You seem to be misunderstanding the facts. Claude was already used by the US Military, under an existing contract between Anthropic and the US Department of War.
The core dispute was the US Military deciding it needed to renegotiate this contract, but without Anthropic's two red lines: No fully autonomous weapons (i.e., zero humans in the loop), and no mass domestic surveillance.
The DoW actually used AI in the Iran war, which led to them attacking a school and killing more than a hundred childrem. That's exactly what Anthropic wanted them to prevent. https://www.bloomberg.com/graphics/2026-iran-school-attack/