The US government has defended its decision to blacklist Anthropic, the maker of AI assistant Claude, in court. The move comes after Defense Secretary Pete Hegseth and President Donald Trump accused Anthropic of endangering American lives with its restrictions on the use of its products. Anthropic had refused to remove guardrails around its technology for use in autonomous weapons or domestic surveillance. The Pentagon separately designated Anthropic a supply chain risk under a different law, which could extend the order to the entire government. The company is challenging this decision in a second lawsuit.