For years, the Iranian-backed Yemeni rebels known as the Houthis were so good at harassing America's partners in the Middle East that Pentagon war planners began copying some of their tactics.
A senior U.S. commander noted that the Houthis had managed to weaponize commercial radar systems commonly available in boat shops and make them more portable, and urged his Marines to figure out something similar. By September 2022, Marines in the Baltic Sea adapted Houthi-style mobile radar systems.
Therefore, once the Houthis began attacking ships in the Red Sea, senior Pentagon officials knew they would be difficult to tame.
As the Biden administration approaches its third week of airstrikes against Houthi targets in Yemen, the Pentagon is trying to thread an incredibly small needle: limiting the Houthis' ability to attack merchant ships and naval vessels without drawing the United States into a prolonged war pull .
It's a difficult task, made all the more difficult as the Houthis have perfected irregular warfare tactics, American military officials say. The group doesn't have many large weapons depots for American warplanes to bomb – Houthi fighters are constantly on the move with rockets, which they fire from pickup trucks on remote beaches before running away.
The first barrage of American airstrikes hit nearly 30 locations in Yemen nearly two weeks ago, destroying about 90 percent of the targets attacked, Pentagon officials said. But despite this high success rate, the Houthis retained about 75 percent of their ability to fire missiles and drones at ships transiting the Red Sea, these officials admitted.
Since then, the Pentagon has carried out several more rounds of attacks. And the Houthis have continued their attacks on ships transiting the Red Sea.
“There is a level of sophistication here that cannot be ignored,” said Gen. Joseph L. Votel, who led the U.S. military’s Central Command from 2016 to 2019 when Saudi Arabia tried to defeat the Houthis in Yemen.
The Pentagon's strategy so far has been to deploy armed Reaper drones and other surveillance platforms in the skies over Yemen so that U.S. warplanes and ships can strike emerging Houthi mobile targets.
On Monday evening, the US and Britain attacked nine locations in Yemen, hitting multiple targets at each location. Unlike most previous strikes, which were more about attacks of opportunity, the night strikes were planned. They hit radar devices as well as drone and missile sites as well as underground weapons storage bunkers.
This middle ground reflects the government's attempt to frustrate the Houthis' ability to threaten merchant vessels and military vessels, but not to hit them so hard that they kill large numbers of Houthi fighters and commanders, potentially creating even more chaos in the region would trigger.
But officials say they will continue to try to hit mobile targets while analysts look for more fixed targets.
After nearly a decade of Saudi airstrikes, the Houthis have become adept at concealing what they have by placing some of their launchers and weapons in urban areas and firing missiles from the backs of vehicles or tractors before moving away.
And the destroyed weapons will soon be replaced by Iran as a never-ending stream of dhows ferry more weapons into Yemen, U.S. officials say.
Even a seemingly successful American commando operation on Jan. 11 to seize a small boat carrying ballistic and cruise missile components bound for Yemen came at a price: The Pentagon said Sunday that the status of two Navy SEALs who died during the The man who was reported missing in the operation was declared dead after an “extensive” 10-day search. Marine commandos, supported by helicopters and drones hovering overhead, had boarded the small boat and seized propulsion and guidance systems, warheads and other items.
The Houthis are believed to have had underground assembly and production facilities even before Yemen's civil war began in 2014. The militias seized the country's army arsenal when they captured the capital Sana a decade ago. Since then, it has amassed a diverse and increasingly deadly arsenal of cruise missiles, ballistic missiles and disposable attack drones, mostly supplied by Iran, military analysts said.
“The diversity of their arsenal is overwhelming,” said Fabian Hinz, an expert on missiles, drones and the Middle East at the International Institute for Strategic Studies in London.
Hezbollah, the Iranian-backed Lebanese militia, also helped. Senior Houthi commanders primarily learned how to be adaptable from Hezbollah trainers in Lebanon, said Hisham Maqdashi, a defense adviser to Yemen's internationally recognized government.
Hezbollah “trained them to adapt to the changes of the war in Yemen,” Mr. Maqdashi said in an interview. “They didn’t teach them the details, they taught them how to be very dynamic.”
That leaves the United States and its coalition partners with only three viable options given the parameters of President Biden's strategic objectives in Yemen, military analysts say. They could confiscate the weapons coming from Iran by sea; Find the missiles, which requires extensive reconnaissance. or attack the starting positions.
The third option is the most difficult. Houthi fighters are believed to be hiding mobile rocket launchers in various locations, from culverts to highway overpasses. They can be easily moved for quick starts.
The Houthi mobile maneuvers worked so well against Saudi Arabia that the Marines launched an experimental attempt to copy them. They developed a mobile radar, essentially a Simrad Halo24 radar — one can be found for about $3,000 at Bass Pro Shops — that can be mounted on any fishing boat. Setup takes five minutes. The Marines, like the Houthis, have been thinking about how to use the radars to send back data about what's happening at sea.
Lt. Gen. Frank Donovan, now deputy commander of U.S. Special Operations Command, noticed what the Houthis were doing with radar while he was leading a Fifth Fleet amphibious task force in the southern Red Sea. General Donovan attempted to determine how the Houthis were targeting ships and soon realized that the Houthis were attaching commercial radar devices to vehicles on the shore and moving them around.
He asked his Second Light Armored Reconnaissance Battalion to develop a similar system.