Not even a week after Anthropic released Fable 5, its most capable model yet for public use, the U.S. government issued an export-control directive ordering Anthropic to block all access to the model, as well as its base model, Mythos 5 — its most capable model, accessible only to a select few cybersecurity defenders and infrastructure providers — for any foreign national. Rather than try to sort access by nationality, Anthropic disabled the two models for all customers worldwide to ensure compliance. The federal government has alleged that Fable 5 and Mythos 5 should not be accessible to foreign nationals for national security reasons and appears to have done so based on jailbreaking concerns, a term referring to prompt-based attacks intended to circumvent the restrictions engineers have put in place.

Full analysis : The net impact of advanced models remains uncertain, but consequential, with advanced AI models lowering barriers for criminals while empowering defenders.