When the U.S. Commerce Department ordered Anthropic on June 12, 2026, to immediately prevent all foreign nationals from using the artificial intelligence company’s two most advanced large language models, it disabled its Claude Fable 5 and Mythos 5 models within hours, making them inaccessible to everyone.
Anthropic had little choice. The letter, citing national security concerns, barred access by all foreign nationals, including Anthropic’s own noncitizen employees. With no way to immediately collect and validate each and every user’s nationality, including those who were outside the country, the company shut the models off for everyone.
The Commerce Department agreed to lift its restrictions on June 30 after Anthropic significantly strengthened the models’ safety guardrails. While this may sound like a good thing, these guardrails resulted in a “collapse” of the models’ benchmark scores, demonstrating lower overall intelligence and capacity.
In other words, the department rescinded its directive only after Anthropic’s models were hobbled to the point that many benign queries now trigger the guardrails. According to one experiment, the new Fable 5 completed only 3 of 12 tasks that would have been routine before the new controls.
