A federal judge in Washington, D.C., has dealt a significant setback to the Pentagon’s effort to sideline Anthropic from federal use, ruling that the government’s actions were “illegal and baseless” and temporarily blocking parts of the administration’s campaign against the AI company.

While the full factual record will matter as the case proceeds, the court’s language is notable.

A federal judge in California has ruled for Anthropic in its challenge to the Pentagon’s decision to designate the AI company as a supply-chain risk, concluding the government’s action was unlawful and effectively preventing the blacklisting from taking hold. The dispute puts a spotlight on one of the most consequential fault lines in modern procurement law: how far the government can go in invoking national-security concerns to cut off a contractor — or potential contractor — from federal business.

At the center of the case is the Defense Department’s asserted authority to restrict access to the federal marketplace based on perceived risk.