Iran war has blocked the Strait of Hormuz, a vital oil choke point. Reopening it is a big challenge

Former naval officers who have served in the Hormuz passage say vessels would be sitting ducks, with little room for maneuver in the strait's narrow shipping lanes, if foreign naval forces attempted to reopen the waterway before a cessation of hostilities.

“In today’s context, sending warships or civilian vessels into the Strait of Hormuz would be suicidal,” French navy retired Vice Adm. Pascal Ausseur said in an interview with The Associated Press.

A ceasefire agreement with Iran “would make the situation shift from suicidal to dangerous. At that point, military ships could be deployed. And then escort operations could begin," he said.

Here's a look at how Hormuz might be made navigable again:

Battle-hardened in the Red Sea

French, American, British and other naval crews already have valuable experience of fighting off missiles and drones in the region. They have escorted and defended cargo vessels through attacks in the Red Sea carried out by Iran-backed Houthi rebels in Yemen.

French frigates used machine guns, cannons and sophisticated air-defense missiles to fend off Houthi strikes. French frigate Alsace downed three ballistic missiles in the Red Sea in 2024 as it was escorting a container ship. The ship's commander at the time, Capt. Jérôme Henry, told the AP that being on the receiving end of the potentially deadly strikes was unnerving and exhausting. The sea battles also took a toll on U.S. Navy ships and personnel.

“There were repeated attacks, either by drones or missiles,” Henry said in an interview. “The crew didn’t get much sleep.”

French retired Vice Adm. Michel Olhagaray, a former head of France’s center for higher military studies, says that “all navies learned a great deal” about working together and escorting ships from their Red Sea missions and have also drawn on Ukraine's experiences against Russian barrages of missiles and drones during Moscow's war.

“It would allow us to deploy to that region with fairly refined know-how and a high level of cooperation — and that is extremely important,” said Olhagaray, who commanded a French frigate that patrolled the Strait of Hormuz during the Iran-Iraq war in the 1980s.

Higher risks

Iran is militarily far better equipped than its Houthi proxies in Yemen, which caused considerable damage and disruption in the Red Sea between November 2023 and January 2025. Armed by Iran, the rebels targeted more than 100 merchant vessels with missiles and drones, sinking two and killing four sailors, and greatly reduced trade flows.

Iran can reach all of the Strait of Hormuz and its approaches with anti-ship cruise missiles that it developed off Chinese-made weapons, according to mapping by the U.S. Defense Intelligence Agency. It can also target vessels with longer-range missiles, drones, fast attack craft and naval mines, which it used during the Iran-Iraq war. U.S. strikes on mine-laying Iranian vessels in this latest conflict underscore the gravity of that danger.

With war raging, the Hormuz passage is “very, very dangerous” and the risks for shipping are “much greater” than in the Red Sea against the Houthis, Olhagaray said.

“The means to counter this threat must be far more substantial and far more effective,” he said. “Before the heat can decrease ... most of the offensive installations on land in Iran would have to be eliminated. There would need to be constant monitoring, patrols, extremely close surveillance, and a very high level of intelligence to be able to say that it would be possible to allow tankers to transit, even with military escorts.”

“That will not happen at all — not at all — in the near future.”

Reassuring insurers

Experts say another challenge will be reassuring shipping insurers and companies that navigating in Hormuz waters is feasible again. Insurance premiums for shipping in the strait have soared to levels that France's transport minister described as “insane," causing “a big problem” for shippers.

“Maritime traffic is a business. That business has to make money. If insurance costs are so high that you can’t make a profit by sailing through a given area, then you don’t sail through that area,” said Ausseur, now a director of the Mediterranean Foundation for Strategic Studies, a think tank.

Insurance rates for oil tankers that want to transit through Hormuz are many times higher than they were before the war and are approaching levels that have been charged for ships carrying grain from Ukraine during the ongoing war with Russia, said Marcus Baker, global head of marine, cargo and logistics for insurance broker and risk adviser Marsh Risk.

Potential naval escorts for commercial ships “would be helpful,” Baker said.

“That’s been done before in conflicts past, so that’s not something unusual and that will obviously give a degree of confidence to the insurers that the vessels are going to have a greater degree of safety,” he said.

Mae Anderson in New York, and Sylvie Corbet in Paris, contributed to this report.