On February 28, 2026, the US and Israel launched strikes on Iran. In response, Iran's Islamic Revolutionary Guard Corps (IRGC) announced the closure of the Strait of Hormuz to all ships, prohibiting passage and broadcasting a radio signal to that effect, though Iran did not officially declare such an order. The US Department of Transportation issued an urgent warning for commercial vessels to avoid the Strait of Hormuz, the Persian Gulf, the Gulf of Oman, and the Arabian Sea, following intercepted IRGC communications. Forbes noted that despite the strategic importance of the strait for 30% of global oil trade, Iran was unlikely to sustain a long-term blockade due to US military response, the impact on its own exports, and pipeline alternatives available to Saudi Arabia and the UAE.

On March 1, economic experts assessed that Brent crude could rise to $80 per barrel, but alternative supply routes and increased OPEC+ quotas would mitigate the price spike. By March 2, QatarEnergy suspended LNG production at its Ras Laffan and Mesaieed facilities following Iranian drone attacks, affecting 20% of global LNG supply and causing prices to surge by up to 50%. Iran's military advisor warned that any tankers attempting to export oil through the strait would be attacked. On March 3, Serbian President Aleksandar Vucic warned that Europe would face an energy crisis if the escalation continued, while an analyst at Finam noted that China, South Korea, India, Japan, and Pakistan — which receive more than 80% of their LNG from Qatar — would be the hardest hit.

By March 4, Iran claimed full control over the Strait of Hormuz, making ship movement impossible, with dozens of tankers queued on both sides. Brent crude reached $82.66 per barrel, up 1.55%. The IMF's First Deputy Managing Director stated that the economic impact of the conflict would depend on its duration, infrastructure damage, and whether energy price spikes prove temporary. The US administration acknowledged growing risks to energy markets. The Guardian reported that UK household energy bills could rise by £160 annually from July after gas prices hit a three-year high. On March 5, the IRGC announced it would not allow commercial ships or warships from "enemy countries" — the US, Israel, Europe, and their supporters — to pass, and claimed to have destroyed ten oil tankers.

Oil prices rose 27% by March 7, with markets fearing $150 per barrel and potential inflation. On March 8, Deutsche Welle reported that around 70% of Iran's non-oil trade passes through the strait, so a long-term blockade would hurt Iran's own imports and exports to China and India. By March 9, Brent hit $116.58 per barrel, a 25% increase. Iran conditioned the partial reopening of the strait on the expulsion of US and Israeli ambassadors from countries that wished to resume passage. US President Donald Trump suggested the US might take control of the strait.

After a period of relative calm, on June 1, Iran suspended peace talks with the US via mediators, citing a ceasefire breakdown and clashes in Lebanon. Oil prices jumped about 7%, with Brent crude rising 6.85% to $97.36 per barrel. Multiple reports suggested Iran might clear mines with Oman's support. The US gave contradictory responses, with Trump first saying talks might be over, then stating negotiations continue. On June 2, oil prices fell after Trump claimed he had brokered a halt to Israeli military action in Lebanon. Brent slipped to $94.24. The IRGC Navy reported that 24 commercial vessels had passed through the strait in the previous 24 hours under Iranian coordination. Major LNG producers Qatar and the UAE began hiding their tanker movements — disabling transponders and crossing in pairs — allowing some resumption of shipments.

On June 3, the OECD warned that rural areas in the UK were particularly at risk of diesel shortages. Oil prices rose again as the US military reported Iran had fired ballistic missiles at Kuwait and Bahrain, and conducted strikes on Iran's Qeshm Island. Trump said negotiations were progressing quickly and that a memorandum could allow shipping to resume that week, but also noted the blockade could last until Labor Day (September 7), though he considered that unlikely. A deputy from Gazprom Neft called the blockade unprecedented in oil market history.

On June 4, oil prices fell 3% after an Israel-Lebanon ceasefire agreement was announced, with Brent dropping to $94.76. The Dow Jones surged 877 points to 51,564 on hopes of a broader US-Iran peace deal. However, Hezbollah rejected the ceasefire terms. By June 5, Brent recovered slightly to $95.42 amid a blast at an Omani terminal. Iran's crude oil exports collapsed to an estimated 209,000 barrels per day in May, an 89% drop from March's 1.9 million bpd, as a US naval blockade and sanctions deepened. The head of Rosneft stated that 16 million barrels per day had been lost from the market due to the strait's closure. Al Jazeera reported that the US naval blockade since April 13 had cost Iran an estimated $5.8 billion in lost oil revenues. Iran's deputy parliament speaker threatened to close the Bab el-Mandeb strait if attacks on Lebanon did not stop, and said Iran would adopt a "powerful resolution" on regulating shipping through the Strait of Hormuz.