Fresh Houthi attacks on Saudi oil and aviation targets have demonstrated the Yemeni movement’s growing military reach. Defence analyst Akram Kharief says the group has transformed its arsenal of drones and missiles since a 2022 ceasefire, building its capacity to produce weapons locally while retaining important technological links to Iran.

A Houthi supporter holds a mock missile during a demonstration in support of Palestinians, in Sanaa, Yemen, 5 April 2024. Houthi rebels are believed to have expanded their weapons-making capacities significantly in recent years. © AP - Osamah Abdulrahman Saudi Arabia said on Thursday it had intercepted and destroyed a Houthi cruise missile over the Medina region, home to one of Islam’s holiest cities – an area the Yemeni movement had previously said it would not target.

The interception came the day after Houthis claimed attacks on Riyadh airport and a Saudi Aramco site, after Saudi authorities reported a strike on a building belonging to the oil giant. The Yemeni rebels have warned that further operations will follow in the coming days.

The attacks testify to the Houthis’ growing military capacities, according to Kharief, a researcher specialising in defence and security with the Washington-based Middle East Institute .

While the rebels originally relied on their main ally Iran for missile components and technology, he says the Houthis are now largely able to manufacture their own weapons.

He told RFI about the group’s increasingly sophisticated arsenal, how it is being stocked and to what extent it might allow the rebels to act independently of Tehran. Western leaders slam Houthi attack on Riyadh airport, warn citizens to stay away RFI: Since this offensive began in September, the Houthis have shown greater military power than during the previous phase of the conflict from 2014 to 2022. Do you see evidence they are gathering strength?

Akram Kharief: Yes, absolutely. Since 2022, the Houthis have significantly modernised their military capabilities, particularly their ballistic missiles, drones and cruise missiles. They now have technologies that are very similar to those used by Iran.

They have made significant progress in range, guidance, accuracy and payload. We are now seeing the results on the ground. Their current capabilities bear absolutely no resemblance to the weapons they were using at the start of the war against Saudi Arabia.

RFI: Is that mainly the result of Iranian support, or have the Houthis made technological advances of their own?

AK: It is a combination of both. We have tangible evidence of technological development carried out locally. A September report by Anthropic , the US company behind the Claude artificial intelligence system, identified a weapons-development cell in Houthi-controlled northern Yemen that had used the tool to work on guidance systems. That demonstrates a genuine capacity for local technological development.

At the same time, the Houthis have benefited from manufacturing plans and certain sensitive components from Iran. They have also drawn on Iran’s operational experience during the different phases of the conflict between Iran and Israel.

This image, taken from undated video released by the media arm of Yemen's Houthi rebels, shows what the group says is a Houthi fighter firing a mortar during clashes with Saudi-backed forces at an undisclosed location in Yemen. © Ansar Allah Media Office via AP Houthi war risks dragging Israel and Turkey into Horn of Africa standoff RFI: How can artificial intelligence be used in missiles?

AK: According to the Anthropic report, Claude’s computing, engineering and programming capabilities were used to develop several types of software. This includes software capable of analysing mapping data and aerial imagery to help a missile navigate and identify its target. AI can also be used to develop image-processing and recognition tools for cameras mounted on drones.

It can also improve the ability of some cruise missiles and drones to distinguish between potential targets – in other words, to identify and select a target autonomously, without necessarily having to communicate with an operator in Yemen before deciding to strike. That represents a considerable advance in the autonomy of weapons systems.

This kind of use is still relatively unusual. We have already seen artificial intelligence being applied to drones in Turkey, Israel and the United States, as well as on the Ukrainian battlefield by both Russia and Ukraine. But it remains a fairly limited field, confined to certain armed forces and weapons manufacturers.

RFI: Is Iran the Houthis’ only military partner, or are they benefitting from other forms of cooperation?

AK: So far, Iran is the only country that has actually transferred technology and know-how to the Houthis. We have not seen them using missiles or drones from sources other than Iran or local production.

However, another factor has to be taken into account – the widespread availability of technology and the dual-use nature of many components, meaning they can have both civilian and military uses. The same electronic components can sometimes be found in a hairdryer and in a small drone. So it is entirely normal to find chips, circuit boards or motors made in China, Japan or South Korea inside missiles and drones used in Yemen and elsewhere.

A large proportion of the components now used in Houthi drone and missile technology do indeed come from China . But that does not mean there is military cooperation with Beijing. This is primarily about civilian technologies being diverted for military purposes, rather than organised technology transfers by China. We see exactly the same phenomenon in the war between Russia and Ukraine. On both sides of the front, drones use practically the same electronic components, many of them manufactured in China. Capture of Mocha marks turning point in Yemen war, with ripples across Red Sea RFI: Is it fair to say that the Houthis are now at least partly independent of Iran?

AK: They are now virtually independent when it comes to production, including from Iran. Most of the raw materials needed to manufacture their weapons are available on the international market. Only a few sensitive components still need to be imported.

Numerous shipments from Iran have been seized in recent years. Some contained hundreds of missile guidance units. These pieces of equipment are only a few centimetres in size, which means a single shipment can provide enough components to manufacture dozens of missiles.

It is also important to remember that transfers from Iran to Yemen have been taking place for around 15 years. The Houthis have therefore had time not only to build up stocks, but also to acquire the skills needed to manufacture a large proportion of their weapons themselves.

This undated photograph released by the US military shows what is described as Iranian-made missile components bound for Yemen's Houthi seized off a vessel in the Arabian Sea. © AP - US Central Command Most of the technology nevertheless remains Iranian in origin. Take the Houthis’ “Palestine” missile, for example, which is a copy of Iranian Fattah medium-range ballistic missiles. Although nearly 90 percent of it is manufactured in Yemen, its guidance system, certain sensitive components and the plans needed to build it come from Iran.

The Houthis have therefore achieved a high degree of industrial autonomy while remaining technologically dependent on Tehran. This local production capacity poses a major problem for the future of the conflict because their facilities are often spread across small workshops or underground factories, sometimes buried deep in the mountains, making them particularly difficult to locate and destroy.

RFI: Does that mean the Houthis are not simply Iranian “proxies”, as they have sometimes been characterised?

AK: No. I believe the Houthis have a very high degree of political autonomy from Iran, particularly when it comes to deciding whether or not to go to war. We saw that during their involvement against Israel in the Iran-Israel war earlier this year. Their participation came down to their own choices – they decided when to strike and when to hold back. They also did not systematically follow Iranian instructions, particularly over the ceasefire.

It is important to understand that the Houthis’ actions against Israel also served their own strategic objectives, which were already focused on Saudi Arabia. They were anticipating a large-scale conflict with Riyadh and were already working to weaken Saudi defence capabilities. Their military engagement was therefore not simply about serving Iranian interests – it was also based on their own calculations.

Today, the political interests of Iran and the Houthis certainly align, but it would be wrong to conclude that Tehran has absolute control over their decisions. It is difficult to imagine that the Iranians could simply snap their fingers and limit or end Houthi military operations. Video: Who are Yemen's Houthis?

RFI: The Saudi military appears to be struggling to deal with Houthi attacks. Is that because Riyadh is showing restraint, or does it reflect military weakness?

AK: I do not believe there is any genuine desire for restraint on the Saudi side. The Saudis have, for example, bombed Sanaa airport 19 times in recent years. Saudi Arabia’s main problem in Yemen is the shortage of clearly identified and visible military targets.

The Houthis have buried much of their weaponry, military infrastructure and command posts in mountainous areas that are particularly difficult to bomb. The Saudis are also keen to avoid losing aircraft, so they limit low-altitude operations. That considerably reduces the effectiveness of air strikes and forces them to consider ground operations.

But we should not conclude from this that Saudi Arabia is incapable of intercepting missiles and drones launched from Yemen. I would estimate that its interception rate is around 90 percent.

The real problem is the remaining 10 percent. Projectiles that make it through Saudi defences can cause considerable damage to highly sensitive infrastructure that is difficult to replace and carries enormous symbolic value.

This article has been adapted from an original interview by RFI's Oriane Verdier and lightly edited for clarity.