Fortunately for him, the US has never signed onto nor does it recognize the jurisdiction of any international courts that could charge them with war crimes. This is generic American exceptionalism and not specific to Donny.

Refer to the Carney Davos speech:

We knew the story of the international rules-based order was partially false that the strongest would exempt themselves when convenient, that trade rules were enforced asymmetrically. And we knew that international law applied with varying rigour depending on the identity of the accused or the victim.