Ansar Allah's naval blockade on Saudi Arabia in the Red Sea could pose a major challenge to a US military already stretched by its ongoing war against Iran, potentially forcing Washington to divide its forces between two active fronts, current and former US officials said.
Ansar Allah announced Monday that it would prevent ships from loading or unloading at Saudi ports, disrupting the kingdom's oil exports and affecting an additional 7% of global oil supplies.
The threat comes as the United States continues its aggression against Iran, raising concerns that Washington could face a widening regional confrontation that would place further demands on its naval, air, intelligence, and missile defense capabilities.
Saudi Arabia, which hosts US forces, has not requested military assistance from Washington. However, US President Donald Trump suggested on Tuesday that any attempt by Ansar Allah to obstruct shipping through the Red Sea, a vital corridor for global trade, could draw the US into another confrontation.
"If something like that happens, we'll take care of it. We've done that with the Houthis before", Trump told reporters on Tuesday.
For Washington, however, responding to Ansar Allah could prove far more complicated than simply deploying additional forces. The US military is already heavily engaged in the war against Iran, while maintaining a naval blockade of Iranian ports in the Gulf.
"You're bifurcating your admittedly fairly robust resources in the region between two active fronts", said Jason Campbell, a former senior Pentagon official.
Campbell, now with the Middle East Institute, said addressing a Red Sea escalation could require Washington to move warships from the Gulf toward Yemen, potentially weakening its ability to sustain operations elsewhere while creating new demands for air and missile defense.
The potential escalation illustrates the broader strategic consequences of the US war on Iran, which risks expanding into multiple theaters across the region.
A confrontation with Ansar Allah would require Washington to allocate additional military assets to protect shipping and counter potential missile and drone attacks, while continuing its campaign against Iran.
Ansar Allah has demonstrated resilience through years of military operations by a Saudi-led Arab coalition, which failed to defeat the group despite an extensive bombing assault. More recently, the group has also withstood US aggression while maintaining its ability to threaten maritime traffic in the Red Sea and the Bab el-Mandeb strait.
"Ansar Allah have proven many times in the past that they have the ability and willingness to obstruct maritime traffic in the Red Sea and the Bab el-Mandeb Strait," said Michael Mulroy, a former deputy assistant secretary of defense for the Middle East during Trump's first term.
Under former President Joe Biden, the United States launched air strikes against Ansar Allah targets, claiming the operations were aimed at keeping the Red Sea trade route open. Trump intensified US bombing operations last year after Ansar Allah targeted US warships and commercial vessels off Yemen's coast.
Experts believe neither campaign eliminated Ansar Allah's ability to threaten shipping.
Last year's two-month US operation required significant military resources, including two aircraft carriers, additional warships, fighter jets, and strategic aircraft such as B-2 bombers.
A renewed campaign could therefore place further pressure on US military resources at a time when many of the same assets are already committed to the war against Iran.
Although the US military is the world's most-funded armed force, officials acknowledge that its resources are not unlimited.
Many of the systems that could be needed for attacks around Yemen are currently being used in the war against Iran, while prolonged deployments are placing additional strain on American personnel and equipment.
"We're pretty busy already", one official said, noting that some US warships have remained at sea longer than usual amid the intense operational tempo.
Extended deployments increase pressure on service members, while warships eventually have to return to port for maintenance.
More than 20 US Navy warships and hundreds of US military aircraft are currently operatingin the region. Additional forces are also being deployed to the region to support the US war against Iran, according to a second US official.
That could limit Washington's ability to respond to a potential escalation near Yemen, which officials say would require significant naval and air assets.
A new confrontation could also divert US intelligence resources toward tracking Ansar Allah's military capabilities, which may have evolved since last year's offensive.
Mark Cancian, a retired US Marine officer at the Center for Strategic and International Studies, agreed that another front in the Red Sea would further stretch US naval forces.
The prospect of sustained operations could also intensify pressure on American stocks of munitions and air defense interceptors, which experts have warned are already facing increased demand amid the war against Iran.