U.S. military vexed by elusive enemy in the Strait of Hormuz

U.S. victory in Iran hinges on the battle for the Strait of Hormuz, a critical shipping lane for the world’s oil supply that Iran has blocked with mines, drones and small attack sea vessels that experts say American and Israeli military will have difficulty eliminating.

U.S.-flagged tanker Stena Imperative was among at least 18 commercial vessels Iran has attacked in the Persian Gulf as it employs unconventional warfare to maintain a stranglehold on the strait.

Oil prices have soared 38% since the war started, from $70 a barrel of Brent crude, the international standard, to more than $95 a barrel, thanks to a panic over the prospect of oil shortages and warnings that reopening the strait could take weeks or months.

While the U.S. and Israeli forces have destroyed much of Iran’s conventional navy as well as its missile stockpiles and launchers, Iran’s arsenal of thousands of sea mines and hundreds of speedboats, underwater attack drones and unmanned surface vessels has enabled it to practically halt all traffic through the strait since shortly after Operation Epic Fury began on Feb. 28.

Eliminating the Iranian threat, which extends from the air above the strait to 100 meters underwater, will be nearly impossible, said Jonathan Schroden, an expert on strategic competition and irregular warfare for the Center for Naval Analysis.

“Whether you’ve got the potential for mines undersea, fast attack craft of hundreds of thousands of small boats on the surface, plus missiles and drones overhead, that integrated threat stack is very, very difficult to deal with under any situation, but especially in the geographical confines of the strait,” Mr. Schroden said.

More than 20% of the world’s oil supply depends on transit through the strait. The strait’s closure also has blocked ships carrying critical supplies of liquefied natural gas, fertilizer, chemicals and grains.

Some analysts believe it will be difficult to end Iran’s hostile control of the waterway without U.S. military forces taking over the strait or escorting tankers, which would impose significant risks to the U.S. naval fleet and U.S. troops.

Energy Secretary Chris Wright said Thursday the U.S. military is likely to start escorting oil tankers through the strait “relatively soon. “

The move would pull U.S. military assets directly into the line of fire, said Caitlin Talmadge, a Massachusetts Institute of Technology professor and global security scholar.

“U.S. naval escorts of traffic in the Gulf would bring U.S. ships and helicopters very close to Iranian shores. This will be risky unless the United States has fully eliminated or suppressed Iranian shore-based threats from missiles and drones, as well as naval dangers like mines and the type of unmanned surface vessel that attacked an Iraqi tanker last night,” she said. “The closer the United States comes to Iran, the easier Iranian targeting becomes and the less time and space U.S. platforms will have to defend themselves.”

Some Middle East security analysts say the U.S. must not back down and should wrest control of the strait from Iran using its military might.

The Iranian takeover of the strait has significantly disrupted global energy supplies and reverberated through the global economy. High oil prices jolted the U.S. stock market into a selloff Thursday.  

“The strait is where the real test of Trump’s resolve against the Islamic Republic begins,” wrote Behnam Ben Taleblu, Iran Program senior director at the Foundation for Defense of Democracies.

The United States has destroyed at least 16 vessels capable of laying mines.

Mr. Taleblu said the United States should eliminate the Iranian Republican Guard Corps navy “comprehensively,” including its fast attack craft, shore-based missile batteries and port infrastructure.

The IRGC said any ship linked to the U.S. or Israel that attempts to pass through the strait will be targeted, and to expect oil prices to rise to $200 per barrel.

Maritime insurers have responded by canceling war risk coverage for vessels operating in the Persian Gulf.

Chinese and Iranian tankers and other non-sanctioned vessels are passing through the strait, which, Treasury Secretary Scott Bessent said, indicates the Iranians “have not mined the straits.”

Mr. Bessent said the U.S. would begin escorting tankers once it has “complete control of the skies” and destroys Iran’s missile capabilities.

The U.S. and Israel continued major strikes on Iranian targets Thursday while Iran indicated it plans to use the strait as leverage to force the two nations to end the bombardment.

The country’s newly ordained Supreme Leader Ayatollah Mojtaba Khamenei, in his first public statement, said the strait must remain closed as “a tool to pressure the enemy.”

Mr. Khamenei, who was reported to be seriously injured in the initial U.S. attack that killed his father, Ayatollah Ali Khamenei, also threatened to attack U.S. military bases in the Middle East.

Two fuel tankers, the Marshall Islands-flagged Safesea Vishnu and the Malta-flagged Zefyros, were attacked by explosive-laden drone boats on Thursday. At least one person was killed, while another 25 crew members were rescued from the tankers by the Iraqi navy.

The Japanese-flagged container vessel ONE Majesty also sustained minor damage from an unidentified projectile while traveling northwest of the United Arab Emirates.

U.S. Central Command released an updated overview of Operation Epic Fury that said American forces have struck about 6,000 targets across Iran with a focus on IRGC command and control centers, ballistic missile and drone sites and Iran’s navy.

The CENTCOM report also indicated that U.S. forces have destroyed or damaged more than 90 Iranian vessels since the start of the war. Officials said Wednesday that U.S. attacks had destroyed more than 30 Iranian mine-laying ships after reports that Tehran was preparing to lay explosives in the Strait of Hormuz.

Mr. Schroden said the U.S. military’s effort to degrade Iran’s military capabilities will take time. In addition to destroying thousands of missiles, it must eliminate thousands of drones and Iran’s ability to produce more of them, thousands of small boats and potentially thousands of mines.

“I don’t see how you get to the point where they’ve attrited enough of Iran’s missile and drone capability to not have at least some residual threat to tankers,” Mr. Schroden said. “As long as that remains, the insurance costs for these companies are going to remain high, and that is the main problem preventing most ships from going through the strait.”

• Vaughn Cockayne contributed to this report.