Anthropic probably made the mistake of questioning the Military's activities related to Claude after the Venezuela mission and wanted reassurance that the model wouldn't be used for the redlines, and the military didn't like this and told them we aren't using your models unless you agree to not question us and then the back and forth started.
In the end, we will probably have both OpenAI and Anthropic providing AI to the military and that's a good thing. I don't think they will keep the supply chain risk on Anthropic for more than a week.