On Friday at 5:21 PM, Anthropic received a US export control directive from the Trump administration ordering the company to suspend access to Claude Mythos 5 and Fable 5 to "any foreign national" inside or outside the US, including foreign-national employees.
The directive followed a 90-minute ultimatum delivered to Anthropic around 1 PM ET. A source familiar with negotiations told The Verge that the administration gave the company until the deadline to comply or face export controls imposed by the US Commerce Department.
Anthropicexecutives escalated rapidly. CEO Dario Amodei joined discussions about 1 hour and 15 minutes after the initial call and spoke directly with Treasury Secretary Scott Bessent, Commerce Secretary Howard Lutnick, and National Cyber Director Sean Cairncross—in some cases more than once, according to the source.
The government's action stemmed from awareness of a method to jailbreak Fable 5's safeguards. Anthropic characterized the issue as a "potential narrow, non-universal" jailbreak that had been shared with the government by an unnamed entity. The company declined to identify who reported the vulnerability.
In its statement, Anthropic pushed back on the severity, noting that the capability demonstrated in the jailbreak is "widely available from other models (including OpenAI's GPT-5.5)." The company emphasized that the behavior was not unique to Fable 5.
Mythos 5 and Fable 5 are built on the same foundation as Anthropic's Mythos Preview, which the company had deemed too dangerous to publicly release. Mythos 5 was restricted to a select group of government agencies and companies, while Fable 5, featuring additional safeguards, was positioned as "safe for general use."
Reports point to Amazon CEO Andy Jassy as a potential source of the concern, suggesting researchers at Amazon red-teamed Fable 5 and flagged findings to the US government. Semafor reported, citing one source, that the US government had been concerned a China-linked group accessed the technology, though Anthropic said it immediately revoked access to a telecommunications company when the government raised the issue weeks earlier.
X user David Sacks, the US government's former AI and crypto czar (who stepped down in March), confirmed that a "highly credible trusted partner of both Anthropic and the USG" had tested Fable 5 and "came forward with a jailbreak of those guardrails."
The immediate consequence: Anthropic had to completely disable products it had promoted throughout the prior week and escalate negotiations with the Trump administration in hopes of reversing the directive. The outcome of those talks could reshape export policy across the entire US AI industry.