Oil jumps as U.S. 'powerful strikes' against Iran risk unraveling fragile Mideast truce

Oil tankers and cargo vessels remain anchored off Port Sultan Qaboos on June 21, 2026 in Muscat, Oman. The Strait of Hormuz, a vital shipping route for the region's oil and gas, was effectively blockaded since the outbreak of war between the United States and Iran in late February. On Sunday, U.S. Vice President JD Vance arrived in Switzerland for high-level talks with the Iranian delegation, as the two sides seek to clarify the terms of ending the war.

Elke Scholiers | Getty Images News | Getty Images

Oil prices rose Wednesday after the U.S. launched fresh strikes on Iran in retaliation for Tehran attacking commercial vessels in the Strait of Hormuz.

West Texas Intermediate futures for August delivery rose 2.87% to $72.46 per barrel. Futures for International benchmark Brent crude for September delivery jumped 2.75% to $76.18 per barrel.

The U.S. military said it had begun a "series of powerful strikes" against Iran after three commercial vessels transiting the Strait of Hormuz came under attack on Tuesday, warning Tehran would face "heavy costs" for targeting commercial shipping.

"Strikes are in response to Iranian attacks on three commercial vessels that were transiting the Strait of Hormuz. Iran's demonstrated aggression was unwarranted, dangerous, and a clear violation of the ceasefire," the U.S. Central Command said in a post on X.

The latest exchange threatens to test a fragile ceasefire reached last month that reopened the critical Strait of Hormuz for commercial shipping after months of disruption.

Signaling that things have taken a turn for the worse, the U.S. Treasury Department on Tuesday withdrew a waiver that had allowed Iran to sell its oil.

"Iran will only reap benefits if they exhibit good behavior," a U.S. official told CNBC, speaking on condition of anonymity to discuss private talks. "Iran's actions in the Strait were wholly unacceptable to the United States and will be met with consequences."

Three vessels were attacked in or near the Strait of Hormuz on Tuesday, according to the U.S.-led Joint Maritime Information Center, which raised its threat assessment for ships transiting the waterway to "severe," warning that further hostile action by Iran was likely.

"It's not in Iran's best interest to settle on a deal with their leverage over Trump only increasing the closer we get to November, although yesterday's attacks coincide with the ongoing state funeral ceremonies for Ali Khamenei," said Andrew Jackson, a strategist at Ortus Advisors.

The U.S. midterm elections are due in November, and Mideast conflict-induced inflation stands to raise the political stakes for the Trump administration.

"The corresponding jump in oil and yields and likelihood that the Fed will be forced to take a more hawkish stance with inflation here to stay," he said in an email. The 10-year Treasury yield was trading 2 basis points higher at 4.549%.

— CNBC's Spencer Kimball and Megan Cassella contributed to this report.