Lutnick’s Letter to Anthropic Warned of Curbs on Top AI Models

The US Commerce Department issued a formal warning to Anthropic PBC last week, demanding the company obtain government permission before allowing foreign nationals to access its top AI models, Fable 5 and Mythos 5. In a letter signed by Secretary Howard Lutnick, the department ordered Anthropic to halt global distribution of these models without prior licensing, citing concerns over potential misuse by adversarial military or intelligence agencies. The letter, dated Friday, invoked US export control laws to justify the restrictions, though no specific rationale was provided. Lutnick’s directive frames the models as civilian technology that could pose national security risks if accessed by foreign entities. Failure to comply with the order could result in civil or criminal penalties, according to the document obtained by Bloomberg News. Anthropic’s Fable 5 and Mythos 5 models are among the company’s most advanced AI systems, designed for high-performance applications. The Commerce Department’s intervention marks a significant escalation in regulatory oversight of AI exports, reflecting broader US efforts to limit the spread of cutting-edge technology to foreign actors. The letter does not specify which countries or entities are targeted but emphasizes that no foreign national—regardless of location—may access the models without explicit approval. This move aligns with growing government scrutiny over AI development, particularly in sectors deemed critical to national defense. While the letter does not outline a timeline for compliance, Anthropic is expected to adjust its access policies to meet the new requirements. The restrictions underscore the tension between innovation and security in the rapidly evolving AI landscape.