The U.S. government has ordered AI company Anthropic to suspend access to its most powerful models, citing national security concerns. The directive forces the company to completely disable its newly released Fable 5 and Mythos 5 AI systems for all users.
Anthropic, maker of the popular Claude chatbot, announced Friday evening that the Commerce Department instructed it to prevent any foreign national from accessing the models. Since the company cannot distinguish between foreign and domestic users in real-time, it chose to disable the models entirely rather than risk non-compliance.
“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, whether inside or outside the United States, including foreign national Anthropic employees,” the company said in a statement posted online late Friday.
The directive represents an unprecedented government intervention in AI model deployment and signals growing federal concern about advanced AI capabilities falling into foreign hands. Commerce Secretary Howard Lutnick sent the letter with help from the Bureau of Industry and Security, marking the first time the government has forced a complete suspension of cutting-edge AI models after their release.
Anthropic had just released both models on Tuesday, calling them the most powerful AI systems the company had ever created. The timing of the suspension – just three days after launch – suggests the government may have been caught off-guard by the models’ capabilities or received new intelligence about potential risks.
The company itself had warned about the models’ power when releasing them. “Releasing a model this capable comes with risks. Without safeguards, Fable 5’s capabilities in areas like cybersecurity could be misused to cause serious damage,” Anthropic said in its Tuesday announcement.
The two suspended models served different purposes:
- Fable 5 was available to the general public but included strong restrictions on cybersecurity and biology-related questions
- Mythos 5 operated without such safeguards but was limited to select trusted partners, including cybersecurity and infrastructure companies
This government action comes as lawmakers and security officials increasingly worry about AI’s potential for misuse in areas like cyberattacks, biological weapons development, and military applications. The suspension also highlights the challenges companies face when building AI systems powerful enough to trigger national security concerns.
The move could set a precedent for how the government handles future AI releases, potentially creating new compliance burdens for companies developing advanced models. It also raises questions about how the U.S. will balance innovation leadership with security concerns as AI capabilities continue to advance rapidly.
For Anthropic’s customers, the suspension means losing access to what the company described as its most capable AI systems. The company has not indicated when or if the models might return with modified access controls that would satisfy government requirements while allowing domestic use to resume.