Pentagon responds to Anthropic suit arguing the company is a 'substantial risk' to national security

• In a new filing, the Department of Defense outlined its arguments against Anthropic's contract lawsuit.
• The DoD says Anthropic's refusal to accept the government's contractual terms is not protected speech.
• The government says Anthropic poses a "substantial risk" to the supply chain and national security.

The US government is urging a federal judge to reject Anthropic's bid to reverse its status as a supply chain risk.

In a court filing Tuesday, lawyers for the Department of Defense said federal agencies acted lawfully when they moved to phase out Anthropic's technology after the company refused to agree to contract terms allowing "any lawful use" of its AI by the military. The Pentagon said that the company poses a national security risk.

The dispute centers on a broader clash between the military's use of AI and the contractual safety limits it sets with the tech providers.

Anthropic, which builds the Claude AI model, sued the government after President Donald Trump ordered government agencies to stop using Anthropic's technology, and the Department of Defense labeled the company a "supply chain risk," effectively barring it from holding federal contracts. The company argued the move was unlawful retaliation tied to its safety policies.

The government, in turn, said it is simply exercising its authority to choose vendors — and that Anthropic's restrictions and behavior made it an unacceptable partner for national security work.

Representatives for the Department of Defense did not immediately respond to requests for comment from Business Insider.

According to the filing, the conflict escalated after Anthropic declined to modify its usage policies, which restrict certain applications like weapons development and surveillance. Officials said those limits could give a private company undue influence over military operations and decision-making.

The government also argued that Anthropic's role as the developer and maintainer of its AI systems creates inherent risks. Because such systems require ongoing updates and tuning, officials warned the company could "subvert the design and/or functionality" of its tools or alter performance during critical operations.

"We are reviewing the government's filing and look forward to presenting our response to the court," the company said in a statement. "As we shared last week, seeking judicial review does not change our longstanding commitment to harnessing AI to protect our national security, but this is a necessary step to protect our business, our customers, and our partners."

Anthropic has argued that the actions violate its First Amendment rights and due process protections. However, the government pushed back, arguing the dispute is about commercial conduct — not protected speech — and that agencies are free to decide "those with whom [they] will deal" in procurement.

The filing also dismisses Anthropic's claims of irreparable harm, describing potential business losses as "speculative" and arguing that any damages could be addressed through contract remedies.

A hearing on Anthropic's request for a preliminary injunction is scheduled for March 24 in federal court in San Francisco.