Anthropic, the maker of Claude, has been forced to suspend two of its newest AI models after the US government banned non-American nationals from accessing them.
The US government cited national security concerns as the basis for its order, leading Anthropic to pull both Fable 5 and Mythos 5 from use entirely.
The decision has sparked widespread concern in the UK about the country’s ability to maintain technological sovereignty and keep pace with rapidly advancing AI capabilities.
According to Anthropic, the US raised specific concerns over a “method of bypassing” the AI model, whereby users might be able to trick the bot for more nefarious purposes.
Anthropic acknowledged that Fable had “minor vulnerabilities” but said it had already imposed safeguards following cybersecurity work with both the US government and the UK’s AI Security Institute.
“No testers have yet been able to find a universal jailbreak — a jailbreak method that can very broadly bypass the model’s safeguards, unblocking a wide range of cyber capabilities,” Anthropic said.
The US-based firm said it had no choice but to comply with the legal order, though it made clear it disagreed with the decision and warned that more AI models could face similar bans if the same standards were applied consistently.
Fable had been widely anticipated by users due to its ability to achieve complex tasks such as creating games, coding software, and developing control systems, making the suspension a significant blow to international users.
This is not the first time the Trump administration has clashed with Anthropic, after the AI firm was previously labelled a “supply chain risk” when chief executive Dario Amodei sought to limit the model’s use across defence and military systems over ethical concerns.
UK AI minister Kanishka Narayan responded to the ban with a post on X, writing: “The main lesson: as we debate the future of national security and technological sovereignty, access to AI capabilities is crucial.”
Narayan also defended the government’s decision to fund the UK Sovereign AI unit, an investment fund designed to back homegrown AI founders and reduce dependence on foreign technology.
Former security minister Tom Tugendhat described the ban on foreign nationals as the “inevitable result of technology shaping warfare so that sovereignty is more about code than cannons.”
Tugendhat added: “With high energy costs and the emphasis on safety not opportunity Britain’s response has been to build the brake cutting ourselves off from the future and tied ourselves to the past.”
Former UK government adviser Raoul Ruparel warned the development would serve as a “wake up call” for countries outside the US and China, as potential “security and economic disparities” begin to emerge.
Reform UK’s Zia Yusuf claimed he had warned “for months” about the prospect of an access ban, accusing the government of maintaining “virtually zero sovereign AI capability” in response to the growing crisis.