I don't know what type of revisionist book you got your information from, but it's been estimated from 120,000-230,000 innocent Japanese civilians died from the nuclear attacks. It's in cold blood because we weren't discriminate in attacking the military forces/infrastructure... we used a nuclear bomb that would end lives over a wider area instead of more discriminate precision bombing.
Your insistence that a second atomic bomb "had" to be used is really a matter of opinion. An opinion that is slowly shifting as you know from our other discussion. Nevertheless, finding a "need" to kill civilians in cold blood sets an insanely dangerous precedent for future conflicts.
You also ignored the question and did verbal gymnastics. No one truly believes it "depends on the circumstances" to label the atomic bomb as an indiscriminate bomb. The bomb either discriminately or indiscriminately takes lives... Do you know the definition of "discriminate" and "indiscriminate"? If so, then you would know the presumed necessity to use the bomb to "saves lives and end the war" would not have ANY relevance to the bomb being either discriminate or indiscriminate. The need for a bomb doesn't make a bomb discriminate or indiscriminate in other words. Just as the color someone paints a bomb has no relevance to it being an ideal bomb to discriminately or indiscriminately kill armed forces. "Color" and "need" are irrelevant external factors that do not change the label to "discriminate" or "indiscriminate".