Anthropic Suspends, Then Restores Claude Fable 5 and Mythos 5 After Export Controls Lift
Anthropic suspended Claude Fable 5 and Mythos 5 for nearly three weeks in June 2026 to comply with U.S. export controls, then restored them on July 1, 2026, the day after the controls were lifted. To prevent misinformation, the company embedded a notice in Claude Opus 5's system prompt, directing the model to an official statement. The episode highlights how AI companies handle events occurring after a model's training cutoff.
