The U.S. government has ordered Anthropic to suspend access to its most advanced AI models, Claude Fable 5 and Mythos 5, for all foreign nationals, citing national security concerns. Anthropic has indicated it will disable these models broadly rather than attempt to selectively restrict access by nationality. This represents a significant escalation in U.S. government control over frontier AI model access and export.

Security Architect’s Take: Organisations relying on Claude Fable 5 or Mythos 5 within their cloud AI pipelines should immediately audit their dependencies on these models and prepare contingency plans using alternative models or providers to avoid service disruption. Review your AI supply chain risk posture — government-mandated access restrictions can be imposed with little notice.

Original advisory: U.S. Orders Anthropic to Suspend Fable 5 and Mythos 5 Access for Foreign Nationals