Do AI Biorisk Thresholds Need Intermediate Warning Levels? (opens in new tab)

In the Claude Mythos/Fable 5 system card, Anthropic states that the model meets non-novel (CB-1) but falls short of novel (CB-2) biological/chemical weapons development capability thresholds. Despite this difference in conclusions, they introduce protective measures in response to both.This is not the first time there's been a gap between threshold-triggered and actual governance decisions. In 2025, Anthropic activated AI Safety Level 3 (ASL-3) protections with the release of Claude Opus 4 de...