Claude Fable 5 was made available to global users on June 9, but just three days later, the US Department of Commerce issued an export control directive on national security grounds, requiring Anthropic to suspend access. The controversy stemmed from Amazon researchers using the model to obtain network attack methods. Anthropic argued that other models, including its own Claude Opus 4.8, could achieve similar results.
After negotiations from June 12 to 30, Anthropic agreed to add extra guardrails: some cybersecurity queries would be intercepted and routed to the less capable Opus 4.8. On July 1, Claude Fable 5 access was restored, but only on Anthropic-controlled platforms; third parties like AWS resumed later. Previously, the more advanced Claude Mythos 5 had been made available to government and critical infrastructure partners in April and was restored earlier on June 26.
This incident is one of the most notable conflicts between US AI companies and the government this year, involving Anthropic, Amazon, Google, Microsoft, and OpenAI. Commerce Secretary Howard Lutnick described the negotiations as making 'significant progress,' but after restoration, some users reported performance degradation, especially in biology, which Anthropic has not officially addressed.