The U.S. Department of Defense said on Tuesday evening that Anthropic poses an “unacceptable risk to national security,” marking the agency’s first rebuttal to the AI lab’s lawsuits challenging Defense Secretary Pete Hegseth’s decision last month to label the company a supply-chain risk. As part of its complaints, Anthropic had requested the court temporarily block the DOD from enforcing its label. The crux of the DOD’s argument, made in a 40-page filing in a California federal court, is the concern that Anthropic might “attempt to disable its technology or preemptively alter the behavior of its model” before or during “warfighting operations” if the company “feels that its corporate ‘red lines’ are being crossed.” Anthropic last summer signed a $200 million contract with the Pentagon to deploy its technology within classified systems.…