U.S. Government Orders Anthropic to Shut Down Fable 5 and Mythos 5 Models Over National Security Concerns

The U.S. government issued an emergency order Friday requiring Anthropic to immediately block all access to its Fable 5 and Mythos 5 AI models citing unspecified national security concerns, forcing the company to cut off access for all customers including its own employees. Anthropic complied with the directive but noted the government provided no written details about the specific vulnerabilities, only verbal claims of minor jailbreak risks that the company says are available in other models.

Why it matters: This represents a significant precedent for government intervention in AI model deployment and raises questions about transparency, due process, and the criteria for restricting access to advanced AI systems—issues that will shape AI regulation and corporate compliance strategies industry-wide.