On the same day it made its Fable 5 and Mythos models available to customers again, Anthropic released Claude Sonnet 5 as the most agentic Sonnet model yet.
The U.S. government lifted restrictions on the two models after it shut them down on June 12 due to national security concerns, following a report by Amazon researchers who found a method to bypass Fable 5’s safeguards.
Anthropic said to get Fable 5 restored as quickly as possible, it trained an improved safety classifier that targets and blocks the jailbreaking behavior that led the government to apply export control to the models. While Mythos 5 has been restored as of June 30, it is still only available to a limited number of users.
In the case of Sonnet 5, however, Anthropic said the new model can use tools such as browsers and terminals while running autonomously at a level that would otherwise require more expensive models. The model’s performance is close to that of the Opus 4.8 model, but at a lower price, Anthropic said.
The model is available at $2 per million input tokens and $10 per million output tokens from now till August 31. After that, pricing moves to $3 per million input tokens and $15 per million output tokens.
The Key Lessons for Enterprises
While it appears that Anthropic has cleared this hurdle with the U.S. government, enterprises should still use this episode to evaluate the models they currently use.
“For enterprises, this drives home that they should architect for model optimality,” said Kashyap Kompella, CEO and founder of RPA2AI Research.
He added that enterprises should not lock critical workflows into a single vendor or model family.
“Companies will need to match use cases to different grades of machine intelligence,” Kompella said. “Some tasks need the very best model available. Many others can run on a less capable, cheaper, more stable or more globally available model.”
The situation with Anthropic should also signal to enterprises that model governance is more than just looking out for hallucinations, data leakage, employee usage and AI bias. It has expanded to include model licensing and geopolitical and regulatory availability risk.
“For enterprises, this changes how AI strategy should be designed,” Kompella said. “Companies will need to ask: Who in the organization can access which models? Are there country-specific limitations? Are some models available only to vetted customers or only for certain use cases? Can offshore teams use the same tools as U.S. teams? What happens if a government directive interrupts access?”
He added that the delay in the full release of OpenAI’s GPT-5.6, while the government reviews it, also shows that the Anthropic incident is not isolated.
The U.S. and Anthropic
Nevertheless, the U.S. government also must balance its views on models. With the government aiming to top China, Europe and other open source and sovereign AI programs, “the U.S. wants to manage risk, but it does not want to push the world away from American AI infrastructure,” Kompella said.
So, a conundrum arises: the government needs to manage national security concerns about cyber misuse and advanced model capabilities while remaining competitive and safeguarding the commercial interests of American AI model providers.
The Fable 5 and Mythos 5 situation will likely lead Anthropic to be careful about how it markets its models. With the recent release of Mythos and Project Glasswing, Anthropic has called its models the most powerful and even made it appear as if providing public access would be dangerous.
“But there is a point at which safety rhetoric becomes a regulatory invitation,” Kompella said. “If a company repeatedly tells governments that its systems are exceptionally capable, difficult to contain and potentially dangerous, governments may eventually take that claim seriously.”
