So not to sound like I fully support the bombings, but they did touch in the movie about why it was a good thing. To save not only hundreds of thousands of American soldiers who would have invaded mainland Japan, but also the (potentially) greater amount of Japanese soldiers and citizens that would have died too. Millions to die because conventional war tactics weren't enough to scare the Japanese.

They were hard-core. They took the fire bombings (which had killed many more than the nukes) in stride. They raped Nanking with unimaginable horrors. Countless human atrocities in the name of "science"

The Japan of today in not the Japan on WW2. There's a good amount of people who would say the nukes were a merciful way to end the war. The US, in prep for the mainland assault, made the amount of purple hearts they thought they would need for just the wounded. Since the assault never happened, we still hand them out to this day