Seventy-six cybersecurity professionals have signed an open letter urging the U.S. government to lift its export control order on Anthropic’s Fable and Mythos models, warning that removing advanced AI capabilities from network defenders while adversaries continue to develop their own tools represents a serious national security risk.
Prominent signatories include former Facebook chief of security Alex Stamos, Bugcrowd founder Casey Ellis, cryptographer Jon Callas, and Luta Security founder Katie Moussouris, who separately published a detailed critique of the underlying technical evidence. Moussouris reviewed a private copy of the Amazon security research paper reportedly used to justify the order and concluded that the behaviour it described was not a meaningful guardrail bypass but rather a standard defensive security workflow of finding, fixing, and testing vulnerable code. The same capabilities, she argued, are replicable using OpenAI’s GPT-5.5, Anthropic’s own Opus 4.8, and publicly available Chinese models.
The U.S. Commerce Department invoked an obscure export control directive without providing Anthropic specific details of its concern, forcing the company to suspend access to both models globally. Analysts and policy observers described the action as unprecedented in its unilateral reach, with Tech Policy Press editor Justin Hendrix warning the move would raise concerns among foreign governments about the reliability of American AI for critical applications. Reports over the weekend suggested the directive may have stemmed from political tensions between Anthropic and the Trump administration rather than a clear technical finding.
