U.S. Orders Anthropic to Suspend Access to Most Powerful AI Models

The U.S. government has ordered Anthropic to immediately suspend access to its most powerful AI models for all foreign nationals, forcing the company to disable the systems entirely late Friday evening.

The directive, issued by Commerce Secretary Howard Lutnick with assistance from the Commerce Department's Bureau of Industry and Security, targets Anthropic's Fable 5 and Mythos 5 models — both released just days earlier on Tuesday. The order prohibits any foreign national from accessing these systems, whether they are located inside or outside the United States, including Anthropic's own foreign national employees.

"The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national," Anthropic stated in a late Friday announcement.

Because Anthropic could not immediately implement controls to distinguish between foreign nationals and U.S. citizens, the company suspended access for all customers to ensure compliance with the government order.

The models at the center of the directive

Anthropic had positioned Fable 5 and Mythos 5 as its most capable AI systems to date when announcing them earlier in the week. Both models share the same technical foundation but differ significantly in their safety restrictions.

Fable 5, released to the general public, includes robust guardrails that prevent users from asking certain types of questions, particularly those related to cybersecurity and biology. Anthropic acknowledged in its Tuesday release that "without safeguards, Fable 5's capabilities in areas like cybersecurity could be misused to cause serious damage."

Mythos 5, by contrast, was distributed without such restrictions to a limited group of trusted partners, including cybersecurity firms and critical infrastructure companies. This unrestricted version appears to have heightened government concerns about potential misuse if accessed by foreign actors.

Why it matters

This marks an unprecedented direct intervention by the U.S. government into the deployment of a commercial AI system. The move signals that federal authorities view certain advanced AI capabilities — particularly in cybersecurity and biological domains — as strategic national security assets requiring export controls similar to those applied to sensitive military technologies. For AI companies racing to release increasingly powerful models, the directive establishes that the government may impose immediate access restrictions based on capability assessments, potentially disrupting product launches and customer relationships with little warning.

Immediate compliance challenges

The sudden nature of the directive created immediate operational challenges for Anthropic. Rather than risk non-compliance while developing systems to verify user nationality, the company chose the more conservative approach of disabling access entirely for all users.

The incident underscores growing tensions between AI companies' desire to rapidly deploy advanced capabilities and government concerns about national security implications of powerful AI systems.

These details were first reported by NBC News.