Houthi rebels
© Thomson Reuters
A member of a special force loyal to the Houthi rebels riding atop a vehicle during a military parade in Sanaa, Yemen.
In late November, a missile fired by Iran-backed Houthi militants in Yemen came streaking through the sky toward the airport in Saudi Arabia's capital, Riyadh.

The Saudis spotted the incoming fire and shot off five missile interceptors from a US-supplied missile defense system to stop the threat, they say.

"Our system knocked the missile out of the air," US President Donald Trump later said of the incident. "That's how good we are. Nobody makes what we make, and now we're selling it all over the world."

But a new analysis by The New York Times suggests that the missile's failure to hit its target was a fluke and that the missile interceptors all missed.

Essentially, the analysis says that the parts of the Houthi-fired missile that crashed in Saudi Arabia indicate that the interceptors, fired from a Patriot Advanced Capability 3 system, did not hit the warhead as they were supposed to.

Instead, an interceptor probably hit a part of the missile tube that had detached from the warhead, The Times found. The warhead most likely continued to travel, unimpeded, to where it blew up outside the airport. Witnesses reported hearing the explosion, and satellite imagery uncovered by The Times suggests that emergency vehicles responded to the blast.

The missile, an old Scud variant, can be expected to miss by about a kilometer. The Scuds are old and error-prone, and the older ones used by the Houthis are relatively cheap.
Japan Self-Defence Forces Patriot Advanced Capability 3 land-to-air missiles

But the missile defense system developed by the US costs a few million dollars and has been touted by defense officials as one of the most advanced in the world.

In South Korea, the same missile defense systems and technologies are designed to defend US troops and thousands of civilians from a North Korean missile strike.

"You shoot five times at this missile and they all miss? That's shocking," Laura Grego, a missile expert at the Union of Concerned Scientists, told The Times. "That's shocking because this system is supposed to work."

Houthis in Yemen have fired missiles at Saudi Arabia before, and over the weekend they said they fired a cruise missile at a nuclear-energy site in Abu Dhabi, United Arab Emirates - something the UAE has denied.

Footage purportedly of the cruise missile shows that it closely resembles Iranian missiles, suggesting Tehran supplied it. Iran has also been accused of providing the missile fired at the Riyadh airport.

A failure of the missile defenses against even a short-range missile like the one the Houthis fired at the airport may sow doubt about whether the US systems can be trusted to deter conflict in the Middle East, where military tensions have escalated.