Not true. We could have avoided INTENTIONALLY killing thousands of babies and little old ladies (thus violating the ancient rules of war) AND avoided an invasion had Truman agreed at the outset to a conditional surrender in which the Japanese could keep the emperor. That was the sticking point prior to the bombs. Ironically, despite the A Bombs the Japanese held out for keeping the emperor and Truman finally agreed (thus overruling his hardline New Deal advisors).
So at the time, the US saw two viable options 1) invasion or 2) dropping the bomb. I’m glad they went with two. Hindsight is 20/20.
I don’t believe that this is true. The Japanese surrender was unconditional.