Houthis Grow Stronger Despite Years of Airstrikes as They Advance on Key Strait

Over the past decade, Saudi Arabia, the United Arab Emirates, the United States, Britain and Israel have launched repeated air raids on Yemen's Houthi rebels. Each time, the group has emerged stronger. Now, as the Iran-backed Houthis push toward the Bab el-Mandeb — the narrow strait linking the Red Sea to the Gulf of Aden — and strike Saudi oil facilities, there is little left to try that has not already been attempted.

The Houthis' resilience stems partly from geography. They operate across a vast, mountainous territory where fighters and military infrastructure can be dispersed. From there, they can threaten major oil installations and key trade routes. Iran and its allies in Lebanon and Iraq supply expertise, training and sophisticated weapons, according to UN and other experts, while the group's hard-line ideology sustains its fighting capacity.

Michael Knights, head of research at the New York-based advisory Horizon Engage, describes them as the most committed, ideologically pure and aggressive of Iran's regional allies. "Things that took the Lebanese Hezbollah 20 years to develop, the Houthis have developed in five," he said.

The Houthis possess a wide array of ballistic and cruise missiles and drones, many resembling Iranian models, capable of reaching all Gulf states and Israel. They have also used anti-ship missiles and naval drones to strike vessels in the Red Sea, threatening a critical trade corridor.

Iran denies arming the Houthis, which would violate a UN embargo. However, smuggled Iranian weapons and parts have been seized from numerous shipments bound for Yemen, and a 2024 UN expert report documented extensive military ties between the Houthis, Iran and its other allies. That report estimated the Houthis had recruited up to 350,000 fighters by 2024, up from about 30,000 in 2015, when Saudi Arabia intervened in Yemen's civil war 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 offshore. While Iran is believed to supply cutting-edge components such as guidance systems, the Houthis manufacture much of their weaponry domestically.

Saudi Arabia possesses an array of US-supplied weapons, including sophisticated aircraft and advanced missile defenses used against Iran at the height of the war last spring. But with supplies of high-end interceptors under pressure, it is unclear how long it can ward off attacks — not only from the Houthis but also from Iran-backed militias in Iraq blamed for an attack that shut down an east-west pipeline crucial for oil exports.

Saudi Arabia went to war against the Houthis in early 2015, after the rebels seized much of northern and central Yemen, including the capital, Sanaa, from the internationally recognized government. Even then, Riyadh feared the growth of a well-armed Iranian proxy on its border. Over the next seven years, Saudi Arabia carried out waves of airstrikes, often killing civilians. Yemeni government forces and southern separatists struggled to push the Houthis back, and 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 US and UK launched waves of strikes against the Houthis beginning in January 2024. The next year, US President Donald Trump ordered an intensified air campaign, with some 2,000 munitions dropped on over 1,000 targets, a US military official said at the time. The cost of US munitions alone exceeded $750 million, while the Houthis destroyed seven US MQ-9 Reaper drones, each worth more than $30 million. An F/A-18 fighter jet worth over $60 million slid off an aircraft carrier.

After weeks of US strikes, the Houthis agreed to stop attacking American ships but continued to target Israel, which responded with its own strikes later in 2025, killing the Houthi prime minister and other senior officials and repeatedly hitting a key port. The Houthis largely stayed on the sidelines during the first 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 able to seize territory after strikes. In Yemen, anti-Houthi ground forces 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 UAE, a sometimes rival to the Saudis that withdrew from Yemen in 2019.

"Half of the story is Iranian support, and this is extremely important ... but there's another half of the story, which is the weakness of their adversaries," said Thomas Juneau, a professor of international affairs at the University of Ottawa specializing in Iran and Yemen. Yemen's internationally recognized government, he said, is fragmented, weak, disunited and corrupt, and the Houthis have systematically exploited that.

In recent weeks, anti-Houthi forces have fallen back from one position after another as the rebels advanced toward Bab el-Mandeb. The Saudis appear reluctant to enter another full-scale war, which would involve prolonged fighting and high casualties. The US, still preoccupied with Iran, also appears keen to stay out. A Saudi mutual defense pact with Turkey and Pakistan signed last month has yet to be activated.

Diplomatic options are limited. The Houthis are demanding that Saudi Arabia lift its blockade, which would amount to an admission of defeat in the long-running war and pave the way for even more extensive Iranian aid to the rebels. "As long as US-Iran tensions are not resolved, there will not be significant progress between Saudi Arabia and Iran," Juneau said. "The Houthis are in a very intransigent mood right now, and they are absolutely not ready to make any kind of concessions."