When US and Israeli forces struck Iran on 28 February 2026, oil markets were closed for the weekend. By the time trading resumed on Monday 2 March, the world had a war in the Persian Gulf, a dead supreme leader, an Iranian vow of retaliation and the looming closure of the Strait of Hormuz. Brent crude jumped 8% in those two trading days, from $71.32 a barrel on 27 February to $77.24 on 2 March and that was only the beginning.
The first surge: February to March
The opening weeks of the war were catastrophic for energy markets. Iran moved quickly to disrupt shipping in the Gulf, attacking tankers and energy facilities across the region. Tehran began attacking ships and energy facilities, closing navigation in the Gulf and grinding energy production to a halt from Qatar to Iraq. By 11 March, Brent had reached around $91 a barrel, already 27% higher than the day before the war. By 15 March it was at $103.90, a 43% increase compared to the pre-war price.
The worst was yet to come. On 18 March, Israeli strikes hit Iran's South Pars gas field and nearby petrochemical facilities in Asaluyeh, the first known strike on Iran's upstream energy infrastructure in the conflict, sending Brent back above $108. Days later it climbed further still. By 30 March, Brent had surged past $115 a barrel after Houthi forces launched their first attacks on Israel, widening the conflict. Brent climbed 59% in March alone, its steepest monthly gain since the 1990 Gulf War. By the end of the month and into early April, Brent surged over 60% in March, its biggest monthly gain since records began in 1988.
The peak: April and the $138 high
Brent reached as high as $138 a barrel on 7 April, averaging $117 for the month as a whole, the highest monthly average since June 2022 following Russia's invasion of Ukraine. The Strait of Hormuz, through which roughly one-fifth of the world's oil and gas normally flows, had effectively ceased to function as a trading route. Traffic through the strait had largely been at a standstill, both because of the risk of attacks on tankers and a new US blockade against Iranian oil shipments.
Then, on 8 April, the ceasefire arrived. After the US and Iran agreed to a conditional two-week ceasefire including a commitment to restore navigation through the Strait of Hormuz, Brent crashed by nearly 16%, falling below $100 a barrel.
May's false hope
As ceasefire talks continued through May and optimism grew over a possible 60-day extension of the truce, oil prices continued to fall. Brent was down almost 19% for the month of May, closing at $92.56 on 29 May, its worst monthly performance since the Covid-19 pandemic. However, crude loadings inside the Gulf remained extremely low, with Iran's crude loadings for May below 0.3 million barrels per day, down sharply from April's average of 1.5 million barrels a day. The Strait of Hormuz remained effectively closed. Peace talk optimism was driving prices down even as the underlying supply disruption continued.
The ceasefire breaks down
In early June, fresh Israeli strikes in Lebanon and Iranian attacks on US bases in Kuwait and Bahrain sent prices rising again. When Trump told CNBC he "couldn't care less" whether Iran negotiations were over, West Texas Intermediate futures rose more than 5% and Brent advanced more than 4% to close at $94.98, with contracts up more than 30% since the war began on 28 February.
On Sunday 7 June and into Monday 8 June, the ceasefire collapsed in its most serious rupture yet. Israel struck Beirut, Iran fired ballistic missiles at Israel, Israel struck back at targets across Iran including the Mahshahr petrochemical complex, and the Houthis declared a naval blockade of Israel in the Red Sea. Brent futures jumped more than 4% to above $97 a barrel on Monday, with investors focused on further potential disruption to the Strait of Hormuz.
The bigger picture
One hundred days into the war, Brent sits at around $97 a barrel, roughly 36% above where it traded the day before the first strikes. The price has swung violently in both directions, driven less by conventional supply-and-demand dynamics than by the daily rhythm of diplomacy and destruction. Every ceasefire rumour has sent prices lower; every strike on energy infrastructure has sent them higher. The Strait of Hormuz, the single most important artery in global energy trade, remains compromised. The US Energy Information Administration has projected that once Hormuz flows gradually resume, Brent could fall to an average of $89 a barrel by the fourth quarter of 2026, with most pre-conflict production and trade patterns not fully restored until late 2026 or early 2027. For now, every day the war continues is another day that projection remains out of reach.
Sources: US Energy Information Administration, CNBC, Trading Economics, Reuters
