Shortly after Jassy shared the company’s findings with the government, it made the call to block its use by foreign nationals. Complicating this issue is that many of Anthropic’s researchers are foreign-born, meaning they were barred from accessing their own product.

In a statement, Anthropic disputed the government’s characterization of the issue as a “jailbreak.” It argued that many of the same vulnerabilities could be discovered using other publicly available models, including GPT 5.5. Some security researchers appear to back the company’s interpretation. Katie Moussouris, the founder and CEO of LutaSecurity posted on BlueSky that “I’ve seen the paper. It’s not a jailbreak.” Former Commerce Department official Kate Koren speculated to the WSJ that the White House’s dislike of Anthropic may have influenced the decision.

Anthropic and the Trump administration have been at odds for some time over the company’s refusal to allow its AI to be used for mass surveillance of Americans or to power lethal autonomous weapons. In February, Trump instructed federal agencies to stop using Anthropic’s AI. And just hours later, Secretary of Defense Pete Hegseth designated the company a supply chain risk.

The government and the company seemed to have made amends, and the two had worked together to expand access to Mythos. However, now the two seem destined to clash again.