The US military reportedly used Claude, Anthropic’s AI model, to inform its attack on Iran despite Donald Trump’s decision, announced hours earlier, to sever all ties with the company and its artificial intelligence tools.

The use of Claude during the massive joint US-Israel bombardment of Iran that began on Saturday was reported by the Wall Street Journal and Axios. It underlines the complexity of the US military withdrawing powerful AI tools from its missions when the technology is already intricately embedded in operations.

According to the Journal, US military command used the tools for intelligence purposes, as well as to help select targets and carry out battlefield simulations.

On Friday, just hours before the Iran attack began, Trump ordered all federal agencies to stop using Claude immediately. He denounced Anthropic on Truth Social as a “Radical Left AI company run by people who have no idea what the real World is all about”.

The flaming row was triggered by the use of Claude by the US military in its raid to capture the president of Venezuela, Nicolás Maduro, in January. Anthropic objected, pointing to its terms of use which do not allow Claude to be applied for violent ends, to develop weapons, or for surveillance.

Since then relations between Trump, the Pentagon and the AI company have steadily worsened. In a lengthy post on X on Friday, the defense secretary Pete Hegseth accused Anthropic of “arrogance and betrayal”, adding that “America’s warfighters will never be held hostage by the ideological whims of Big Tech”.

Hegseth demanded full and unrestricted access to all Anthropic’s AI models for every lawful purpose.

But the defense secretary also gave a nod to the difficulty of rapidly detaching military systems from the AI tool, given how widely used they have become. He said that Anthropic would continue to provide services “for a period of no more than six months to allow for a seamless transition to a better and more patriotic service”.

Since the break with Anthropic, the rival company OpenAI has stepped into the breach. Sam Altman, OpenAI’s CEO, said he had reached agreement with the Pentagon for use in its classified network of the company’s tools, which include ChatGPT.