The US government has ordered Anthropic to halt access to its most advanced artificial intelligence models, Fable 5 and Mythos 5, due to national security concerns. The restrictions apply broadly, impacting not only foreign governments and companies but also Anthropic’s own employees. The move effectively suspends access for all clients of the AI developer. Anthropic has described the situation as a “misunderstanding” and has complied with the directive by disabling the models. Details regarding the specific security risks prompting the intervention remain limited. This action highlights increasing US scrutiny of advanced AI technology and its potential implications for national interests. The situation raises questions about the future of international access to cutting-edge AI development.