The US government’s latest U-turn on Anthropic’s Mythos sends mixed signals on AI governance

(Isabella Wilkinson – Chatham House) On Tuesday, the United States Department of Commerce removed restrictions on two of Anthropic’s new advanced AI models that have prompted security concerns: Mythos 5 and Fable 5. This is a major change in the way the US controls frontier AI and comes after recurring flip-flopping on the issue. The move, described in a letter by Commerce Secretary Howard Lutnik to Anthropic, lifts the export control directive issued by the Trump administration less than three weeks ago. That 12 June directive banned non-US nationals from accessing the two models. This ban included foreign employees at US companies and cyber defenders from international partners. In response, Anthropic suspended access to Mythos and Fable for all users a day later. The administration then partially changed its approach. On 26 June, Anthropic said the US government had allowed it to release Mythos 5 but had reserved access to the model to only a select group of ‘trusted’ big companies and agencies: all of them, unsurprisingly, from the US. Now, Anthropic says it is coordinating with the government to expand Mythos access to a broader group including international partners. As of 1 July, Fable 5 – which Anthropic says has stronger safeguards than Mythos 5 – is available to public users globally. – The US government’s latest U-turn on Anthropic’s Mythos sends mixed signals on AI governance | Chatham House – International Affairs Think Tank