Very interesting to note that Hiroshima had never been bombed — until August 1945 — despite its military and industrial infrastructure.
Obviously the city was “targeted” to measure the level of destruction on buildings and humans an A-bomb can accomplish.
Dresden is a different story. It was a gleeful act of destruction of Christian life and Christian civilization by non-Christian leaders in DC, London (and Moscow).
According to General Leslie Grooves, Kobe was the first pick for nuclear destruction, but the secretary of state vetoed that idea because it was one of his favourite historical tourist destination. See “Now It Can Be Told”
Maybe he was referring to the “entire population” part. The total population of Hiroshima at the time of the bomb is said to have been 350K. The bomb killed about 80K instantly. 10s of thousands died later of radiation poisoning. Your “total kill” is a gross exaggeration. It was less than a third.
The fact it had not been bombed before was one of the main reasons for selecting it as a target since this was the first use of an Atomic bomb and they wanted the world to see just how devastating even a single atomic bomb could be on a city that was completely untouched prior by the war.
I just presumed that the destruction of an entire city would kill the entire populace, because they wouldn’t have had time to seek shelter/ As to the numbers; I’d guess the population of Hiroshima was more than Dresden. Nor do I know how the ‘less than a third’ could have been arrived at, because those who eventually died from severe burns would have added to the fatalities. But we’re splitting hairs here - the topic is the morality of the bombing of the city, not the casualties tally.