Yemen's Iran-aligned Houthis announced Monday they would impose a maritime blockade on Saudi Arabia, further throttling a global energy market already greatly restricted by Iran's closure of the Strait of Hormuz.
This is why it matters and what it means for the Iran war and the global energy crisis.
It is not clear how the Houthis would carry out a maritime blockade of Saudi Arabia, its northern neighbor along the Red Sea coast, or whether it would include a return to attacks on shipping.
Yemen sits on the Bab el-Mandeb strait – the southern gateway to the Red Sea – and closing that would open up a new front in the energy crisis and Iran's overarching conflict with the U.S.
With the Strait of Hormuz already disrupted, the Red Sea has become a critical alternative outlet for Gulf oil and other products. A serious disruption would mean both of the Middle East's major oil export routes are shut simultaneously.
Iran's partial blockade of the Strait of Hormuz after Israel and the U.S. attacked it on Feb. 28 disrupted most oil and other exports from the Gulf, raising prices and delivering a global energy shock.
Saudi Arabia responded by diverting more than 70% of its normal daily crude exports to the Red Sea port of Yanbu. Ships from Yanbu bound for Europe go north through the Suez Canal. Those heading to Asia go south through Bab el-Mandeb.
Shipments from Yanbu averaged 4 million barrels per day in recent weeks according to data from Kpler and Signal Ocean, up from around 973,000 bpd a year earlier.
Total petroleum volumes transiting Bab el-Mandeb amounted to 7.4 million bpd in June, or about 7% of global oil output, according to Kpler data, up from 4.2 million bpd last year.
That has provided a lifeline for the energy market, helping to keep down global oil prices. Saudi Arabia is considering an expansion of its crude oil pipeline to the Red Sea coast, Reuters reported last week.
When the Houthis launched attacks on Red Sea shipping in November 2023, Gulf oil exports were flowing freely.
The Houthis have been in a civil war against the Saudi-backed, internationally recognized government for more than a decade and have attacked Gulf neighbors with missiles and drones.
However, a 2022 truce between the country's warring sides largely held until last week, when Yemen's internationally recognized government said it had struck Sanaa airport to stop an Iranian plane landing.
The Houthis said Saudi Arabia was responsible and, in response, fired missiles at Abha airport in the kingdom's mountainous southwest.
A senior Houthi official, politburo member Mohammad al-Farah, then warned in an interview on Iran's Press TV website that if the situation kept escalating, Bab el-Mandeb would be closed.
The U.S. says Iran has armed, funded and trained the Houthis with help from Hezbollah. The Houthis deny being an Iranian proxy and say they develop their own weapons.
It is not clear how far the group's stance on Bab el-Mandeb and the Red Sea stems from its own strategic priorities or is being made on Iran's behalf.
After Israel's genocidal campaign in Gaza, the Houthis began firing at Israel and on shipping in the Red Sea, saying they were doing so in support of Palestinians.
The attacks severely disrupted global shipping, prompting Maersk, Hapag-Lloyd and other major companies to divert around Africa – a far longer, more expensive route.
Red Sea traffic has not recovered since, with traffic through the Suez Canal down 52% in 2025 versus 2023 levels and at its lowest in at least 50 years, Suez Canal Authority data shows.
A U.S.-led mission to restore free navigation in the Red Sea involved repeated strikes on Houthi targets and a campaign that shot down hundreds of drones and missiles.
But some Houthi attacks continued until last summer, only ending completely with the Gaza cease-fire in October.
Last month, the Houthis said they would ban ships linked to Israel from the Red Sea after Israel renewed military attacks on Iran.
However, that threat was never acted on and shipping groups Maersk and Hapag-Lloyd are resuming some Red Sea routes that they had abandoned during the Houthi attacks last year, Maersk said this month.
While Hezbollah and the Iraqi groups joined the war early with rocket and drone fire after the first U.S. and Israeli strikes on Iran, the Houthis had been comparatively quiet.
The group's leader Abdul Malik al-Houthi said on March 5: "Our fingers are on the trigger at any moment should developments warrant it."
Iranian commanders have repeatedly warned that the Houthis could join the war. The Houthis launched a few missile and drone attacks on Israel in late March and early April.
Revolutionary Guards Quds Force commander Esmaeil Qaani said on June 1 they could choke off the Red Sea.
That may now have changed with their announcement of the blockade on Monday against Saudi Arabia in retaliation for what they called the kingdom's siege of its ports and airports, including last week's strike.
