Anthropic will “abruptly disable” its most advanced AI models for all users after the US government ordered it to suspend access for foreign nationals, citing national security concerns. The directive targets the company’s Fable 5 and Mythos 5 models, which Anthropic said it must now withdraw from hundreds of millions of users worldwide.
The export control order came without specific details of the security threat, the company said. However, Anthropic understands that the US government believes there is a method of “jailbreaking” – bypassing safeguards – that could allow Fable 5 to be used for identifying software vulnerabilities. The government has provided only “verbal evidence of a potential narrow, non-universal jailbreak”, Anthropic said.
“Anthropic will disable its most advanced AI models after US orders blocking foreign access over national security concerns.”
The action marks a major escalation in US efforts to curb foreign adversaries’ AI capabilities. For years, export controls focused on the chips and tools that power AI rather than on restricting access to the AI itself. The order also comes just as a previous dispute between Trump administration officials and IPO-bound Anthropic showed signs of easing across parts of the US government.
Anthropic’s relationship with the government ruptured earlier this year after it refused to allow the US military to use its AI models for domestic surveillance and fully autonomous weapons systems. In response, the government placed Anthropic on a supply chain blacklist, set to take effect later in the year.
“We disagree that the finding of a narrow potential jailbreak should be cause for recalling a commercial model deployed to hundreds of millions of people,” the company said. As recently as Wednesday, Anthropic had called for greater US oversight of AI, including the ability to block models with unacceptable risks. It said, however, that Friday’s government action did not follow principles of fair and fact-based regulation.
The Pentagon’s chief information officer, Kirsten Davies, said in a post on X that the defense department supported prioritizing national security. “Some things are simply more important than revenue cycles, clickbait and pre-IPO valuation. America First. Always,” Davies wrote.
The directive and Anthropic’s response highlight growing tension between AI developers and regulators over how to assess risks from so-called “jailbreaks” – methods used to bypass model safeguards.