How did the events of WWII create strong opposition to future war crimes?

World War II was the deadliest military conflict in history in terms of total dead, with some 75 million people casualties including military and civilians, or around 3% of the world's population at the time. Many civilians died because of deliberate genocide, massacres, mass-bombings, disease, and starvation.

kind of thinking it would be c hope this out

the hereditary right of a monarch to rule from the mandate of heaven