Federal Appeals Court Backs Pentagon’s Anthropic AI Ban in Major Ruling

TLDR

• The U.S. Court of Appeals for the D.C. Circuit backed the Pentagon’s blacklisting of Anthropic in a 2-1 decision.
• Anthropic received a supply chain risk designation from the Pentagon in March 2026.
• Claude AI models remain prohibited from use by the Defense Department and its contractors.
• The court majority dismissed arguments that the Pentagon’s action violated constitutional protections or lacked proper justification.
• The AI company is weighing additional legal remedies, potentially including an appeal to the nation’s highest court.

The Pentagon’s blacklisting of Anthropic has been validated by a federal appeals court. The U.S. Court of Appeals for the District of Columbia Circuit issued its decision Friday.

In a split decision, judges Gregory Katsas and Neomi Rao sided with the government, while Judge Karen LeCraft Henderson offered a dissenting opinion.

At the heart of the dispute is the Defense Department’s March determination that Anthropic poses a risk to supply chain security. This classification typically applies to entities with connections to hostile foreign governments.

Under this ruling, the military is barred from deploying Anthropic’s Claude AI systems. Defense contractors are similarly prohibited from integrating Claude into Pentagon-related projects.

Origins of the Pentagon-Anthropic Conflict

The AI company had established partnerships with multiple federal agencies, including the Defense Department. A $200 million agreement was reached between Anthropic and the Pentagon in July 2025.

By September, negotiations had collapsed. Military officials sought unrestricted access to Claude for any legal military application. Anthropic pushed for safeguards that would prevent use in autonomous weapons systems and domestic spying operations.

No compromise could be reached. Defense Secretary Pete Hegseth claimed Anthropic was attempting to exercise veto authority over national security decisions.

In his written opinion, Judge Katsas referenced Hegseth’s concerns about AI systems experiencing unexpected failures. The secretary also expressed apprehension about potential manipulation of Claude. Anthropic has challenged these assertions.

Katsas concluded that weighing such security considerations falls within the authority of the president and defense leadership, not judicial oversight.

Anthropic’s Legal Path Forward

Earlier this year, Anthropic initiated legal proceedings in two federal jurisdictions. The company filed suit in San Francisco and separately in the D.C. Circuit.

Last month, a San Francisco judge determined that one aspect of the Pentagon’s designation violated federal law. That judgment stands independent of Friday’s appellate ruling and has not yet been challenged by the government.

Friday’s decision validated a different legal mechanism employed by the Defense Department. Since the two designations rest on distinct statutory foundations, the D.C. court’s opinion did not override the California judgment.

As a result, Anthropic retains limited ability to collaborate with certain government entities and contractors based on the California outcome. However, the Pentagon prohibition stays in effect.

In a post-ruling statement, an Anthropic representative expressed disappointment with the outcome.

“Another federal court has already held the government’s parallel designation unlawful,” the spokesperson said. “We remain confident in our position and are considering all options, including further review.”

The court has granted Anthropic a window before the decision becomes enforceable. The company may petition the same three-judge panel for reconsideration. Alternatively, it can request an en banc review before all active D.C. Circuit judges.

An appeal to the Supreme Court also remains an option.

Tensions between Anthropic and the Trump White House have escalated over recent months. President Trump has repeatedly targeted Anthropic CEO Dario Amodei in public statements on social platforms.

Emil Michael, Pentagon Undersecretary, praised Friday’s outcome on social media. He stated the ruling ensures that no private corporation can dictate military operations.

Anthropic has yet to announce its next legal move.