“... it is instructive to look at a map of where Nagasaki and Hiroshima are located. Both are at the very south of Honshu... as far away from the main population centers as they could be ...” [imardmd1, post 8]
There are no cities far from others in Japan, and there weren’t in 1945 either.
The 509CG crews had orders to deliver the atomic bombs by visual aiming only; on the strike mission of 9 August 1945 their primary target of Kokura was obscured by clouds. They flew on to Nagasaki, where they found more clouds; the bombardier managed a quick peek through the visual sighting system and dropped the weapon. Bockscar barely made it back to an Allied-held airfield on Okinawa: fuel trapped in an auxiliary tank curtailed their endurance.
The master targeting plan for B-29 strikes on Home Island cities was carefully arranged to spare some urban areas, but planners weren’t told why. The reason was to keep some targets undamaged, to test the limits of the destructive capacity of any weapon that the Manhattan Project might come up with.
Six hundred miles from Nagasaki to Tokyo. That soungs like a pretty fair distance to me. There is nothing further southwest than the ocean. Five hundred from Hiroshima to Tokyo. But maybe you didn't look at the map as was suggested.
Just stating facts. Not looking for an argument. I had to fly from Narita to Kagoshima on business, a 747 was used to handle the crowd of passengers.