In mid-June, the U.S. government ordered Anthropic to restrict two of its most capable models, Fable 5 and Mythos 5, to U.S. citizens only. Because Anthropic cannot easily verify the citizenship of everyone using a model, Anthropic pulled access for everyone, including close allies. The trigger, we now know, was a red-team exercise in which Mythos broke into almost all of the NSA's classified systems in hours — a result that turned a safety story into a capability story and retroactively explained the severity of the June 12 restriction order. We covered the order itself when it landed — see the government pulled a frontier model.
Key facts
What: New testimony reframes the Mythos export ban: a top general reportedly told a senator the model breached almost all classified systems in a red-team test, not in weeks but in hours.
When: 2026-06-24
Primary source: read the source
