There are fierce battles over principles, and then there are grudge matches. In recent days, Anthropic has engaged in an extraordinary mix of both.

For over a week, the AI startup and its CEO, Dario Amodei, have been locked in an intense struggle with the Pentagon over Anthropic's refusal to let the military use its technology for domestic surveillance and to control autonomous weapons systems. The Pentagon on Wednesday took the unusual step of designating Anthropic a "supply chain risk," which will cut it off from military uses of its technology. Anthropic has vowed to challenge the move in court.

All the while, Amodei kept his cool in public, even as Emil Michael, a top Pentagon official, blasted him on X as a "liar" and said he had a "God-complex." Inside Anthropic, though, Amodei didn't display the same diplomatic demeanor. On Wednesday, The Information broke the news of a fiery 1,600-word memo Amodei sent to Anthropic employees last Friday about the conflict with the Defense Department, in which he described Anthropic's biggest rival, OpenAI, and its CEO, Sam Altman, in deeply unflattering terms.