U.S. military strikes on the Yemen-based Houthi militants will be “unrelenting” until the group stops shooting at civilian and military vessels in the Red Sea, the Pentagon chief said.

“This campaign is about freedom of navigation and restoring deterrence,” Pete Hegseth said in an interview on Fox News’s Sunday Morning Futures on March 16, speaking a day after the first strikes on the Houthis since President Donald Trump returned to power. “The minute the Houthis say, ‘We’ll stop shooting at your ships, we’ll stop shooting at your drones,’ this campaign will end. But until then, it will be unrelenting.”

Oil prices rose slightly in early trading on March 17, partly because of the strikes, with Brent crude up 0.7% to just over $71 a barrel.

“Although the U.S. has been striking at Houthi target for over a year, the scope and scale of this new campaign, including the targeting of senior Houthi figures, marks a significant escalation in the conflict,” Eurasia analysts Firas Maksad and Gregory Brew said in a note to clients.

On March 15, Trump said he ordered “decisive and powerful” action against the Iran-backed Houthis. In a post on his social media platform Truth Social, Trump said they had “choked off shipping in one of the most important Waterways of the World, grinding vast swaths of Global Commerce to a halt.”

The Houthi health ministry said 53 people, including five children and two women, were killed and 98 injured in strikes on the capital, Sana’a, and other provinces, according to Saba.

On March 16, the Yemeni Armed Forces said it retaliated by launching missile and drone attacks against the USS Harry S. Truman aircraft carrier twice in 24 hours. The statement couldn’t be immediately verified.

Trump said attacks on American vessels “will not be tolerated.”

The Yemeni statement followed a promise by the Houthis’ ruling political council to counter U.S. “aggression,” saying its operations would continue until Israel ended a ban on aid entering Gaza.

Israel stopped aid supplies entering the Palestinian territory around a week ago, saying the move was necessary to pressure Hamas and get it to release more hostages. The Houthis began their maritime attacks in the southern Red Sea and Gulf of Aden in late 2023, ostensibly in support of the Palestinians after the Israel-Hamas war erupted in Gaza.

The attacks rattled shipping markets and pushed up freight rates for vessels traveling between Asia and Europe.

Hamas is also backed by Iran and, like the Houthis, designated a terrorist organization by the U.S.

Hegseth said the latest U.S. strikes were also a warning to Iran. “Iran has been enabling the Houthis for far too long. They better back off,” he said.

White House National Security Advisor Mike Waltz said the attacks over the weekend were successful.

“We hit the Houthi leadership, killing several of their key leaders last night — their infrastructure, the missiles,” Waltz said to Fox News on March 16. “We just hit them with overwhelming force and put Iran on notice that enough is enough.”

Speaking in a separate appearance on ABC, Waltz said Iranian targets in and around Yemen — including ships near the coast that provide intelligence and trainers — “will be on the table, too.”

Regional Escalation

The Eurasia analysts said it was possible the Houthis would opt to target oil-rich Gulf countries again in response to the U.S. attacks. Until a truce in Yemen’s civil war in 2022, the Houthis were regularly firing missiles and drones at Saudi Arabia and, to a lesser extent, the United Arab Emirates. Those helped push up crude prices.

U.S. Secretary of State Marco Rubio said the Houthis had attacked U.S. naval vessels in the area 174 times over the last 18 months, in addition to disrupting global shipping. Asked if there were any plans for U.S. ground operations in Yemen, Rubio said that looked unlikely.

“Those are military decisions to be made, but I’ve heard no talk of ground raids,” Rubio said to CBS. “I don’t think there’s a necessity for it right now.”

The U.S., U.K. and Israel have regularly struck Houthi targets in Yemen, including radar stations and fuel- and missile-storage sites, over the past year. While those have weakened the group and the intensity of its attacks have slowed, it’s still able to carry out assaults.

The Houthis have repeatedly said their missile and drone strikes in the Red Sea area, and directly against Israel, will stop once the war in Gaza is over.

Hamas, which triggered the conflict by attacking Israel from Gaza on October 7, 2023, and Israel began a ceasefire in mid-January.

That truce officially ended early this month, without an agreement on how it should be extended and leaving the conflict in limbo, with Hamas still holding hostages. While Israel hasn’t restarted a full-on conflict with Hamas, it says it could be forced to do so if the group doesn’t lay down its arm and release all the remaining captives.