Sophia Yan received the 2020 Marie Colvin Award for her coverage of China, where she was previously based for a decade. Her investigations have exposed human trafficking, illicit weapons transfers, war crimes, terrorist financing, and militant networks. Her reporting has contributed to international sanctions, asset freezes, and law enforcement investigations.

5:26pm BST China is supporting the Iran-backed Houthis as a way to pressure the US.

The militant group is seeking to build a medium-range ballistic missile that, according to a research report, would be made with Chinese components.

The Houthis are seeking to manufacture domestically at least part of the Iranian Khaibar Shekan series of ballistic missiles, which have a range of more than 1,000 km (620 miles), according to Conflict Armament Research, a UK-based investigative organisation that tracks the use of weapons in conflict zones.

The research group has identified custom-made missile components, as well as raw materials, tools and testing equipment, in recent shipments intended for the Houthis, and has also found these components alongside shipping documents that list a Chinese supplier.

The Houthis have increasingly sought to boost domestic production, but these latest revelations suggest a significant leap in their abilities, as only a few countries in the world have the expertise to produce missiles with such range. This also suggests an increasing independence from Iran, their main backer.

Shahab-3, left, and Khaibar-buster missiles displayed during the annual Jerusalem Day rally in Tehran The findings come from shipments interdicted by authorities in Yemen, where the Houthis are based and control large swaths of territory.

In fact, Chinese companies are now the largest source of goods seized from shipments bound for the Houthis, according to United Nations reports and research by arms experts.

China has publicly called for peace in the Middle East and north Africa, even going so far as to lobby Iran to pressure the Houthis to back down from attacks in the Red Sea, a key waterway for global trade, similar to the Strait of Hormuz.

At the same time, China is supplying the Houthis with dual-use goods that have both military and civilian purposes – a similar approach to how Beijing has materially supported Russia’s invasion of Ukraine by sending components and machine tools to make weapons.

This approach provides Beijing with plausible deniability, as it can say that it is merely part of regular commercial trade.

Chinese support comes in addition to Iranian backing for the Houthis, which has largely been focused on providing intelligence, strategy and training, and sending finished weapons. China, too, has supported Iran by sending drone components and rocket-fuel precursors, and by buying sanctioned oil.

Wreckage of a vehicle in a location given as Marib Governorate, Yemen, after what Houthi Military Media said was the targeting of government forces’ armoured vehicles All this has helped Iran to stay afloat, and underpins the regime’s ability to support its proxy groups, which brings the relationship full circle with the Chinese separately supporting Iran’s non-state actors, such as the Houthis.

“Chinese support for the Houthis is best understood as a combination of diplomatic protection, selective enforcement, and strategic opportunism,” said Mohammad al-Basha, founder of the Basha Report, a US-based risk advisory.

“China appears willing to turn a blind eye to the Houthis’ use of Chinese commercial artificial-intelligence technologies, satellite services provided by companies with reported links to the Chinese government, and the continued flow of dual-use equipment into Yemen.”These goods include precision machine tools to manufacture weapons, large quantities of fertiliser that could be used in missile propellants, specialised metals for missile components, and electronics used in drone production, he noted.

Experts say the Houthis have boosted ties with the Chinese over recent years, building upon the relationships that longtime Yemeni traders have in China. The militant group has also chosen members to learn Mandarin in an effort to improve relations.

In return, China has secured promises from the Houthis for Chinese commercial shipping vessels to transit safely, which is important for the continued economic health of the world’s largest exporter.

Houthi supporters ride in a truck carrying the coffin of a fighter who was recently killed in conflict, during a funeral procession in Sana’a on Saturday It also allows Beijing to preserve a potentially useful relationship with the Houthis, an armed group that could prove useful if China were to invade Taiwan, an island nation that Beijing claims as its territory.

The Houthis, for instance, could threaten one of the world’s most important maritime corridors and divert US naval assets and resources away from the Indo-Pacific region, making it difficult for the US to send military assistance.

But China is playing with fire when it comes to the Houthis. While Beijing enjoys safe passage through the Red Sea for now in exchange for its support for the Houthis, that may not hold forever.

Still, the greater concern is to remain in opposition to the US. China cannot risk any perception of being on side with the US. Thus, Beijing must continue putting up resistance against Washington.

China’s activities must be “understood within the broader context of great power competition”, said Mr Basha.

“For Beijing, the Houthis could represent a relatively inexpensive means of exerting indirect pressure on the US and its regional partners without committing Chinese military forces or openly confronting Washington.

“Much like its relationship with Iran, China can potentially gain strategic leverage while limiting its direct exposure and costs.”