On March 9, Anthropic filed suit in federal court to stop the Department of Defense from placing the artificial intelligence company on a national security blacklist. The complaint names the U.S. government, President Donald Trump, Defense Secretary Pete Hegseth and additional officials, and sets out multiple legal theories for why the agency action and related directives are unlawful.
The company’s filing lays out four principal claims, each tied to a different legal statute or constitutional protection. Anthropic argues that the DOD’s move to label the firm a supply-chain risk and to block the department’s contractors, suppliers and partners from engaging in commercial activity with the company was unlawful and procedurally deficient.
First Amendment violation
Anthropic asserts that the Pentagon’s actions amount to retaliation for constitutionally protected expression. The complaint states the company has a right under the First Amendment to speak publicly and privately to government officials about the limits of its own AI services and matters of AI safety. According to the suit, the government’s blacklisting constitutes retaliation against Anthropic’s expressive activities, including protected speech, viewpoints and petitioning of the government.
Presidential action beyond legal authority
The complaint argues that a presidential directive to halt government work with Anthropic - announced in a post on President Trump’s social media platform late last month - was "ultra vires," meaning it exceeded the president’s legal power and authority. The filing frames that public direction as an element of the government conduct Anthropic seeks to enjoin.
Fifth Amendment due process claims
Anthropic contends the government violated its due process rights under the Fifth Amendment by effectively blacklisting the company without observing required legal protocols. The lawsuit alleges the government terminated existing contracts and blocked future work without providing prior notice or a meaningful opportunity for Anthropic to respond, bypassing mandatory procedural safeguards.
Administrative Procedure Act violation
The complaint challenges the DOD’s designation of Anthropic as a supply-chain risk under the Administrative Procedure Act (APA). Anthropic argues that the designation and the resulting prohibition on commercial relationships with DOD contractors, suppliers and partners failed to follow the APA’s procedural requirements and should be subject to judicial review. The filing asserts Defense Secretary Pete Hegseth exceeded his authority, did not adhere to proper legal procedures and lacked supporting evidence for the supply-chain risk finding.
The lawsuit seeks to block the government actions described in the filing and to have the court review the legal and procedural bases for the DOD’s determination. The complaint presents the company’s view that the steps taken against it interfere with constitutional rights and statutory procedures, and requests relief consistent with those claims.
Because the suit centers on constitutional protections, administrative law and the question of executive authority, it raises issues affecting government procurement relationships and the ability of defense-related contractors, suppliers and partners to engage with a private AI developer whose services the government has moved to restrict.