“While this action concerned a single AI model, it appears to represent a significant new application of export control authorities to advanced AI systems and therefore raises important questions for the broader U.S. AI ecosystem, American competitiveness, and the future development and deployment of frontier AI technologies,” they wrote in the letter sent Thursday.
The Commerce Department placed export controls on Anthropic’s newest AI models, named Mythos and Fable, last week, essentially forcing them offline. But the government has provided no official explanation for a move that has shaken trust around the world that topflight American AI systems can be depended upon.
The Commerce Department did not immediately respond to a request for comment. It told Anthropic it was imposing the restrictions under powers allowing it to control the export of technology that officials believe could fall into the hands of a foreign military or spying agency, according to a copy of the letter published by Bloomberg.
Anthropic’s AI models targeted by the administration are closely related. Mythos has been shown to be adept at finding security holes in computer code and Anthropic announced in April that it would provide access to only a small group of partners to avoid harmful use of its technology.
Fable is a version of Mythos with additional safeguards designed to tame its hacking powers that was made publicly available last week. Amazon alerted the government that its researchers found there might be a way to bypass those measures, which Anthropic said appeared to have triggered the government ban.
The company has disputed the seriousness of Amazon’s findings and its technical experts met with government officials this week.
The letter from House lawmakers was signed by California Reps. Sam Liccardo (D), Ted Lieu (D) and Jay Obernolte (R), as well as Rep. Scott Franklin (R-Florida). They asked Commerce Secretary Howard Lutnick for information on what risk his department saw in allowing Anthropic’s models to remain online and raised concerns about the implications of the sweeping restrictions for the development of AI.
Liccardo represents a district that includes much of Silicon Valley. Obernolte, a video game developer, has become a leading Republican voice on AI issues, releasing a proposed package of regulations for the technology this month. Lieu leads a Democratic commission on AI; Franklin was appointed to a bipartisan House task force on AI in 2024.
The lawmakers want answers by the end of next week about what analysis officials conducted before imposing the export controls and whether the capabilities of Anthropic’s system are different from other AI tools. OpenAI, the maker of the GPT chatbots, has also developed an AI model with powerful cybersecurity abilities. (The Washington Post has a content partnership with OpenAI.)
“It is important for Congress, industry participants, and the public to understand what principled distinctions, if any, the Department is drawing among advanced AI models, how those distinctions are evaluated, and what guidance developers can rely upon to assess whether their own systems may become subject to similar restrictions in the future,” the lawmakers wrote.
Anthropic had clashed with the Trump administration before last week. In the winter, it was involved in a stand off with the Pentagon about rules for the use of its systems by the military. Dario Amodei, Anthropic’s chief executive, sought guardrails for mass domestic surveillance and fully autonomous weapons, prompting officials to brand it a national security risk.
In recent weeks, the Trump administration also grew concerned about a South Korean telecommunications company that Anthropic granted access to Mythos. Officials considered imposing export controls at that time but Anthropic revoked the company’s access and the administration held off on the restrictions, The Washington Post previously reported.
