Anthropic has disabled access to its Fable 5 and Mythos 5 artificial intelligence models following an export control directive from the U.S. government that cited national security concerns, according to a company announcement on Friday.
The company said it received an order at 5:21 p.m. ET instructing it to suspend access to the models “by any foreign national,” whether located inside or outside the United States, including foreign national employees of Anthropic. To comply with the directive, Anthropic immediately disabled the models for all customers. The company said its other AI models would remain unaffected.
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Models Suspended Days After Launch
The move came only days after Anthropic announced Fable 5 and Mythos 5, which it described as state-of-the-art models that performed strongly across a range of industry benchmarks.
Anthropic said Fable 5 represented the first time it had released such an advanced model to the public. The company attributed the broader release to safeguards designed to block responses in specific high-risk areas.
The models were built on the earlier Claude Mythos Preview release. According to the company, that version attracted significant interest from Wall Street and government officials because of its advanced cybersecurity capabilities. Anthropic said it had never intended to make the model generally available and instead limited access to a select group of companies through a cybersecurity initiative known as Project Glasswing.
Company Questions Government Process
In a statement issued Friday, Anthropic said the government did not provide specific details regarding the national security concern behind the order. The company also apologised to customers affected by the disruption.
“As we have stated publicly, we believe the government should have the ability to block unsafe deployments, as part of a statutory process that is transparent, fair, clear, and grounded in technical facts,” the company said. “This action does not adhere to those principles.”
The company’s comments indicate disagreement with the manner in which the restriction was implemented, while confirming that it had complied with the directive.
Dispute With U.S. Defence Authorities Continues
The latest development follows an earlier public dispute between Anthropic and the U.S. Department of Defense.
According to the report, negotiations between the two sides broke down, after which the Department of Defense designated Anthropic as a supply chain risk. The designation means defence contractors must certify that they will not use Anthropic’s Claude models in military-related work. The report noted that such a label has historically been reserved for foreign adversaries.
Anthropic has challenged the decision in court, filing a lawsuit against the Trump administration in an effort to reverse the blacklisting. The litigation remains ongoing.
