The U.S. Department of Defense has begun engineering work to replace Anthropic's Claude AI across its systems after labeling the company a supply-chain risk, while Anthropic sues the Pentagon in federal court challenging the unprecedented blacklist.

Microsoft filed an amicus brief in federal court supporting Anthropic's lawsuit against the Pentagon, urging a judge to issue a temporary restraining order blocking the DOD's supply chain risk designation and warning the ban could 'hamper U.S. warfighters' by disrupting AI systems already in use.