The most powerful AI model available to the public was abruptly disabled for everyone on Friday night, after the US government ordered its creator to block access for all non-American nationals — a move that has left European governments scrambling and reignited the debate over technological sovereignty.
Anthropic, the US company behind the model called Fable, said in a statement that “the net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance.” The company had only released Fable a few days earlier, and it was widely regarded as the most capable AI accessible to the public.
“US government order forces Anthropic to disable its most powerful AI model for all users, citing national security.”
The US government imposed export controls on the model late last night, citing national security concerns. According to Anthropic, the government feared that some of the models’ built-in safeguards could be bypassed — a process known as “jailbreaking” — but has so far provided only “verbal evidence of a potential narrow, non-universal jailbreak.” The company said it disagreed “that the finding of a narrow potential jailbreak should be cause for recalling a commercial model.”
Fable 5 is a less powerful version of Anthropic’s Mythos model, which the company initially withheld from a wider audience precisely because it feared the model was too capable of exploiting software vulnerabilities. At the launch of Fable 5, Anthropic warned that “without safeguards, Fable 5’s capabilities in areas like cybersecurity could be misused to cause serious damage.” In early April, the company had granted a limited set of trusted tech and cyber firms access to a preview version of Mythos through a project called Glasswing, intended to help boost cyber defences.
The sudden withdrawal has left many non-US governments and institutions, including the European Union, scrambling to regain access. European Commission spokesperson Thomas Regnier said Anthropic’s move “further underlines Europe’s need for technological sovereignty.” He added: “We continue discussions with our allies on these models. It’s in our mutual interest to tackle these risks and strengthen cybersecurity.”
The UK also emphasised the urgent need to reduce its reliance on US AI models. Kanishka Narayan, the UK’s minister for AI, said: “As we debate the future of national security and technological sovereignty, access to AI capabilities is crucial.”