Parsing this evening's events: - The U.S. government approved the release of Fable 5 to the public, clearly under the presumption that the model's cybersecurity capabilities cannot be accessed by hackers, authoritarian regimes, etc. - Recently (today?), "another company" showed the U.S. government that a jailbreak of Fable 5 *is possible*. Yes, a minor jailbreak - but how can a non-technical government official be assured that there aren't also other, more dangerous, jailbreaks in this model that won't be discovered by the CCP? - Anthropic states, completely correctly, that: "We suspect that perfect jailbreak resistance is not currently possible for any model provider. Every safeguard used in the industry is vulnerable to non-universal jailbreaks (which can elicit some cyber information in specific circumstances), and it is likely that universal jailbreaks will eventually be found in the future. We stated this clearly when we released Fable 5." - My best guess is that the U.S. government did not fully realize this at the time when the release of Fable 5 was approved. - Per Axios, the government contacted Anthropic and asked to "pause releasing the... models but was unsuccessful" - i.e., Anthropic told the government to pound sand. - Per Axios, this "prompt[ed] the export control letter". - Per Axios, the U.S. government is *NOT* looking to restrict access to Fable to U.S. nationals forever. "The model needs to remain locked down until the U.S. governent's national security apparatus is hardened", which "could happen in a few weeks". - I interpret Anthropic's reaction as challenging the government: "we believe the government should have the ability to block unsafe deployments, as part of a statutory process that is transparent, fair, clear, and grounded in technical facts. This action does not adhere to those principles." If the Axios article is correct, I do not think any other model providers have anything to fear based solely on this evening's events, because: (1) they would hopefully be smarter than downright rejecting a request by the U.S. government to pause releasing a model, and (2) they will be required anyway under the recent executive order to give the U.S. government at least 30 days to test the model for cybersecurity capabilities - during which time the U.S. government would also be able to shore up its own cybersecurity defenses with the same model. I remain extremely concerned that actions by one particular U.S. lab over the last few months might be moving us closer and closer to the scenario where at least that lab - and potentially all others - will be nationalized.

Breaking: Amazon CEO Andy Jassy was among the tech leaders who raised concerns to senior Trump officials this week re: security risks in Anthropic's newest models. Those convos set in motion the government's new export controls on foreign national access to Mythos and Fable.

The jailbreak that triggered all of this was reported by Amazon.

The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees. The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance. Access to all other Claude models is not affected. We apologize for this disruption to our customers. We believe this is a misunderstanding and are working to restore access as soon as possible. Read our full statement: anthropic.com/news/fable-myt…

This allegedly was triggered by a successful jailbreak of Mythos by an unnamed group who reported it to the government. We will hopefully get details soon.

Claude Fable 5 scores very well on FrontierMath: Tiers 1–4 (v2), reaching 87% on Tiers 1–3 and 88% on Tier 4. This continues a streak of Anthropic models improving rapidly at math.