Even before WW2 most of their conflicts were on the wrong side of history. And if you analyze the actual system flows of WW2, there's an argument to be made that the US was only accidentally on the right side of history in WW2 and that the overarching strategic goals of the US in the conflict (anti-communism and dominance over Europe) were and are on the wrong side of history.
I'm not sure the US has ever been on the moral high ground when it comes to wars.
In fact, it's pretty hard to think of a war since WW2 where US was on the right side of history.
Even before WW2 most of their conflicts were on the wrong side of history. And if you analyze the actual system flows of WW2, there's an argument to be made that the US was only accidentally on the right side of history in WW2 and that the overarching strategic goals of the US in the conflict (anti-communism and dominance over Europe) were and are on the wrong side of history.