Microsoft Urges Courts to Halt Pentagon Ban on Anthropic’s AI

Overview

• Microsoft filed amicus briefs on March 10 in federal courts in California and Washington, D.C., asking judges to suspend the Pentagon’s supply‑chain risk designation for Anthropic.
• The filing seeks an injunction that would reopen talks, with Microsoft calling the Pentagon’s actions “drastic” and “unprecedented” and warning of broad negative consequences.
• Defense Secretary Pete Hegseth’s department labeled Anthropic a supply‑chain risk and directed federal agencies to stop using the company’s Claude assistant.
• The dispute followed Anthropic CEO Dario Amodei’s restrictions forbidding use of its models in lethal autonomous weapons and mass domestic surveillance, which derailed contract talks.
• More than 30 researchers affiliated with Google and OpenAI, including Jeff Dean, publicly backed Anthropic, and the White House and Pentagon had not issued public responses at the time of reporting.