Japan killed tens of millions of Chinese and intended to occupy the entire western Pacific, killing or enslaving all the people who lived there. The entire nation, all of its labor and industry, was bent toward this goal. It was a nation of profound evil.

That wouldn't be far from the truth? If I remember, and it was reported correctly, the US govt deemed the nuclear bomb to be the lesser of two evils; the other being a long drawn out deescalation due to Japanese pride.