I don't think dropping the atomic bomb on Hiroshima and Nagasaki was either necessary or acceptable. Japan was already weakened by the war and it was obvious that it wouldn't be able to fight much more. That's why America had other options to choose from in order to end the war other than the atomic bomb. However, I don't think their dropping the atomic bomb had much to do with Japan - it was just a demonstration of the US power and a threat to other countries in the world not to mess with it - Japan just happened to be the guinea pig. The atomic bomb led to the deaths of more than 200,000 people in Japan, and to dire consequences in Hiroshima and Nagasaki which can be still felt today, over 70 years since the bombing happened.