US appeals court denies Anthropic bid to block Pentagon blacklisting

On April 9, a U.S. appeals court rejected an emergency request by Anthropic to temporarily block its designation as a supply chain risk by the Department of Defence, allowing the Pentagon’s restriction to remain in place while broader litigation proceeds.

The U.S. Court of Appeals for the District of Columbia declined to issue a stay, saying the balance of equities favoured the government, given national security considerations tied to the use of artificial intelligence in military operations, Caliber.Az reports per the American business news channel.

“In our view, the equitable balance here cuts in favour of the government,” the court said, citing the Department’s interest in securing critical AI systems during an active military conflict. The panel acknowledged Anthropic could face financial harm but said it was not sufficient to justify immediate relief.

The ruling means defence contractors are barred from using Anthropic’s Claude AI models in work connected to the Pentagon, though the company may continue to operate with other federal agencies while the case is pending.

The dispute stems from a March decision by the Department of Defence, publicly supported by Defence Secretary Pete Hegseth, which labelled Anthropic a supply chain risk — a designation traditionally reserved for foreign entities. The move requires contractors to certify they are not using the company’s technology in defence-related work.

Anthropic, led by CEO Dario Amodei, has argued the designation is unlawful, arbitrary and retaliatory, and has challenged it in court. The company has also said the restrictions could interfere with its commercial relationships and government partnerships.

A separate federal court in San Francisco previously granted Anthropic a preliminary injunction preventing the administration of Donald Trump from enforcing a broader ban on the use of Claude by federal agencies, creating a split in judicial outcomes across related cases.

Acting U.S. Attorney General Todd Blanche welcomed the appeals court decision, describing it as a “victory for military readiness” and emphasising that operational control over defence technology rests with the government.

The appeals court urged expedited proceedings, signalling that the underlying legal dispute is likely to move quickly through the courts. Anthropic said it remains confident the designation will ultimately be overturned.

By Aghakazim Guliyev