Houthi strikes on Saudi Arabia show the Yemeni rebels' growing strength

Yemen's Iran-backed Houthi rebels have put their growing military capabilities on display in recent weeks, repeatedly striking Saudi Arabia's main international airport hundreds of miles (kilometers) away and seizing territory inside Yemen near a key shipping chokepoint.

At various times over the last decade, Saudi Arabia, the United Arab Emirates, the United States, Britain and Israel have carried out punishing air raids on the rebels — only to see them grow even stronger.

The Saudis have struggled to counter the latest attacks, even with far superior U.S.-supplied arms. A senior Saudi diplomat told reporters this week that Iran was encouraging the escalation and that over the summer the Houthis had spurned an offer to negotiate.

The Houthis operate in a large and mountainous territory where they can disperse fighters and military infrastructure while threatening major oil facilities and key trade routes.

Iran and its allies in Lebanon and Iraq provide expertise, training and sophisticated weapons, according to U.N. and other experts. A recent report found that the Houthis have tried to source parts from Chinese suppliers that are used to make precision-guided ballistic missiles with a range of roughly 1,200 miles (2,000 kilometers).

The Houthis already have a wide array of ballistic missiles, cruise missiles and drones — many resembling Iranian models — that can reach all the Gulf states as well as Israel. They have also used sophisticated anti-ship missiles and naval drones to strike vessels in the Red Sea, threatening a critical trade route.

Iran denies arming the Houthis, which would violate a U.N. embargo. China has not directly responded to the latest report but says it has a “prudent and responsible” approach to military exports.

Smuggled Iranian weapons and parts have been seized from numerous Yemen-bound shipments, and a report by U.N. experts in 2024 documented extensive military ties between the Houthis, Iran and its other allies.

That report estimated that the Houthis had recruited up to 350,000 fighters by 2024, up from just 30,000 in 2015, when Saudi Arabia intervened in Yemen's civil war against the Houthis and imposed a naval blockade.

The Houthis can use relatively inexpensive drones and missiles to target oil and other infrastructure just across the border in Saudi Arabia, as well as tankers off the coast. And while Iran is believed to supply cutting-edge components like guidance systems, the Houthis can manufacture much of their weaponry domestically, and at a much lower cost than the state-of-the-art interceptors used by the Saudis.

There are suggestions they may even be using artificial intelligence to try to build better missiles.

Saudi Arabia boasts an array of U.S.-supplied weapons, including sophisticated aircraft as well as advanced missile defenses used against Iran at the height of the war last spring.

But with supplies of high-end interceptors under pressure, it's unclear how long it can ward off attacks — not only from the Houthis, but from Iran-backed militias in Iraq blamed for an attack that briefly shut down an east-west pipeline crucial for oil exports.

In recent days, the Houthis have repeatedly struck King Khalid International Airport in the capital, Riyadh, leading to a wave of flight cancellations. They have also hit the headquarters of the national oil company, Aramco. Both are several hundred miles (kilometers) from Yemen.

At least 19 people have been killed, school classes have been canceled, and the disruption threatens the kingdom's ambitious plans to transform itself into a global hub for business, tourism and sports.

Vulnerable assets are scattered across Saudi Arabia’s sparsely populated territory, which is roughly three times the size of Texas. Its border with Yemen stretches more than 1,300 kilometers (800 miles) through rugged desert areas.

The Houthis, a Shiite religious and political movement rooted in northern Yemen, are attacking Saudi Arabia because it supports Yemen's internationally recognized government in the civil war.

The Sunni kingdom, which has long feared the emergence of a well-armed ally of Shiite Iran on its border, joined the war in 2015 after the rebels seized much of northern Yemen, including the capital, Sanaa.

Over the next seven years, Saudi Arabia carried out waves of airstrikes against the Houthis, often killing civilians. An array of Yemeni government forces and southern separatists struggled to push the Houthis back, and the battle lines moved little before a 2022 ceasefire.

The following year, after the outbreak of the war in Gaza, the Houthis began attacking Red Sea shipping in what they said was a blockade of Israel. The U.S. and the U.K. launched waves of strikes against the Houthis beginning in January 2024.

U.S. President Donald Trump ordered an intensified air campaign early last year, with some 2,000 munitions dropped on over 1,000 targets, a U.S. military official told The Associated Press at the time.

After weeks of U.S. strikes, the Houthis agreed to stop attacking American ships. But they continued to target Israel, which responded with its own strikes later in 2025, killing the Houthi prime minister along with other senior officials and repeatedly hitting a key port.

The Houthis largely kept to the sidelines in the first several months of the Iran war, but in July, they resumed attacks on Saudi Arabia and declared a blockade on Saudi shipping.

As recent conflicts have shown, air power is rarely effective without ground troops who can move in and seize territory after strikes.

In the case of Yemen, the ground fighters inside the country who are taking on the Houthis are deeply divided and fought each other as recently as January. They include fighters loyal to the Saudi-backed government and southern separatists supported by the United Arab Emirates — a sometimes rival to the Saudis that withdrew from Yemen in 2019.

The U.S., still preoccupied with Iran, appears keen to stay out. The Saudis signed a mutual defense pact with nuclear-armed Pakistan and NATO member Turkey in August, but it's unclear what kind of assistance they are prepared to provide.

The diplomatic options are also limited. The Houthis are demanding that Saudi Arabia lift its blockade, which would be an admission of defeat in the long-running war and pave the way for even more extensive Iranian aid to the rebels.