Anthropic blocks all public access to Claude Fable 5, Mythos 5 following US government order — what enterprises should do

The US government last night issued an unprecedented export control directive ordering Anthropic to immediately suspend all access to its top-tier Claude Fable 5 and Claude Mythos 5 models for foreign nationals, citing unspecified national security authorities. In response, Anthropic has blocked all public access to both models, globally — meaning no users around the world can access them at this time, even paying enterprise customers and Anthropic employees internally. It's a huge blow and reversal following the public release of Fable/Mythos 5 just three days prior. Current Fable 5/Mythos 5 sessions will end in errors and new queries will be automatically routed to older, less capable models like Opus 4.8. Anthropic says in a blog post that "We believe this is a misunderstand [...]