The US security community has jointly urged the revocation of the Anthropic ban, warning that restricting defensive tools would lead to losing the AI race with China.

According to Beating, a cybersecurity expert group of over 40 people, led by former Facebook Chief Security Officer Alex Stamos, signed an open letter protesting the Trump administration's export ban on Anthropic's most powerful AI model. The letter argues that forcibly shutting down large models like Mythos and Fable 5 not only fails to fundamentally eliminate security vulnerabilities but also deprives defenders fighting against AI-automated hacking attacks of a crucial weapon. The White House's export restriction decision stemmed from a vulnerability report submitted by Amazon security researchers. The White House was concerned that Fable 5 could automatically generate proof-of-concept code for vulnerabilities and, under certain conditions, evolve into a fully autonomous attack chain. However, Stamos points out that the White House's concerns are misguided; the regular version of Fable 5 cannot scan the entire Linux kernel and locate all security vulnerabilities. The version accused of having autonomous attack transformation capabilities is actually limited to the unreleased Mythos 5 and Mythos Preview, which are only tested internally by designated organizations. The open letter emphasizes that automatically generating vulnerability proof code is not a technology exclusive to Fable 5. Equivalent levels of vulnerability analysis and code generation can be achieved through OpenAI's GPT-5.5, Anthropic's Opus and Sonnet, and even China's Kimi 2.7. Stamos warns that Chinese open-source models are catching up to Fable 5 in their ability to analyze system defects. At a time when adversaries are stockpiling and exploiting vulnerabilities, the US's decision to discontinue its most advanced defense tools is undoubtedly a foolish act of self-destruction.