workingclasshistory:

On this day, 6 August 1945, the US dropped an atomic bomb on Hiroshima, slaughtering tens of thousands of civilians, despite many military and government officials believing it was unnecessary. Numerous senior US military officers confirmed that the bombing was not needed to defeat Japan, and indeed that Japan was attempting to surrender.
General Dwight D. Eisenhower explained: “Japan was at the moment seeking some way to surrender with minimum loss of ‘face’. It wasn’t necessary to hit them with that awful thing.” Admiral William D. Leahy, former chair of the Joint Chiefs of Staff stated “that the use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender. My own feeling was that in being the first to use it, we had adopted an ethical standard common to the barbarians of the Dark Ages. I was taught not to make war in that fashion, and wars cannot be won by destroying women and children.”
And the US Strategic Bombing Survey determined that “Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no invasion had been planned or contemplated.”
Elements within the Japanese government had been attempting to arrange a surrender, while maintaining the institution of the emperor, which possessed important religious significance. The US meanwhile was insisting on an unconditional surrender, but even though this was the only supposed barrier to peace, the US allowed Japan to maintain the emperor after the surrender anyway.
Faced with criticism of the mass-killing of civilians, some US officials concocted a narrative that the bombs were used to avoid a land invasion of Japan which would have cost more lives. However, this story was only fabricated in 1947, after the war had already ended.
More likely was that the US wanted to send a strong message to Russia before the cold war began. https://www.facebook.com/workingclasshistory/photos/a.296224173896073/2051125201739286/?type=3