Sanaa:
Yemen's Iran-backed Houthis have built up a missile and drone arsenal that allows them varied and sustained strike capabilities, as Saudi Arabia and the Yemeni government it sponsors are finding out.
'Tit For Tat' Strategy
Since early September, the Houthis have hit key oil infrastructure and airports across Saudi Arabia -- notably Riyadh's airport which has been targeted 20 times.
They have also, unsuccessfully, targeted the cities of Medina and Mecca.
The trigger for their return to hostilities, after a four-year truce, was a Saudi bombardment of the airport at Sanaa, Yemen's capital, in July, to prevent a Houthi delegation landing there.
Since then, there have been "tit-for-tat" military strikes, said April Longley Alley, a specialist on Yemen at the Washington Institute think tank.
"The Houthis framed this campaign as blockade for blockade, airport for airport, escalation for escalation," she said.
Varied Arsenal
The Houthis possess a large range of ballistic missiles and drones which they are using to also hit targets in the Bab al-Mandab Strait at the entrance to the Red Sea.
The group's missile stocks partly come from arsenals seized when it took Yemen's capital Sanaa in 2014, as well as "whole systems smuggled in, or self-manufactured systems built from parts that were themselves smuggled into Yemen, primarily via the Arabian Sea", explained Niranjan BS, a strategic weapons analyst at Jane's, the open-source intelligence company.
According to the International Institute for Strategic Studies' Military Balance database, the Houthis have several types of medium-range missiles, several of them derived from Iranian models, such as the Kheibar Shekan.
They also have short-range missiles, such as the Asef anti-ship missile derived from Iran's Khalij Fars class of missile, noted the Wilson Center think tank.
In addition, the Houthis also have a range of cruise missiles from Iran's family of Quds missiles, of which the version 4 is believed to have a range of 2,000 kilometres (1,200 miles), according to the Wilson Center.
They also have a range of drones, both air and maritime, at least some of which were derived from Iranian models.
The Waeid-1 and Waeid-2 aerial drones, for example, are "local copies of the Iranian Shahed-131 and Shahed-136 one-way attack UAVs (unmanned aerial vehicles) respectively," the analyst Niranjan BS said.
Iran's Support
"Iran has provided critical military assistance to the Houthis, particularly with the delivery of missiles and unmanned aerial vehicle (UAV) systems," the Middle East Institute said in a report.
"Missile and UAV parts are designed and manufactured in Iran and smuggled into Yemen via small boats, container ships, or over the Oman-Yemen border, where they are assembled," it said.
However an Israeli analyst specialised in Iran, Danny Citrinowicz, cautioned that the Houthis "see themselves as partners of Iran, not proxies. This is why when people are saying Iran instructed the Houthis, it's not working like that."
"The Iranians have a strong presence in Yemen," set up by the Quds Force, the foreign operations arm of Iran's Islamic Revolutionary Guard Corps, he said at a recent conference in Paris.
But those operatives only advise, they don't decide Houthi operations, he said.
In June 2024, the US Treasury imposed sanctions on a man in China suspected of links to the Houthis, who it said played "a key role in procuring materials that enable Houthi forces to manufacture advanced conventional weapons inside Yemen".
Able To Endure
Having already weathered years of conflict, the Houthis are seen as capable of using their arsenal for a long time to come.
"We need to remember with the Houthis that they have withstood punishing air campaigns before, from the Saudis, from the Americans, and from the Israelis," said the Washington Institute's Longley Alley.
"This is a battle-hardened group, and they have much less to lose than the Saudis."
She added that "The Houthis are probably calculating that they can go longer because they're used to absorbing these strikes".
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)