The bomb was VERY justified.
1 million men were estimated to have been killed in a full scale invasion of Japan. Those men would be someone's son. Someone's bothers. Someone's husband or boyfriend. The atomic bomb would definitely end the war. Try to explain the fact you had something that would end the war to the 1,000,000 mens' loved ones but their son, brother, or husband had to die. 100,000 civilian casualties didn't come anywhere near the amount of casualties there would have been in a full scale invasion of the country, and that's without including the number of Japanese that would have been killed and civilians. It also doesn't come any where near the amount of civilians murdered in the Holocaust.