Anthropic has announced it will “abruptly disable” its most advanced AI models for all users after the US government ordered the company to block access for foreign nationals, citing national security concerns.
The company received an export control directive to suspend access to Fable 5 and Mythos 5 for all foreign nationals, but was not given specific details about the national security issue, Anthropic said in a statement.
According to the company, it understands that the government believes there is a way to bypass, or “jailbreak,” a safeguard designed to prevent Fable 5 from being used to identify software vulnerabilities.
This order comes just as a previous dispute between Trump administration officials and Anthropic—which is preparing for an IPO—appeared to be easing in parts of the US government.
Anthropic’s relationship with the government broke down 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, which is set to take effect later this year.
The action also marks a major escalation in US efforts to limit foreign adversaries’ AI capabilities. For years, US export controls have focused on the chips and tools that power AI, rather than restricting foreign access to AI itself.
Anthropic said the government has only provided “verbal evidence of a potential narrow, non-universal jailbreak.”
“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.
The government 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.
As recently as Wednesday, Anthropic had called for greater US oversight of AI, including the ability to block models with unacceptable risks. However, it said the government’s action on Friday 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 said.
Anthropic confidentially filed for a US IPO last month, moving ahead of rival OpenAI in the race to reach public markets.
Earlier this week, Anthropic launched an AI model called Claude Fable 5, representing a new level of capability it calls “Mythos-class.” The model includes guardrails that prevent its use in risky areas like cybersecurity, which some users have criticized as “overly broad,” Anthropic said.
Experts have warned that Mythos models, if misused, could dramatically accelerate sophisticated cyber-attacks, especially in sectors like banking that rely on complex, interconnected, and often outdated technology systems.
Anthropic said it had worked with the US government and others on safety before the Fable launch, and that models from rival AI providers showed a similar ability to uncover minor bugs in code.
“The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance. Access to all other Anthropic models will not be affected,” Anthropic said.
Anthropic added that it believes there has been a “misunderstanding” and is working to restore access to the models as soon as possible.
A US official confirmed that the commerce department had issued an export control directive to suspend all access to Fable 5 and Mythos 5 by foreign nationals.
Frequently Asked Questions
Here is a list of FAQs regarding the hypothetical scenario where Anthropic disables its most advanced AI models following a US government order restricting foreign access
General Questions
Q Why is Anthropic disabling its most advanced AI models
A Because a new US government order restricts foreign entities from accessing the most powerful AI systems Anthropic is complying with this order to follow the law
Q Does this mean I cant use Claude at all anymore
A No This likely only affects the most advanced models You will probably still be able to use standard or less powerful versions of Claude
Q Is this permanent
A It depends on the order It could be a temporary pause while the government reviews security risks or it could be a permanent restriction until the laws change
Q Who is affected by this restriction
A Primarily users companies or developers who are located outside of the United States or who are owned by foreign entities USbased users are likely unaffected
Impact on Users Developers
Q I live in CanadaEuropeAsia Will my Claude subscription stop working
A You will likely lose access to the most advanced model tier Your account may be downgraded to a less powerful model or you may only be able to use the API with oldersmaller models
Q Im a developer using the API Do I need to change my code
A Yes probably You will need to update your API calls to use a different model name Check Anthropics documentation for the specific allowed models
Q What if I use a VPN to pretend Im in the US
A That would violate the terms of service and the new law Anthropic will likely block accounts detected using VPNs to bypass the restriction You risk losing your entire account
Q Will my existing conversations or data be deleted
A Unlikely Your account history and data should remain intact but you wont be able to generate new responses using the restricted model
Technical Security Questions
