Is it not a crime to mistreat prisoners of war? Is it not a crime that FEPOWs in WWII were starved, beaten, raped, tortured and worked to death? Is it not a crime that they were forced to construct airstrips on far flung coral atolls where many went blind under the relentless equatorial sun? Is it not a crime that they were forced to clear immense tracts through dense woodland and to do backbreaking labour laying railroad track in disease-ridden jungles? Is it not a crime that they were forced to delve deep into the bowels of the Earth to mine zinc and other ore under unspeakable conditions? Is it not a crime that they were locked in the airless holds of the Hellships and left in pitch blackness without food and water for days as Allied ships and aircraft fired upon them, not knowing there were POWs aboard because the Japanese refused to distinguish vessels carrying POWS from the rest of the fleet? Is it not a crime that many were murdered and cannibalised, used for bayonet practice?
And what about what the Japanese did to the civilians living in the places they conquered? They ravaged and raped and slaughtered them like animals. They killed the young and the old. They bayoneted infants and gang-raped elderly women.
Let no one say that they got more than what they deserved.
That being said, the atomic bombs were not only useful as an incentive for the Japanese to surrender on the Allies' terms, their use also served as a warning to the Soviets that going in for a land grab in Western Europe or Japan would result in massive repercussions. Stalin got the message, and after the mushroom clouds cleared, Japan was whole. Had it not been for the atomic bombs, things would have been far, far worse for Japan in the long run.