Anthropic Suspends Claude Fable 5 and Mythos 5 Due to US Export Controls

On June 9, 2026, Anthropic unveiled two AI models, Claude Fable 5 and Claude Mythos 5. However, just three days later, on June 12, 2026, access to both models was halted due to export controls set by the U.S. Department of Commerce. These restrictions were lifted on June 30, 2026, allowing Anthropic to restore access on July 1, 2026. The suspension was acknowledged in the system prompt of Claude Opus 5, which instructs the model to treat the issue as a relevant political matter without offering personal views. It also advises referring to Anthropic’s official statement for more information and to seek updates when available. Simon Willison documented this incident on his blog on August 9, 2026, illustrating the relationship between AI innovation and governmental regulations.