I think it was a combination of many things, but back then there still was a bit more room for black and white view about the different counterparts in the wars. I don't think anyone sane would think what Hitler, Stalin or Mao did was good. Especially the latter killed their own people too and so many of them. For what, power, ideology?
War is business and for United States war has always been a part of the foundation of your country. Pilgrims from Europe settling to a new country, then there were the slaughters of the natives, slavery and of course the Civil War. That's hell of a lot of messy and tangled karmic stuff, but I make necessarily no judgements. Just observations of history. So much mixed energies there and lots of differences.So the Nazis were evil, right? Well, yes, they did some horrific things for sure. And the U.S. was the knight in shining armor come to save the day we're repeatedly told. Here's how I look at that one. When Hitler invaded Poland in 1939, it had only been 49 years since the "Wounded Knee Massacre" in 1890 that finally brought on the bitter end of that terrible genocide. That's a mighty fast remaking of an image. Public Relations is not a new thing!
The Japanese were brutal in combat and they had own sadistic methods of torturing people, Russians were experts with slaughters and the Gulags, Germans showed their inhumanity with their concentration camps and so forth. The way I see it, dropping or testing the atom bombs in those Japanese cities was a war crime and I don't think I'm alone with that view. There was an "excuse" for it, but I don't think it's justification. It got the point across, but it was brutal and sickening. Man and scientists had finally perfected warfare and technology to the point that it can unleash the power of the Sun here on Earth. As J. Robert Oppenheimer witnessed the first nuclear explosion in New Mexico he was reminded of the famous words in the Bhagavad Gita: "Now I am become Death, the destroyer of worlds."The world will never be allowed to forget atrocities committed the Russians, Germans and Japanese; but U.S. atrocities (Hiroshima and Nagasaki anyone?) is never a part of that conversation. For that matter, imagine if a guy named Stalin or Hitler had been overseer of the "Wounded Knee Massacre" and all that entailed. Hell, we'd still not be hearing the end of it...
It was time for United States to become that Death and unleash hell in the land of the Rising Sun.
Of course the firebombing of Tokyo caused hell of a lot victims too and that campaign was already devastating enough. In war there really is no beauty, it's just legalized murder and civilians such as women and children get to experience it too. The PR department of US had things going pretty well all the way until Vietnam and then people finally started to wake up more and see that war ain't actually so great after all. Who are the good and bad guys after all?
More wars came after that of course as they were needed, but there were even less justifications for them. Yet the spin doctors always somehow managed to bamboozle the people and make them believe that war is good and favorable for the country, it's good for the economy too right? In that the presidents played their part too.
The new Roman Empire was only expanding, even moreso after the fall of their greatest enemy, the Soviet Union. Since early 90's United States had virtually the whole world as it's own playgroung. That's always the thing with empires, they always want total domination over the globe. It will be either trough having "allies" (vassal states) or enemies who will of course suffer the consequences of war. USA has always had the need for an external enemy so that it's own people wouldn't have enough time to look at the internal problems which have been only growing more, like an internal rot inside a huge tree. Yet we all know what happened to the Roman Empire with it's Caesars.