The U.S. Department of Commerce lifted export controls on Anthropic’s Claude Fable 5 and Mythos 5 models on Tuesday, ending an 18-day standoff between the AI company and the Trump administration. Fable 5 returns to global access on Wednesday, July 1.
NCT covered the developing export control situation on June 30, when Fable 5 was expected to return to general access. The Commerce Department’s formal confirmation, reported by CNBC, Bloomberg, and Axios, arrived Tuesday evening.
What Triggered the Suspension
The government issued the export control directive on June 12 after Amazon researchers found a method to bypass Fable 5’s safety classifiers. The technique prompted the model to identify software vulnerabilities, and in one case, produce code demonstrating how a vulnerability could be exploited.
Anthropic’s post-incident analysis, published alongside the redeployment announcement, concluded that the behavior was not unique to Fable 5. Testing showed that Claude Opus 4.8, GPT-5.5, Kimi K2.7, and several other models could reproduce the same vulnerability identification and exploitation demonstration.
“The reported technique did not expose any unique Mythos-level cyber capabilities,” Anthropic wrote. “The behavior reflected a borderline case for Fable 5’s safeguards.”
How Anthropic Fixed It
Anthropic trained a new safety classifier that blocks the specific exploit described in the Amazon report in over 99% of cases. Researchers from the Commerce Department’s Center for AI Standards and Innovation (CAISI) tested both the original and updated safeguards and “agree that they are extraordinarily strong,” according to Anthropic.
The fix comes with a tradeoff: the new classifier flags more benign requests during routine coding and debugging tasks. Anthropic said it will continue refining the classifier to reduce false positives.
The Negotiation
Anthropic co-founder Tom Brown led negotiations with the Trump administration after CEO Dario Amodei was effectively sidelined, according to CNBC. Amodei has been a target of the administration for his outspoken views on AI safety and his vocal support of Kamala Harris during the 2024 presidential election. Commerce Secretary Howard Lutnick’s letter granting Mythos 5 access on June 26 was addressed to Brown, not Amodei.
“Over the past two weeks, we have worked closely with Anthropic to analyze and approve Fable 5 to ensure alignment across the US Government and strengthen America’s leadership in AI,” Lutnick wrote on X.
Access Details
Fable 5 will be available on Claude.ai, Claude Code, and Claude Cowork starting July 1. For Pro, Max, Team, and select Enterprise plans, Fable 5 will be included for up to 50% of weekly usage limits through July 7, after which it becomes available via usage credits. Access through AWS, Google Cloud, and Microsoft Foundry will follow.
Mythos 5 access has been restored to a set of U.S. organizations following Lutnick’s June 26 approval. Broader access, including international partners, will expand through Anthropic’s Glasswing cybersecurity program.
Industry Fallout
The 18-day suspension accelerated competitive dynamics. As CNBC reported, Chinese open-source models proved almost as capable and significantly cheaper during the window when Anthropic’s top models were offline. Tech executives and investors raised concern that the restriction gifted Chinese developers valuable time to close the capability gap.
Anthropic also announced a shared industry framework for evaluating jailbreak severity, developed with Amazon, Microsoft, Google, and other Glasswing partners, plus deeper pre-release testing collaboration with the federal government. The incident appears to have produced lasting infrastructure for how AI companies and the government interact on model security, even after the immediate crisis resolved.