The U.S. is the most powerful nation in the world. We have an unprecedented capacity to destroy organized state power. It is naive to think that the first steps toward international accountability for world leaders would feasibly start with or initially include the U.S.
It's naive to think it's steps in that direction at all. The steps needed would include the whole world putting economic sanctions on the US and stopping them only when the US gives up all its war criminals just like Serbia did.
It is a step in the right direction because we are talking about it. The idea of a world leader being accountable for evil acts it now no longer as absurd as it was in 1900. Hopefully, soon, more and more people will wonder why U.S. leaders aren't similarly held accountable. It will be a good thing when that happens.