Anthropic seeks rehearing on Pentagon blacklisting appeal in D.C. federal court

Anthropic Seeks Rehearing

Anthropic has petitioned a federal court in Washington, D.C. for a rehearing on its appeal concerning the Pentagon's decision to blacklist the company's AI models. This move follows a September ruling by the D.C. Circuit that upheld the Pentagon's designation.

Pentagon's Blacklisting and Anthropic's Stance

The Defense Department, under Pete Hegseth, labeled Anthropic a national-security "supply chain risk" in March. This action prevented defense contractors from using Anthropic's technology in their work with the agency. Anthropic's attorneys argue this designation was retaliation because the company declined to permit its models for mass surveillance of Americans or lethal autonomous warfare, and publicly stated these AI-safety commitments.

Legal Background

Anthropic sued the Trump administration to reverse the blacklisting. The D.C. Circuit's 2-1 decision in September rejected Anthropic's argument that the ban on its Claude models was arbitrary, unauthorized, and unconstitutional. In a separate case, a San Francisco federal judge ruled in August that the DOD had violated Anthropic's First Amendment rights, deeming the supply chain risk designation illegal retaliation.

Breakdown in Negotiations

Before the public dispute, Anthropic had been a partner with various U.S. agencies, including the DOD. A $200 million contract was signed with the Pentagon in July 2025. However, negotiations for deploying Claude on the DOD's GenAI.mil AI platform collapsed in September of that year, leading to the current conflict.