Why Houthi Missiles Slip Through Saudi Arabia's Air Defences

When the night sky over Riyadh’s King Khalid International Airport lit up with the roar of missiles last Saturday, the world’s attention snapped back to a conflict that has been simmering for more than a decade. Twelve people died, more than three hundred were wounded and the airport—usually a bustling hub—was forced to shut down. It was a stark reminder that even the most sophisticated defence networks can be out‑flanked.

Saudi Arabia, for all its wealth and military spending, relies on a layered shield made up of Patriot batteries, THAAD systems and a host of radar stations spread across its vast territory. In theory, that should be enough to stop anything coming from across the border in Yemen. In practice, the Houthi rebels—who call themselves Ansar Allah, “Supporters of God”—have found ways to poke holes in that shield.

First, it helps to understand what the Houthis are actually firing. Since they seized Sanaa in 2014, the group has moved from crude, short‑range rockets to a mixed arsenal that includes medium‑range ballistic missiles such as the Palestine‑2 and the Iranian‑derived Toufan. Both can travel 1,500‑2,000 kilometres and some versions even carry hypersonic warheads. They also field a plethora of smaller, “budget” missiles—Burkan and Badr series—that are easier to hide and can be launched in quick succession.

What’s more, the Houthis have become adept at combining missiles with loitering drones and cruise‑missile‑style weapons. By sending a slow‑moving drone alongside a faster ballistic missile, they force the Saudi radar operators to make split‑second decisions about which threat to chase first. The result is often a missed interception, not because the technology fails, but because it is overwhelmed by a clever mix of speed and altitude.

“You can build a multi‑layered system, but you’ll always have a few that slip through,” explains Nawaf Obaid, a senior fellow at King’s College London. “Saudi Arabia is a huge country, and its border with Yemen is porous. Expect some penetrations.” He points out that for every missile that reaches a Saudi target, dozens are shot down.

The other side of the equation is supply. Most of the Houthi missiles trace their lineage back to Iran, with occasional Chinese components peppered in. While the group is not a major weapons manufacturer, it has shown a knack for adapting imported technology to its own needs—often by repurposing older Iranian designs and adding crude guidance systems of its own. The United Nations arms embargo and a Saudi‑led blockade make imports difficult, but the rebels have still managed to keep a steady flow of rockets and drones.

Saudi air‑defence planners, on the other hand, have traditionally focused on a different threat: Iranian long‑range missiles aimed at the kingdom’s critical infrastructure. As Wolfgang Pusztai, a defence analyst, notes, “The ballistic‑missile shield was tuned for Iran, not for a guerrilla force that fires in waves from a neighbouring hill.” When the Houthis stepped up their attacks in September, Riyadh had to scramble—literally—to re‑orient its interceptors toward the southern front.

There is also the matter of ammunition. Patriot and THAAD interceptors are not endless; each shot costs millions of dollars. After the early months of the Iran‑Israel conflict, U.S. and allied stocks ran thin, leaving Saudi forces with fewer rounds to spare. Reports suggest Riyadh has been quietly asking allies for extra missiles or even spare air‑defence batteries to plug the gaps.

All this does not mean the Saudis are defenseless. Their radar and missile networks still knock down the vast majority of incoming projectiles. The few that get through tend to be the result of timing, mixed‑payload tactics and the sheer volume of launches the Houthis can muster in a short burst.

For the Houthis, each successful strike is a propaganda win. They can claim they have reached “the heart of the kingdom,” a line that resonates both domestically and with their backers. Yet the group faces its own constraints: a UN‑mandated arms embargo, a crippling blockade and a demanding ground war on multiple fronts. Their missile stockpiles are finite, and every launch depletes resources that could be used elsewhere.

In the end, the recent attacks underscore a simple truth about modern warfare: technology alone does not guarantee safety. Even the most advanced, multilayered shield can be out‑maneuvered by an opponent who knows how to mix speed, altitude and surprise. As the conflict drags on, Saudi Arabia will likely keep tweaking its defences, while the Houthis will continue to look for any opening—no matter how small—to send another missile across the desert sky.