Yes, Musk is guilty of treason for exactly that reason. He directly sabotaged a major US military operation in Ukraine.

However, the military is bound by US and international law. It's clear they're not going to obey either of those with respect to this contract.

On top of that, Anthropic has correctly pointed out that the use cases Trump was pushing for are well beyond the current capabilities of any of Anthropic models. Misusing their stuff in the way Trump has been (in violation of the contract) is a war crime, because it has already made major mistakes, targeted civilians, etc.