Anthropic says Claude users in northern Yemen, a territory controlled by the Iranian-backed Houthi rebelstried to use the AI model to develop advanced missiles.
AI has already transformed military operations from Ukraine to Gaza, and its use on a harsh and remote battlefield is likely to heighten concerns about its rapid spread.
Anthropic said the users of the accounts it blocked after identifying them had not been able to “get a working device in,” but had conducted a failed test of a guided missile. He said he knows this because users have gone back to his Claude chatbot to find out why it failed.
In a report released Thursday, the company did not identify the users. But Yemen’s mountainous north is controlled by the Houthis, suggesting the rebels are pursuing more sophisticated weapons at a time when they already have an array of drones, missiles and other munitions in their campaign to seize more territory in Yemen and damage Saudi oil exports.
Hazam al-Assad, a member of the Houthis’ politburo, said it was “unwise and illogical” for them to rely on open sources to develop and produce military capabilities.
“Our armed forces have modern, diverse and advanced production capabilities and technologies that they have accumulated during the period of Saudi aggression against Yemen,” al-Assad said, referring to the kingdom’s involvement in Yemen’s 12-year civil war. He said all guns are used for self-defense.
The report is the third published by Anthropic since March 2025 on the global abuse of its AI platforms and details findings from December to August, ranging from state-sponsored groups spreading propaganda to unnamed actors researching how to make biological weapons more lethal.
The Houthis may have wanted to develop their abilities
The developer of the popular chatbot Claude said he had identified a cell in northern Yemen pursuing three different weapons programs, including a multi-range missile that glides at hypersonic speeds and a warhead that uses cellphone hardware to maneuver mid-course.
It said actors in Yemen used Claude Code instead of human software engineers to develop guidance, navigation and control software. Multi-variable missiles are those where different warheads and guidance systems can be mounted on the same basic structure, a more economical way to build land, sea and air weapons.
Anthropic said it had evidence that before the accounts were banned, users had already created an offline simulation toolkit that did not use Claude or other computing platforms.
Trevor Ball, a weapons analyst at Armament Research Services, said that while the Houthis “may be looking at hypersonic (missiles) by asking Claude,” they don’t even have the manufacturing or technical capabilities to build them. He noted that US hypersonic missiles are “still being tested”.
He said the Houthis already have Iranian-made anti-ship missiles with systems that allow the missiles to correct their guidance mid-course.
“They are probably just trying to develop their own capabilities more so they are less dependent on Iranian supplies of weapons and components,” he said in a text message.
Iran has boasted that it has hypersonic missiles and claims to have fired them at Israel last year. It denies arming the Houthis, which would violate a UN embargo, but Iranian weapons have been found on the battlefield and seized from shipments bound for Yemen.
The Houthis are increasingly threatening key sea routes
The Houthis have launched waves of attacks on Saudi oil facilities and tankers in the Red Sea, threatening global trade as Iran continues to disrupt shipping in the Strait of Hormuz.
Rebels have made lightning territorial gains since Wednesday in their war with Yemen’s Saudi-backed government, seizing strategic territory along the Red Sea coast and in the Bab al-Mandeb Strait, a key alternative to the Strait of Hormuz.
Adam Baron, a Yemen-focused researcher at the New America think tank in Washington, said the Houthis are keeping pace with technological developments.
“There’s a tendency to see the Houthis as this group of barefoot tribal fighters, and that’s just not true,” he said. “Whether it’s things like their new use of Claude, their use and manipulation of social media narratives, or their ability to benefit from the transfer of Iranian and wider expertise, we’re talking about an incredible — and deepening — amount of institutional technical knowledge.”
The Houthis are known to have acquired and developed a sophisticated arsenal of weapons, including Iranian-made cruise and ballistic missiles with a range of more than 2,000 kilometers (1,200 miles) and unmanned submarines used in attacks.
Anthropic said it has shared its findings with private and public partners.
Connected: Anthropic says Russian hackers used Claude AI to automate malware evasion
