Microsoft and a coalition of the world’s most powerful technology companies have backed Anthropic in a legal battle against the Pentagon that threatens to set a damaging precedent for how the government can treat AI companies that prioritize ethics. Microsoft filed an amicus brief in a San Francisco federal court calling for a temporary restraining order against the supply-chain risk designation, while Amazon, Google, Apple, and OpenAI filed a separate supporting brief. The coordinated response reflects the industry’s shared alarm about the implications of the Pentagon’s action.
The designation that sparked this legal battle was applied to Anthropic after the company refused to allow its Claude AI to be used for mass surveillance of US citizens or to power autonomous lethal weapons during a $200 million contract negotiation. Defense Secretary Pete Hegseth formalized the designation following the breakdown of talks, triggering the cancellation of Anthropic’s government contracts. Anthropic filed two simultaneous lawsuits in California and Washington DC.
Microsoft’s participation in the coalition is grounded in its direct integration of Anthropic’s technology into military systems and its participation in the Pentagon’s $9 billion cloud computing contract. Additional federal agreements spanning defense, intelligence, and civilian agencies further deepen the company’s stake in this dispute. Microsoft publicly argued that the government and technology sector needed to cooperate to ensure advanced AI served national security without crossing ethical lines.
Anthropic’s court filings argued that the supply-chain risk designation was an unconstitutional act of retaliation for the company’s publicly stated AI safety positions. The company disclosed that it does not currently believe Claude is safe or reliable enough for lethal autonomous operations, which it said was the genuine basis for its contract demands. The Pentagon’s technology chief publicly ruled out any possibility of renegotiation.
Congressional Democrats have separately pressed the Pentagon for answers about whether AI was involved in a strike in Iran that reportedly killed over 175 civilians at a school. Their formal inquiries are adding legislative urgency to a battle that could set a damaging precedent for the entire AI industry. Together, the Microsoft-led coalition and congressional scrutiny are creating an extraordinary level of pressure on the Pentagon to reconsider its approach to AI governance.