I listened to a Vox’s Today Explained that tackled this whole contract. What was said on there was that Anthropic had in some very minor stipulations about AI and war, but were rejected. OpenAI came in with their offer and then after getting it, the contract they signed had the wording that Anthropic was asking for.

It basically came down to, Altman was the favorite of the Trump administration and got the contract because of behind the scenes bullshit and because Dario was/is super critical of Trump when it comes to AI safety.