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What were the reasons that the U.S. government selected Hiroshima to be the city in Japan on which the first atomic bomb was dropped, other than the obvious reason that Hiroshima was a large, important port of Japan?

What I mean is, what set Hiroshima, and, later, Nagasaki, apart from other important Japanese cities, making these two cities those selected for the atom bomb?

Could the reason have something to do with the city's location (near the coast in southern Japan); their industries; or some other factor, such as, perhaps, the location of important government offices there?

Although I did extensive research on this subject, the only reason I found for this was that, on the morning scheduled for the bombing, Hiroshima had no cloud cover, letting the bomber Enola Gay aim the bomb carefully. However, this is a short-term reason, and I'm looking for longer-term reasons.

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4 Answers 4

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A critical part of developing any weapon of war is to analyze how effective it is at destroying the enemy's ability to fight. This result can be gained from many different angles, one such being a psychological attack to cripple morale and long-term war commitment.

When the United States developed the atomic bomb, they were limited in their options for analyzing its full magnitude. Secluded tests like those at Los Alamos did not go unnoticed by locals, and the longer the weapon was concealed, the more likely it was to have a security breach that may impend the United States from using it when and where they wished to bring about the end of the War. This is seen by the locals who inquired after the first nuclear test at Trinity and were told a fake story about an accident at a munitions depot.

Blowback from Truman's announcement shows that had the United States revealed the Manhattan Project before 1945, it may encountered resistance from the public. The United States fully realized that the Japanese mindset at the time would not consider surrender even if she had no allies in the world -- that a full-scale invasion would be necessary to end WWII.

But if this mindset could be broken by a weapon unlike anything ever seen, the traditional thoughts concerning fighting to the death may be changed, and many lives on both sides could be spared.

And yet the U.S. still had limited information on exactly how big of an explosion Little Boy was capable of. This is the reason for the selection of Hiroshima and, later, Nagasaki. These two cities, as stated in the above answer, had been relatively untouched by the ravages of war, but they also had a concentration of military supplies and troops that would serve as a strategic target. The shape of Hiroshima was geometrically ideal for deploying the bomb as well because from the air, damage could be easily assessed.

The aftermath of the two major bombings supplied researchers with accurate effects of using such weapons, and these ghoulish results were then used to refine and build better weapons that could be used in future situations.

But aside from science, the bombing of Hiroshima was a blow to the Imperial Japanese morale which was not easily bent. After Japan saw not only that we were willing to fight with nuclear technology but that we also had more weapons to use (as was the purpose of the second bombing,) it became clear that WWII was not a engagement that Japan was able to continue at that time. At this point the reality of the situation was literally "surrender or genocide," and no nationalism could replace basic want to survive.

In short, Hiroshima showed the true nature of the Atomic weapon to the world, including both combatants in the Pacific.

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  • @GeorgeASolodun I do not know why this was the selected answer - as it is not the reason for Hiroshima or Nagasaki being selected. Hiroshima had some important points and one of those factors it was not Kyoto which was the first choice but stimson had honeymooned there and said No. 2nd Hiroshima had military value as an assembly and demarcation point of military personnel. 3rd it had significant military industry. Measuring the effects, it was one of the cities that was not bombed by the U.S. in order to determine the destructive capabilities of the weapon. Kokuro was the secondary target.
    – Ken
    Commented Apr 22, 2018 at 5:43
  • @georgeASolodun further you can see from the minutes of the targeting committee in the US National Archives here is a quick web excerpt dannen.com/decision/targets.html
    – Ken
    Commented Apr 22, 2018 at 5:44
  • The argument that the Japanese would have fought to the bitter end is pretty weak. At the time members of the government were already pushing for surrender and many in the military knew that the situation was hopeless. There were back-channel discussions with the US for surrender that could be politically acceptable in Japan on-going when the bombs were dropped.
    – user
    Commented May 9, 2019 at 10:38
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The choice of targets was driven by a few considerations:

  1. The target had to be of strategic importance: things like naval yards, large industrial works, army depots, and similar large facilities. The goal here was to use the new weapon in a way that would inflict significant damage on Japan's warfighting capabilities regardless of any psychological effects. Contrast with Germany's use of the V-2, which had essentially no impact on the Allied military.

  2. The target had to be in an urban area at least three miles across. Nobody really knew what sort of effect a nuclear weapon would have, so by targeting a large city, they would be able to analyze the damage to a range of target types, while at the same time being able to measure the area of effect.

  3. The target had to be somewhere that wouldn't be attacked by August 1945. This ties in with the above criteria, making measurement of damage easier. It also meant the target couldn't be somewhere too important.

  4. The target area had to be highly visible, with psychological value. There's no point in using a new, highly-devastating weapon if the military can cover up the damage done (see: the suppression of news about the loss at Midway).

Certain targets were ruled out for various reasons. The Emperor's Palace in Tokyo was ruled out for having essentially no strategic value (despite having high psychological value). Kyoto was ruled out at the request of the Secretary of War, Henry L. Stimson.

This produced a final list of five targets: Kokura, Hiroshima, Yokohama, Niigata, and Nagasaki (as a substitute for Kyoto). The final choice of Hiroshima was for entirely mundane reasons: on August 6, it was expected to have the best weather of the five targets.

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    If you look at the minutes of the second meeting of the Target Committee, you will find that the "strategic importance" took second place to the points you numbered 2 through 4. They wanted good test results much more than strategic impact (actually preserving the target until the atomic bomb was dropped, i.e. keeping it intact so they could better determine the destructive power of the weapon). The strategic value of the target was a mere afterthought, an "excuse" for the real-life test, if you will.
    – DevSolar
    Commented Jan 17, 2017 at 10:34
  • @DevSolar glad you pointed that out. People just writing their own thoughts gets in the way of historical FACT (oops Historical Facts that is alternate facts in today's world..)
    – Ken
    Commented Apr 22, 2018 at 5:47
  • Actually psychological impact was the important part of the decision - why Kyoto was selected to be first because the scientific minds lived and worked there. They felt it would make the most impact. This also portends to how ignorant they were regarding the destructive power that these weapons really had. You see they thought these intelligent people would still be around after the detonation to argue for surrender.
    – Ken
    Commented Apr 22, 2018 at 5:50
  • Even if news of this weapon got out into the public domain - what data would they have as to its destruction - even looking at Hiroshima they wanted to hit a 2000 x 4000 building. Anyone who was fighting in the war would have said drop it and be done with the war, those that were in the death march (my dads friend was in that), and those that fought in battles of the home islands as well. The fact Japan had chemical weapons being manufactured in Kokuro ( known by the U.S. in the early summer of 1945) most certainly did not hinder the decision to drop it.
    – Ken
    Commented Apr 22, 2018 at 5:56
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One reason is that Hiroshima was one of the few cities in Japan not already bombed by conventional bombing.

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    thats not a very long answer
    – user22718
    Commented Jan 16, 2017 at 23:00
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    @alf-great thats not a very long comment
    – sMaN
    Commented Jan 17, 2017 at 1:48
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    So most every other city in Japan was bombed conventionally? do you have a source for that? Even still, why Hiroshima and not another city (except of course Nagasaki)? Looking at the list of Japanese prefectures and populations in 1944, all of their cities were bombed and so they were outright not considered? I know Japan was hit hard, but I haven't heard that Japan was bombed so thoroughly and it was simply "Hiroshima wasn't conventionally bombed, so let's drop a Nuke instead"
    – BruceWayne
    Commented Jan 17, 2017 at 3:50
  • @BruceWayne: What they wanted was a real-life test of the weapon. An idea on what a nuke would do to a city not already heavily damaged. Those were the actual criteria for target selection: "(1) they be important targets in a large urban area of more than three miles in diameter, (2) they be capable of being damaged effectively by a blast, and (3) they are unlikely to be attacked by next August"
    – DevSolar
    Commented Jan 17, 2017 at 10:38
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    Hiroshima was not already bombed because it had already been selected as a suitable atomic bomb location. In consequence it was deliberately omitted from bombing runs. Commented Aug 4, 2017 at 22:41
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Hiroshima was also a major/important navel bay. The Japanese fleet that fought in the Battle of Midway actually set sail from there. So it was an actual military target. Nagasaki,the site of the second atomic bomb drop,was a major manufacturing center for the Japanese military machine. But you have to remember that Japan vowed to never surrender and fight to the death. So in order to defeat them the Allies had to totally crush them in a way to either destroy them quickly with less Allied life loss or to make them see fighting was hopeless. The atomic bombs did both of that.

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  • Kokuro was the better target - large military industrial complex, chemical weapons manufacturing plants. Large city, and populations however it was covered in clouds and skipped. Nagasaki they missed the drop zone by a significant amount; my guess from reading the log notes is that they never saw the drop zone but said lets get rid of it while we are over the city, the target point was missed by more than 2 miles which is significant! Given the issues they had in getting there - the pressure seemed to be on them to drop the thing.
    – Ken
    Commented Apr 22, 2018 at 6:34

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