Artificial intelligence company Anthropic has suspended access to its newly released Claude Fable 5 model after US authorities raised national security concerns just days after its public debut.
The company announced that it had been ordered to block foreign nationals from using Claude Fable 5 and Mythos 5, describing the move as necessary to comply with government directives.
“The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance,” Anthropic said in a statement posted on its website.
Claude Fable 5 is the latest version of Anthropic’s AI platform, competing directly with products such as ChatGPT and Gemini. The company had previously described the model as exceptionally powerful and warned that its advanced capabilities could potentially be misused to exploit computer systems.
According to Anthropic, US national security officials did not identify any specific threat but expressed concerns about a possible method for bypassing, or “jailbreaking,” the model’s safeguards.
The company said it reviewed demonstrations of the technique and found that it only exposed a small number of previously known vulnerabilities. It also argued that similar weaknesses could be identified using other publicly available AI systems without bypassing restrictions.
Before launching Fable 5, Anthropic highlighted a range of security measures designed to prevent cyber abuse. The model underwent limited testing with selected organisations following a private preview in April due to concerns about its ability to assist with sophisticated cyber operations.
The suspension comes amid growing scrutiny of Anthropic’s relationship with the US government. The company is already engaged in a legal battle with the Trump administration over efforts to restrict the use of its AI tools by government agencies.
The latest development has also drawn international attention. The European Union said the incident underscored the importance of reducing dependence on foreign technologies, as it continues to pursue greater technological sovereignty.
AI experts warn that restricting access to advanced models could slow independent testing and global collaboration on AI safety. Gina Neff, Professor of Responsible AI at Queen Mary University London, said the industry is entering “uncharted territory” as AI systems rapidly gain new capabilities.
Anthropic has recently faced criticism from senior US officials, including President Donald Trump and Defence Secretary Pete Hegseth, who reportedly designated the company a “supply chain risk” for government use.
Anthropic is challenging that designation in court, and a judge has temporarily blocked its enforcement while the case proceeds.
The US Department of Commerce has not yet commented on the latest restrictions.
