The U.S. and Israel attacks on Iran are focusing attention on the Strait of Hormuz, a narrow but strategically vital waterway in the region that serves as a key artery for global oil shipments.

The passage of oil tankers and other commercial ships has all but halted in the strait, sparking concerns that a prolonged conflict in the region could constrain global oil supplies, according to economists. Crude prices, which traded in the mid-$60 range in the days before the start of military operations on February 28, have soared above $100 a barrel for the first time since 2022.

“The combination of an escalating conflict (including Israeli attacks on Iranian fuel depots), the ongoing disruption of Hormuz and announcements of producer shut-ins indicates the crisis is unlikely to be resolved any time soon,” energy analysts with Eurasia Group, a political risk consulting firm, said in a March 9 report.

Here’s what to know about the Strait of Hormuz.

What is the Strait of Hormuz?

The strategic sea passage, located on Iran’s southern border, connects the Persian Gulf to the Gulf of Oman and the Arabian Sea. Long an important commercial trade route, the Strait of Hormuz ordinarily enables the flow of about 20% of global oil — roughly 15 million barrels of crude per day — along with liquefied natural gas shipments. Experts describe it as a strategic “choke-point” for crude. 

The strait — almost 100 miles long and 21 miles wide at its narrowest point — allows the world’s largest vessels to transport oil and gas from the Middle East to China, Europe and the U.S. Most of that crude comes from Saudi Arabia, United Arab Emirates, Iraq, Kuwait, Qatar and Iran. 

What is happening in the Strait of Hormuz?

The Iran war has brought the passage of oil tankers through the strait to a virtual standstill. As a result, oil prices spiked have surged on concerns that a prolonged disruption of crude supplies in the region could sharply boost energy costs, including U.S. gas prices. 

“It is de facto closed in that no one dares to go through,” Arne Lohmann Rasmussen, chief analyst at Global Risk Management, a provider of energy market insights, told CBS News. “You can be attacked, and you can’t get insurance or it is extremely expensive, so you have to wait until the security situation is better.”

“If oil and gas coming from the strait is cut off, that has significant ramifications for the market,” he added. “While there is no physical blockade, threats from the Iranians, plus drone and missile attacks, mean tankers are not going through the strait.” 

A critical question moving forward is the duration of the war and how long the strait remains too dangerous to traverse, analysts said. 

“If the reduction in tanker traffic continues for a week or so, it will be historic. Beyond that, it would be epochal for the oil market with prices rising to ration scarce supply and impacts in financial markets,” S&P Global head of crude oil research Jim Burkhard said in a report. 

How high could oil prices rise if the strait remains closed?

Energy experts said an extended conflict in Iran that locks up the Strait of Hormuz could keep oil prices above $100 barrel, driving up gasoline and other energy prices. 

As of March 9, the national average gas price in the U.S. had jumped to $3.45 per gallon, up more than 51 cents over the last week and roughly 42 cents from a year ago, according to tracking service GasBuddy.

“In just a week, consumers have seen gasoline prices surge at one of the fastest rates in years after oil prices spiked following U.S. strikes on Iran and the effective closure of the Strait of Hormuz,” Patrick De Haan, head of petroleum analysis at GasBuddy, said in a report. “With additional attacks across the Middle East over the weekend pushing oil above $100 per barrel for the first time in years, fuel markets are now rapidly recalibrating to the risk of prolonged disruption to global supply flows.”

That said, Iran could struggle to indefinitely throttle ship traffic through the Strait of Hormuz as the U.S. and Israel degrade the country’s navy and other military capabilities, according to analysts. Blocking Iranian oil from being exported to markets overseas would also badly damage the company’s fragile economy, experts note.

To address such concerns, President Trump on March 3 said that the U.S. International Development Finance Corporation would provide insurance to all ships passing through the Persian Gulf. Mr. Trump also said the U.S. Navy would escort tankers through the Strait of Hormuz, if necessary. 

Are there alternatives to the Strait of Hormuz?

Oil that ordinarily would pass through the Strait of Hormuz by ship could be exported via other routes. 

Those include the East-West Pipeline, also known as Petroline, a nearly 750-mile-long pipeline in Saudi Arabia that delivers oil to ports on the Red Sea. Shipments could also be diverted to the Abu Dhabi Crude Oil Pipeline, a roughly 400-mile pipeline in the United Arab Emirates that transports oil to a facility on the Gulf of Oman.

Yet such alternative routes can only accommodate a fraction of the volume of oil that ordinarily passes through the Strait of Hormuz on a daily basis, according to experts.