From wiki
“The Target Committee nominated five targets: Kokura (now Kitakyushu), the site of one of Japan’s largest munitions plants; Hiroshima, an embarkation port and industrial center that was the site of a major military headquarters; Yokohama, an urban center for aircraft manufacture, machine tools, docks, electrical equipment, and oil refineries; Niigata, a port with industrial facilities including steel and aluminum plants and an oil refinery; and Kyoto, a major industrial center. The target selection was subject to the following criteria:
The target was larger than 4.8 km (3 mi) in diameter and was an important target in a large city.
The blast wave would create effective damage.
The target was unlikely to be attacked by August 1945.[73]
These cities were largely untouched during the nightly bombing raids, and the Army Air Forces agreed to leave them off the target list so accurate assessment of the damage caused by the atomic bombs could be made. Hiroshima was described as “an important army depot and port of embarkation in the middle of an urban industrial area. It is a good radar target and it is such a size that a large part of the city could be extensively damaged. There are adjacent hills which are likely to produce a focusing effect which would considerably increase the blast damage. Due to rivers it is not a good incendiary target.”[73]
The Target Committee stated that “It was agreed that psychological factors in the target selection were of great importance. Two aspects of this are (1) obtaining the greatest psychological effect against Japan and (2) making the initial use sufficiently spectacular for the importance of the weapon to be internationally recognized when publicity on it is released. ... Kyoto has the advantage of the people being more highly intelligent and hence better able to appreciate the significance of the weapon. Hiroshima has the advantage of being such a size and with possible focussing from nearby mountains that a large fraction of the city may be destroyed. The Emperor’s palace in Tokyo has a greater fame than any other target but is of least strategic value.”[73]
Edwin O. Reischauer, a Japan expert for the U.S. Army Intelligence Service, was incorrectly said to have prevented the bombing of Kyoto.[73] In his autobiography, Reischauer specifically refuted this claim:
... the only person deserving credit for saving Kyoto from destruction is Henry L. Stimson, the Secretary of War at the time, who had known and admired Kyoto ever since his honeymoon there several decades earlier.[74][75]
Extant sources show that while Stimson was personally familiar with Kyoto, this was the result of a visit decades after his marriage when he was governor-general of the Philippines,[76] not because he honeymooned there.[77][78] On 30 May, Stimson asked Groves to remove Kyoto from the target list due to its historical, religious and cultural significance, but Groves pointed to its military and industrial significance.[79] Stimson then approached President Harry S. Truman about the matter. Truman agreed with Stimson, and Kyoto was temporarily removed from the target list.[80] Groves attempted to restore Kyoto to the target list in July, but Stimson remained adamant.[81][82] On 25 July, Nagasaki was put on the target list in place of Kyoto. It was a major military port, one of Japan’s largest shipbuilding and repair centers, and an important producer of naval ordnance.”
I have gone from an enthusiastic backer of our employment of nuclear weapons to a guy who wonders if we went too far. I worked in the field of underground nuclear weapons testing 40 or so years ago and later worked in the Threshold Test Ban Treaty verification field as a military officer - so I have some time reviewing the true nastiness of these weapons.
Last bunch of years, I've read the histories for and against using the nukes but most of them gloss over other potential employments we could have done instead of deliberately targeting civilians:
1. The Demonstration. Notifying the Japanese government that we have a new catastrophic weapon, and we will use the first one to destroy the fleet anchorage at Hashirajima - and do it quickly before any fleet units can disperse.
2. Attack the major army headquarters for the 16th Army. It would decapitate the critical leadership and staffs to oppose our planned landings on Kyushu and would demonstrate the true power of the bomb to the Japanese leadership.
Then, when they continued to fight, we'd be more justified in attacking a true industrial center - not an "Untouched" city, filled with noncombatants, that would be used as lab for experimentation.
One of you mentioned Dresden. It as an example of how we lost our decency in our war against indecency.