The U.S. Commerce Department ordered on June 12, 2026, that Anthropic must obtain a license before providing its Fable 5 and Mythos 5 models to any foreign person. This directive led the company to temporarily shut down public access to the systems. Commerce Secretary Howard Lutnick sent a letter to Anthropic CEO Dario Amodei on June 12, 2026, stating that a license was required to provide Fable 5 and Mythos 5 to any foreign person worldwide.

Anthropic concluded that compliance with the June 12, 2026 license requirement meant shutting the Fable 5 and Mythos 5 models down for all users. The restriction applied to Anthropic's own employees.

Prior to the order, Amazon security researchers reportedly found a way to bypass the guardrails of Anthropic's Fable 5 and Mythos 5 models. Amazon CEO Andy Jassy relayed findings regarding Anthropic's model guardrails to Treasury Secretary Scott Bessent. Anthropic stated that the letter from Commerce Secretary Lutnick did not provide specific details of the national security concern. The U.S. government cited the Export Control Reform Act of 2018 and its deemed-export rules as the basis for the June 12, 2026 order against Anthropic.

Public access to Anthropic's Fable 5 model was restored on June 30, 2026. The Commerce Department agreed to lift its restrictions after Anthropic strengthened the models’ safety guardrails. These changes resulted in a collapse of the models’ benchmark scores. According to one experiment, the new Fable 5 completed only 3 of 12 tasks that would have been routine before the new controls.

A July 1, 2026, update from Anthropic revealed that its updated safety classifier blocklisted the specific jailbreaking technique in 99% of cases. The company acknowledged that a very small fraction of cases might still allow insufficiently detailed cyberattack information.

In March 2026, the Pentagon labeled Anthropic a supply chain risk after the company sought limits on how its models would be used. This designation preceded the June export control order.

On June 23, 2026, Legion LegalTech filed a lawsuit arguing that the directive against Anthropic exceeds every source of statutory authority on which it could conceivably rest. The lawsuit invokes the major questions doctrine, referencing the Supreme Court’s February 2026 decision striking down the administration’s emergency-powers tariffs. Legion LegalTech's lawsuit argues that the International Emergency Economic Powers Act does not apply because its Berman Amendment excludes informational materials.