The Japanese army was extremely ruthless in WWII. Two excellent examples would be the Rape of Nanjing, and the Bataan Death March. Once the Japanese conquered Nanjing, the soldiers murdered the men and raped the women and children. Ones kept alive were beat to death or used for bayonet practice. This inhumane treatment was also present in the Bataan Death March. After the American and Filipino fighters surrendered to the Japanese Imperial Army in Bataan, they were forced to trek to Balanga, the capital of Bataan. They received very little water and scarcely any food during the long, excruciating walk. Many Americans and Filipinos died from exhaustion on the way, while some were simply massacred. Once the survivors reached the prisoner camp in Balanga, diseases spread quickly due to poor hygiene and it was extreme crowded. These two incidents were deemed war crimes by the Allies, as both represented horrible atrocities that clearly violated human rights.
On the other hand, there are reasons as to why the bombing of Japan was not justified. The first one would be that Japan was ready to surrender, even before the dropping of the first atomic bomb at Hiroshima. As long as the Japanese could keep their emperor in power, their sacred idol, they would completely surrender. From this, it is clear to see that the emperor wanted peace. America did not accept this deal, and thought that the atomic bomb would "force" them to surrender. Unfortunately, they did not surrender even after two atomic bombs were dropped. Japan surrendered after the invasion of the Soviet Union. The second and final reason was that the bombing was targeted largely at civilians. Civilians are people who do not participate in wars. They were not the one that committed the atrocities. As a result, why bomb them? Survivors suffered scars for the rest of their lives, if they didn't die of the radiation exposure in the first place.
Now, some people may argue that it was justified. Initially, it seemed justified for me as well. Japanese people slaughtered, tortured, and raped soldiers and civilians alike. Is it not only logical and fair that the Japanese people be treated the same way, as they treat others? Realistically, this is war, and it is called "revenge". I think the realistic part of me longs to accept this reason. Imagine being stabbed multiple times after a long walk under the scorching sun without water or food, and being left behind to die. Or as a woman, imagine being beaten until you're almost dead, and then raped. Or as parents, watching Japanese soldiers ruthlessly stabbing your newborn baby to shut them up. How could we not feel hate and anger to the atrocities committed by the Japanese people? However, one reason managed to convinced me, and this is seen all around the world. Though you commit this act to avenge your allies, aren't you committing the same atrocities as your enemies? You condemned your enemies' actions, but in the end you're just mimicking them. Doesn't that make you just as horrible? Simply ironic and hypocritical. This reason was the decisive moment. Without acknowledging how ironic America was, always droning on and on about peace, I would have agreed to the fact that the bombings were justified. But in the end, the bombing was not justified because the civilians took the main damage, despite not being the one who committed the atrocities, the Japanese were ready to surrender, and the fact that America was extremely ironic as they condemned these atrocities, but committed atrocities themselves.