Microsoft has filed an amicus brief supporting Anthropic's legal challenge against the Pentagon, arguing that a temporary restraining order is necessary to prevent disruption to suppliers relying on the AI company's technology. The brief, submitted to a federal court in San Francisco, was also signed by Google, Amazon, Apple, and OpenAI.
The dispute stems from collapsed contract negotiations over a $200m deal to deploy Anthropic's AI on classified military systems. Talks fell apart after Anthropic insisted its technology should not be used for mass surveillance of US citizens or to power autonomous lethal weapons. Defense Secretary Pete Hegseth subsequently labelled the company a supply-chain risk, a designation typically reserved for firms with ties to foreign adversaries.
Anthropic launched two lawsuits on Monday challenging the Pentagon's decision, arguing that the designation violates its First Amendment rights and is ideological punishment for its stance on AI safety. The company stated it does not have confidence that its AI system, Claude, would function reliably in lethal autonomous warfare.
Microsoft, a key Pentagon tech partner holding part of the $9bn Joint Warfighting Cloud Capability contract, stressed the need for reliable access to technology while ensuring AI is not misused. The Pentagon's chief technology officer has stated there is no chance of renegotiation with Anthropic.
