Oil rises after U.S. strikes Iran over Hormuz ship attacks

Oil prices advanced Wednesday after the U.S. military said it launched new strikes against Iran in response to attacks on commercial vessels in the Strait of Hormuz, raising the risk that a recent Middle East ceasefire could weaken. CNBC market data showed West Texas Intermediate futures for August delivery up 2.87% at $72.46 a barrel, while September Brent crude futures rose 2.75% to $76.18.

The U.S. Central Command said on X that it had begun a “series of powerful strikes” against Iran after three commercial ships came under attack while transiting the Strait of Hormuz on Tuesday. CENTCOM warned that Tehran would face “heavy costs” for targeting commercial shipping.

“The U.S. 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,” CENTCOM said in the post.

The Strait of Hormuz is a vital route for the region’s oil and gas shipments. It had been effectively blockaded since war between the United States and Iran broke out in late February, according to CNBC, before a provisional peace deal last month was intended to reopen the passage to commercial traffic.

The renewed military action tests that arrangement only weeks after it was reached. The ceasefire’s economic significance rests on access: when ships can pass through the Strait, cargoes can move through a key regional chokepoint; when security deteriorates, vessels, insurers and commodity traders face higher uncertainty around transit.

The U.S.-led Joint Maritime Information Center said three vessels were attacked in or near the Strait of Hormuz on Tuesday. The center raised its threat assessment for ships using the waterway to “severe” and warned that further hostile action by Iran was likely.

Washington also moved on sanctions. The U.S. Treasury Department on Tuesday withdrew a waiver that had allowed Iran to sell its oil, according to CNBC. Removing the waiver takes away an exemption that had permitted those sales despite U.S. restrictions.

A U.S. official told CNBC, speaking on condition of anonymity to discuss private talks, that Iran’s conduct would determine whether it received benefits under the diplomatic arrangement. “Iran will only reap benefits if they exhibit good behavior,” the official said. “Iran’s actions in the Strait were wholly unacceptable to the United States and will be met with consequences.”

The oil market reaction centered on the possibility that the security situation in Hormuz could again disrupt trade flows. The reported gains in WTI and Brent reflected the immediate move in benchmark futures after the U.S. strikes and the warning to ships transiting the waterway.

This story draws on original reporting from CNBC.