Saudi Arabia is turning to foreign allies to fend off Houthi missiles and drones, exposing a military vulnerability that could soon become President Donald Trump's problem.

Britain announced Tuesday it would send Typhoon fighter jets to defend Saudi cities and critical infrastructure, Egypt is already assisting the kingdom and Israel has offered to step-in to help.

Riyadh, meanwhile, is asking Washington for more interceptors, and Trump is weighing whether the U.S. should intervene and strike the Iran-backed Houthis directly.

The reinforcements could help shield Saudi cities and critical infrastructure. They do little, however, to eliminate the Houthi launchers and weapons threatening them from Yemen.

"The theme right now, I think, is defensive or defensive-minded," Jason Campbell, a senior fellow at the Middle East Institute, told Fox News Digital.

The question, he said, is whether that evolves into something "more offensive or kinetic." The Houthis have already demonstrated their ability to punch through Saudi defenses. Their strikes and attempted strikes on the kingdom more than doubled in a single week this month, according to the Armed Conflict Location & Event Data Project, with airports in Riyadh, Jizan, Najran, Dammam and Abha targeted since Oct. 5.

The most devastating barrage struck King Khalid International Airport in Riyadh, killing at least 13 people and wounding more than 300.

Other attacks have targeted Saudi energy infrastructure, turning the Houthi campaign into a threat not only to the kingdom's security but also to the economic stability Riyadh has spent years trying to project.

Saudi Arabia has spent decades building one of the region's most sophisticated militaries. Riyadh spent an estimated $83.2 billion on defense last year, making it the eighth-largest military spender in the world, according to the Stockholm International Peace Research Institute. Its arsenal includes U.S.-made F-15 fighter jets, Patriot missile defenses and advanced radar systems.

Yet the Houthis are exploiting a mismatch between the defenses Saudi Arabia and its partners spent years building and the weapons now coming at them.

Campbell said the U.S. and its regional partners had been comparatively well prepared to confront the higher end of Iran's arsenal, including ballistic missiles and other advanced weapons.

"What the region was decidedly less prepared for was an array of lower end of the spectrum ... threats posed by Iran and now the Houthis," Campbell said.

The volume is part of the problem. Campbell said Saudi Arabia and other U.S. partners have burned through significant numbers of high-end interceptors against ballistic missiles and other threats, while lower-flying weapons can also challenge radar and early-warning systems that were not necessarily designed or calibrated to detect them.

Secretary of State Marco Rubio said Tuesday that Riyadh is competing with allies around the world — and the U.S. military itself — for a limited supply of the interceptors needed to defend against missile attacks. "I also talked to Saudi Arabia today; they’d like interceptors.

Israel would like interceptors. We would like interceptors. Every country in the world would like interceptors," Rubio said, calling them "probably the most in-demand product right now in the defense field." The U.S. cannot meet every request, Rubio acknowledged. American forces must maintain minimum air-defense requirements at bases around the world, while the sophisticated interceptors are expensive and take time to manufacture even as production increases. "We have our own needs too," Rubio said.

Saudi Arabia's sheer size compounds the challenge. The kingdom stretches across more than 800,000 square miles, leaving cities, airports, oil facilities and military installations spread across a vast territory.

"Saudi Arabia is a huge geography to protect, and this speaks to a larger threat we’re facing globally: a relatively small nonstate actor can pose a serious challenge to even a sophisticated and extremely expensive military," Farea Al-Muslimi, a research fellow at Chatham House, told Fox News Digital. "The Houthis can impose enormous costs without having to spend very much themselves." That imbalance helps explain why Saudi Arabia is increasingly looking beyond its own military for protection. But outside assistance may have limits.

"Many years later, everyone is realizing that the Houthis are not just Saudi Arabia’s problem, but everyone’s problem — whether that’s Turkey, Egypt, France, the UK or others," Al-Muslimi said. "But I don’t think this outside support will make a significant military difference unless the U.S. is directly involved." That leaves Trump facing a potentially consequential decision: whether to continue helping Saudi Arabia defend against incoming attacks or go further and target the Houthis directly.

Trump has kept direct U.S. military action on the table. Asked earlier this month whether the U.S. could join Saudi strikes against the Houthis, he said, "We may. We’re gonna look at it."

"We’ll make a decision," Trump said. "We move very quickly." But direct U.S. intervention would not be without precedent — or questions about what another bombing campaign could accomplish.

Operation Rough Rider targeted Houthi positions across Yemen for roughly two months in 2025 before Trump halted the operation after Oman brokered an agreement with the group.

"We’ve already seen the U.S. conduct a 60-day bombing campaign of Houthi strongholds in Yemen with limited, if any, real strategic benefits," Campbell said.

A new campaign would also compete for U.S. military resources amid the war with Iran. Campbell said taking on the Houthis would require clearer objectives and likely contributions from a broader coalition.

Israel has also offered to help defend Saudi Arabia, an offer Trump has publicly encouraged Riyadh to accept. But bringing Israel openly into the fight could create a different problem for the kingdom.

"If I were Saudi, I would never accept help like that," Al-Muslimi said. "The optics are enormously difficult. Saudi Arabia is the custodian of the two holiest mosques in Islam, and appearing alongside Netanyahu to fight another Yemeni group would be a nonstarter for much of Saudi society." For now, the U.S. continues to provide intelligence and targeting support to Saudi Arabia as its allies focus on defending the kingdom. "The collective effort seems to be at stemming the threat to the Saudi kingdom itself," Campbell said.

But as Al-Muslimi cautioned, even a stronger defensive coalition may not eliminate the danger.

"It can make Saudi Arabia safer, but it doesn’t solve the larger problem of dismantling the Houthi threat." The latest fighting is another chapter in a war that has torn through Yemen for more than a decade. The Houthis seized the capital, Sanaa, in 2014, prompting Saudi Arabia to lead a military intervention the following year against the Iran-backed group and in support of Yemen's internationally recognized government.

Years of Saudi airstrikes failed to dislodge the Houthis, while the group steadily expanded its missile and drone capabilities with support from Tehran. The conflict eventually settled into an uneasy truce before erupting again this year, with Saudi-backed forces fighting Houthi advances on the ground and the Houthis increasingly taking the war across the border into Saudi Arabia.

Yemeni civilians are again bearing much of the cost. More than 250,000 people have fled the renewed fighting, according to the United Nations. WHO recorded at least 674 deaths and nearly 3,000 injuries in just six weeks of fighting between August and September, while millions were already facing severe hunger and displacement after more than a decade of war.