The US government has abruptly reversed course, lifting an export ban on Anthropic's most advanced artificial intelligence tools just weeks after ordering the company to restrict access over national security fears.
Anthropic said it will begin restoring access to Claude Fable 5 and Mythos 5 on Wednesday after the US Department of Commerce notified the firm that restrictions had been withdrawn. The two models were abruptly suspended on 12 June over concerns they could be used by hackers to exploit weaknesses in computer systems.
“US lifts export ban on Anthropic's Fable 5 and Mythos 5 AI models weeks after national security suspension.”
The sudden turnaround follows an agreement by Anthropic to address the risks. In a letter seen by the BBC, commerce secretary Howard Lutnick wrote: "Anthropic has agreed to proactively detect and address security risks associated with the models; to work diligently with the US government on protocols and standards and releases for Mythos, Fable, and future models; and to inform the US government of any malicious activity."
Lutnick added that the Commerce Department reserves the right to reconsider lifting export restrictions if necessary.
Fable 5 and Mythos 5 are the company's most sophisticated AI systems, built on its Claude platform – a rival to OpenAI's ChatGPT and Google's Gemini. Fable 5 is designed for the consumer market, capable of deep reasoning and performing complex tasks independently. Mythos 5 is intended for select businesses and cybersecurity experts, and can identify vulnerabilities in computer code and exploit them. Both were released on 9 June.
At the time of the suspension, Anthropic said US authorities had not pinpointed specific concerns. "Our understanding is that the government believes it has become aware of a method of bypassing, or 'jailbreaking' Fable 5," the company said, adding: "However, we disagree that the finding of a narrow potential jailbreak should be cause for recalling a commercial model deployed to hundreds of millions of people."
The US has stepped up oversight of new AI releases amid concerns that advanced models could be misused by military intelligence users in China, Russia or other countries of concern. The government's vetting of which companies can gain access has drawn criticism. OpenAI CEO Sam Altman said last week: "Extensive safety testing is not a bad idea. I just don't like the idea of the government picking the customers."
ChatGPT-maker OpenAI itself delayed a full public launch of GPT-5.6 at the US government's request, limiting access to a small group of vetted partners.
Anthropic announced the lifting of the ban late on Tuesday in a statement on X: "We'll begin restoring access tomorrow."