 2007.
US oil majors have emerged among the biggest winners of the oil supply shock. CVX, XOM and COP reported multi-year high quarterly profits during the July-August earnings season, and have returned between 30% and 42% year-to-date to August end. The iShares US Oil and Gas Exploration and Production ETF [IEO] has returned about 52% in the same period.
Oil services company Halliburton [HAL] was also reportedly in talks to provide equipment to oil producers in Venezuela. SLB [SLB] and Baker Hughes [BKR] are also said to be exploring opportunities.
More broadly, higher oil prices and expectations of increased drilling have benefitted drilling contractors such as Nabors Industries [NBR] and Helmerich and Payne [HP], up 68% and 52% year-to-date, respectively. Refiners have also benefitted, with Marathon Petroleum [MPC] more than doubling its share price in 2026, supported by surging global refining margins.
At the other end of the spectrum are airlines, which have faced a sharp increase in fuel cost. The jet fuel crack spread – the price difference between crude oil and refined fuel – surged from about $20 per barrel in January to about $67 per barrel in the fourth week of August, data compiled by the International Air Transport Association showed.
In August, Delta Air Lines [DAL], American Airlines [AAL], Southwest Airlines [LUV] and United Airlines [UAL] fell between 10% and 14%. International peers also declined, with Australia’s Qantas [QAN] down about 5.3%.
At the end of August, Brent crude prices traded over 20% above their pre-war prices at about $90 per barrel.
The Fed entered 2026 on a monetary easing path. The Iran war changed that. Six months on, the initial shock has faded, but the war remains a major risk to inflation, interest rates and even to the AI infrastructure buildout, where investors are starting to show nerves over its expensive financing costs.