Trump Orders Anthropic to Block Fable 5, Mythos 5 Access Abroad

Anthropic disabled its two most advanced AI models, Fable 5 and Mythos 5, after the Trump administration ordered the company to block foreign access. One startup CEO said the move and Anthropic's response "will send shockwaves across AI labs."

Anthropic disclosed the order Tuesday evening, citing an export directive under the International Emergency Economic Powers Act. Users outside the United States lost access to both models within hours. The company said it cut off cloud API keys and download options for overseas customers.

Fable 5 and Mythos 5 are safety-focused large language models used by universities and private research groups in Europe, Japan, and Singapore for adversarial testing. Their removal from international use halts ongoing red-teaming projects that depended on those specific architectures.

The White House did not comment on the directive. Two people familiar with the process said the administration flagged the models as dual-use because their code could be adapted for disinformation campaigns or automated cyberattacks.

For publicly traded tech companies, the immediate impact is small. Amazon and Google host Anthropic's models on their cloud platforms. The loss of foreign usage fees from those two models will barely move revenue. The larger read-through is regulatory.

This marks the first time a U.S. president has used executive power to bar a single private AI model from export. Until now, controls targeted chips and training hardware, not the models themselves. The precedent opens the door for similar orders against Meta's Llama family or OpenAI's next release.

The order lands ahead of a House committee markup of the AI Export Competitiveness Act, scheduled for March 28. The bill would codify model-specific threshold rules and exempt open-weight models below a certain parameter count. Supporters say the Anthropic action shows why legislation is needed; critics call it an overreach that will fragment global research.

Anthropic separately confirmed that Fable 5 and Mythos 5 will remain accessible inside the U.S. The company said it will use its remaining safety research capacity on domestic projects. No timeline was given for restoring international access.

One venture investor described the situation as "a switch turning off a key piece of global safety infrastructure." The same investor said the long-term effect depends on whether other labs voluntarily restrict models to avoid similar government orders.