If the Pentagon carries out its threat to blacklist Anthropic’s Claude AI platform, it could be three months or even longer before the U.S. military regains access to such a powerful tool on its classified networks, according to multiple sources familiar with the fight between the Defense Department and the AI maker.

If the Pentagon does designate the San Francisco-based AI startup as a supply-chain risk, it would touch off a lengthy and likely expensive series of protective measures, the people familiar said.

Operators would have to reconfigure data inputs that they are feeding into models, re-examine how to share data in real-time with the intelligence community which also uses Claude widely, and re-validate that replacement models were functioning as the military expected it to, they said.

In July, Anthropic received a $200 million contract to provide its frontier-model tools to the Pentagon, as did the other three U.S. makers of such products: OpenAI, Google, and xAI.