Summary
Anthropic says the U.S. government issued an export control directive ordering the company to suspend access to Fable 5 and Mythos 5 for any foreign national, inside or outside the United States. Anthropic says the operational result is broader: it is disabling both models for all customers while it complies and works to restore service.
According to Anthropic, the directive was tied to a reported jailbreak technique that the company argues only exposed a small number of previously known, minor vulnerabilities and did not demonstrate a broad harmful capability unique to the models. Anthropic says access to its other models is unaffected and publicly disagreed with the standard used to force a recall-style shutdown.
Source
Anthropic statement on Fable 5 and Mythos 5 access
Commentary
This is one of the clearest signs yet that frontier-model access can now be interrupted by national security process, not just technical failure or product choice. Even if the shutdown is temporary, enterprise buyers now have a fresh reason to think about model concentration risk, fallback plans, and how quickly a regulator or government order can change availability.
It also sharpens the fight over how model capability evaluations should be handled. If providers and governments do not align on what counts as a dangerous jailbreak, every major launch will carry more policy risk than the marketing copy admits.