US artificial intelligence company Anthropic has disabled access to two of its flagship AI models, Fable 5 and Mythos 5, after receiving a government directive prohibiting foreign nationals from accessing them on national security grounds. The order, reportedly issued by Commerce Secretary Howard Lutnick, came just three days after Fable 5's public launch; Anthropic says it believes the government is concerned about a potential "jailbreaking" method that could allow the model to assist hacking, though the company disputes that this poses a meaningful threat beyond what existing public models already enable. The move marks a further deterioration in relations between Anthropic and the Trump administration, which previously cut Pentagon contracts with the firm after it refused to allow its technology to be used for mass surveillance or autonomous weapons.