What happened
Anthropic said it has taken its latest artificial intelligence models, Fable 5 and Mythos 5, offline to comply with a Trump administration directive intended to prevent their use by foreign nationals.
The export controls are described as the U.S. government’s most significant step so far to restrict access to the most advanced AI models. Anthropic had released Fable 5 widely this week. Fable 5 is a limited version of the more advanced Mythos 5 model, which Anthropic had already restricted because of cybersecurity concerns.
Anthropic said it disagrees with the government’s handling of the matter. The company said it received the directive from the U.S. government on Friday afternoon and that the directive did not specify the national security concerns behind the action.
Anthropic said the government should have the ability to block unsafe deployments through a statutory process that is transparent, fair, clear, and grounded in technical facts. The company said the action did not follow those principles.
Anthropic called the situation a misunderstanding and said it hopes to restore access to the models as soon as possible.
The Commerce Department did not immediately respond to a request for comment.
The action came 10 days after President Donald Trump signed an executive order establishing a framework for the federal government to vet the national security risks of the most advanced AI systems for up to one month before their public release. Participation by AI developers would be voluntary under the order.
Who is affected
Anthropic users who had access to Fable 5 and Mythos 5 are directly affected because the models were taken offline.
Foreign nationals are also central to the directive because the action was intended to prevent their use of the models. The article does not specify which foreign nationals, countries, customer groups, or access channels are covered by the directive.
AI developers and organizations building with advanced AI models may also be affected by the broader policy direction. The move signals that access to frontier AI systems may face government restrictions when national security concerns are raised.
Why CISOs should care
This development shows how advanced AI access is becoming a cybersecurity and national security governance issue. Anthropic had already limited access to Mythos 5 because of cybersecurity concerns, and the government directive pushed the company to take both Fable 5 and Mythos 5 offline.
For CISOs, this matters because AI adoption planning cannot focus only on model capability, cost, or productivity. Access controls, export restrictions, national security reviews, and vendor availability can directly affect whether teams can use a model in production.
The incident also highlights the need to track vendor policy and regulatory risk. Anthropic said it disagreed with the government’s handling of the directive and hopes to restore access, but customers still faced a model availability change. Organizations using advanced AI systems should plan for the possibility that access to specific models may be restricted, paused, or changed with little notice.
3 practical actions
- Assess dependency on specific frontier AI models: Anthropic took Fable 5 and Mythos 5 offline after receiving a government directive. CISOs should identify which business, security, development, and automation workflows depend on specific AI models and define fallback options if access changes.
- Review AI access policies for cross-border and foreign national use: The directive was intended to prevent use by foreign nationals. Security and legal teams should review who can access advanced AI tools, where access occurs, and whether internal policies account for export controls or national security restrictions.
- Build vendor availability risk into AI governance: Anthropic said it hopes to restore access, but the models were still taken offline. CISOs should ensure AI governance programs include contingency planning for vendor-imposed pauses, regulatory restrictions, and sudden changes to model availability.
John Kevin Hao is a news and feature writer covering cybersecurity, technology, and business targeted for professional audiences.