It was likely a dealbreaker for Anthropic, since the export control excluded Anthropic’s own foreign employees from being able to access Mythos internally. Naturally, this makes model development hard.

Apparently, you won't be able to use Mythos OR Fable for coding. From their announcement...

> routine tasks like coding and debugging will fall back to Opus 4.8.

Presumably they reached a backdoor agreement.

Presumably there are different levels of safety. I assumed Fable was a nerfed Mythos, and not just via safety harnesses but actual model degredation.