Anthropic PBC v. U.S. Department of War

On 9 March 2026, Anthropic filed suit against the United States Department of War and sixteen other federal agencies and their heads. Claude is described as the Department of War's most widely deployed frontier AI model and the only such model operating on its classified systems.

The dispute arose from negotiations in late 2025 over a new agreement to deploy Claude on the Department's GenAI.mil platform. The Department requested that Anthropic remove its usage policy and permit all lawful use of Claude. Anthropic agreed, subject to two restrictions: a prohibition on use for lethal autonomous warfare without human oversight, and a prohibition on mass surveillance of Americans. The Complaint contends these restrictions reflect Anthropic's genuine assessment of Claude's current technical limitations and safety profile, not ideological obstruction.

In February 2026, the Department publicly responded with an ultimatum demanding Anthropic comply by 5:01 p.m. on 27 February 2026 or face either designation as a supply-chain risk or compelled compliance under the Defense Production Act. Anthropic's CEO declined to abandon the two restrictions, following which the Executive Branch acted. On 27 February 2026, President Trump posted a directive on social media ordering every federal agency to immediately cease all use of Anthropic's technology. Hours later, Secretary Hegseth posted a Secretarial Order via social media designating Anthropic a supply-chain risk to national security and directing that no contractor, supplier, or partner doing business with the U.S. military could conduct any commercial activity with Anthropic. A formal letter to Anthropic followed on 4 March 2026, referring to the designation, and that that exercising the authority granted by 10 U.S.C. § 3252 against Anthropic is “necessary to protect national security.” Multiple agencies including the General Services Administration, the Department of the Treasury, the Department of State, and the Federal Housing Finance Agency subsequently terminated or suspended their use of Anthropic's services. The Complaint notes that senior Department officials confirmed to the press that the designation was ideologically driven and that there was no evidence of actual supply-chain risk.

The Complaint asserts five causes of action: that the Secretary of Defense's actions (the Secretarial Order and letter of 4 March)(the "Challenged Actions") were arbitrary, capricious, and in excess of statutory authority under the Administrative Procedure Act and 10 U.S.C. section 3252; that the Challenged Actions constituted unlawful retaliation against protected speech and petitioning activity in violation of the First Amendment; that the Presidential Directive exceeded the President's constitutional and statutory authority; that the Challenged Actions violated the Fifth Amendment's Due Process Clause by depriving Anthropic of reputational, contractual, and liberty interests without notice or meaningful process; and that the agency orders implementing the Presidential Directive were issued without statutory authorisation under 5 U.S.C. section 558.

Anthropic contends that the Challenged Actions have caused immediate and irreparable harm, including cancellation of federal contracts, jeopardy to hundreds of millions of dollars in private sector revenue, and lasting damage to its reputation and First Amendment freedoms.

Anthropic seeks declaratory relief, a permanent injunction, rescission of all implementing directives, and an award of costs and attorneys' fees.