Microsoft and a group of retired military leaders are backing Anthropic, asking a federal judge to block the Trump administration’s designation of the artificial intelligence company as a supply chain risk.
In a legal filing, Microsoft challenges Defense Secretary Pete Hegseth’s actions last week to bar Anthropic from military business by labeling its AI products as a threat to national security.
So did a group of 22 former U.S. military officials, including the heads of the Air Force, Army and Navy, and the chief of the Coast Guard. In their own court filings, they argue that Mr. Hegseth’s actions amount to an abuse of government power to “retaliate against private companies that have displeased the leadership.”
The Department of Defense has filed a lawsuit against Anthropic following an unprecedented public controversy over Anthropic’s refusal to allow unrestricted military use of its AI model, Claude. President Donald Trump also said he would order all federal agencies to stop using Claude.
“Using supply chain risk designations to address contract disputes can have serious economic consequences that are not in the public interest,” major government contractor Microsoft said in a filing in San Francisco federal court on Tuesday, and Anthropic sued the Trump administration on Monday.
The Pentagon’s action “forces government contractors to follow vague and unclear directives that have never before been publicly exercised against a U.S. company,” Microsoft’s legal brief said.
They are asking a judge to temporarily lift the designation so Antropic and the Trump administration can have a more “rational discussion.”
The Pentagon declined to comment, saying it does not discuss litigation matters.
Microsoft’s filing also expressed support for Anthropic’s two ethical red lines, which stalled contract negotiations after the Pentagon insisted the company be allowed “all lawful” uses of AI.
“Microsoft also believes that U.S. AI should not be used to conduct mass domestic surveillance or start war without human control,” the company said. “As the government acknowledges, this position is consistent with the law and widely supported by American society.”
The software giant’s court filing follows other lawsuits in support of Anthropic, including those from AI developer groups Google and OpenAI, and from groups such as the Cato Institute and the Electronic Frontier Foundation.
A fourth similar application was filed by a group of retired military leaders, including Michael Hayden, a former CIA director and retired Air Force general, and Thad Allen, a retired Coast Guard general who led the government’s response to Hurricane Katrina.
“Far from protecting the national security of the United States, the Secretary’s actions here threaten the rule of law principles that have long strengthened our military,” the filing states.
U.S. District Judge Rita Lin is presiding over the case in federal court in San Francisco, where Anthropic is headquartered. Anthropic also filed a separate, narrower lawsuit in the Federal Court of Appeals in Washington, D.C.
Lin was nominated by President Joe Biden to serve on the court in 2022 and has a hearing scheduled for March 24.
Neither legal filing mentions the Iran war, which began shortly after Trump and Hegseth announced they would punish Anthropic, but former military officials warned that the “sudden uncertainty” of targeting technology widely integrated into military platforms could disrupt plans and put soldiers at risk during ongoing operations.
The current commander of U.S. Central Command acknowledged in a video posted on social media Wednesday about the U.S. attack on Iran that the military is using “sophisticated AI tools” to “sift through vast amounts of data in seconds,” but he did not specifically name which tools.
Admiral Brad Cooper said that while these AI tools are allowing leaders to make smarter decisions faster, “humans will always make the final decision on what to shoot, what not to shoot, and when to shoot.”
Until recently, Anthropic was the only company in its industry approved for use in classified military networks. But as a result of the conflict, military officials said they were considering transferring that work to competitors Google, OpenAI and Elon Musk’s xAI.
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Associated Press writer Konstantin Tropin contributed to this report.
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