Anthropic has disabled access to its two newest artificial intelligence models, Fable 5 and Mythos 5, after the US government ordered it to stop providing them to foreign nationals.
The company said an export-control directive from the US Commerce Department, issued on Friday, required it to suspend all access to the models by any foreign national, whether inside or outside the United States, including its own non-citizen employees. According to reports, the directive was sent in a letter from Commerce Secretary Howard Lutnick to Anthropic's chief executive, Dario Amodei.
Rather than block individual users, Anthropic disabled both models for all customers. The company said its other models, including Claude Opus 4.8, were not affected.
In a statement, Anthropic said: "We apologize for this disruption to our customers." It said it believed the order was a misunderstanding and that it was working to restore access.
What the models are
Fable 5 is Anthropic's consumer-facing model. It is built on Mythos, a more powerful underlying system with significant cybersecurity capabilities, and includes safeguards intended to stop users reaching those capabilities. Anthropic said the government had cited a technique that can bypass those safeguards.
The company said the vulnerability was narrow, affected a single case, and reflected a capability already available in other publicly deployed models, including those from OpenAI. It said the letter did not set out the specific national-security concern, and warned that if the same standard were applied across the industry it would "essentially halt all new model deployments." Anthropic said the order affected hundreds of millions of users.
Background
The order is the latest in a series of disputes between Anthropic and the US government. In March, the Pentagon designated the company a "supply chain risk" after it declined contract terms that would have allowed its models to be used for purposes including autonomous weapons and mass surveillance. Anthropic is challenging that designation in federal court. In February, the Trump administration directed federal agencies to stop using the company's models.
Anthropic was valued at about $965bn in a recent funding round and filed confidentially for a stock-market flotation earlier this month.
Reaction
Dean Ball, an AI policy analyst, told Fortune he could not tell whether the order amounted to "lawfare against Anthropic in particular or extreme national-security hawkery."
Peter Girnus, a cybersecurity researcher, told the same publication: "If you describe your product as a munition in every press release, eventually a government takes you at your word."
Anthropic said it was continuing to work with the government to restore access to the two models.
Sources
- Anthropic, Statement on the US government directive to suspend access to Fable 5 and Mythos 5
- Jeremy Kahn, Anthropic disables Fable and Mythos AI models after U.S. government bars it from giving foreigners access, Fortune, 13 June 2026
- Anthropic disables access to Fable 5 and Mythos 5 to comply with government directive, CNBC, 12 June 2026
- Trump admin blocks foreign access to Anthropic's most powerful AI, Axios, 12 June 2026
- Pentagon labels AI company Anthropic a supply chain risk, NPR, 6 March 2026 (background)