As horrible as dropping a nuclear bomb was, it did save the Japanese people untold death and misery.
One must remember that in 1945, the atomic bomb was just a big bomb.
We today, having a history of the nuclear arms race and the decades of fearing a pending worldwide destruction, have a different perspective. American leaders in 1945 did not understand that this technology could lead to doom....it was just a big bomb that could destroy a small city and after all, we were dropping millions of bombs and destroying many cities.
The Soviet threat was very real. We had allied with the USSR to defeat Fascism...but we understood that they were a dangerous ally. We had helped Stalin complete his Trans-Siberian railroad and he had millions of soldiers and tanks and guns that he was moving to "help us" fight Japan with.....hoping to further expand Communist totalitarianism and probably jump into the Chinese war helping Mao as well.
Also, while we were bombing Japan at will after defeating the Japanese Navy and air defenses, we had not even engaged with the main force of the Imperial Army, who had a couple of million well-armed and experienced soldiers on the ground in China. So there was a large, veteran and fanatical Army of at least two million men who we had not even fought yet and who would have gotten to Japan to defend their country even if they had to get there on bamboo rafts. This is not to mention the Army and civilians who would have fought a ground invasion with whatever they had. Just this threat could have easily cost a million Japanese lives and probably a half million allies lives and would have lasted two more years.
Yes, the bomb was horrible, but in the long run it was also humane and prudent, saving millions of lives and saving Japan from decades of brutal Communist totalitarianism.