"It is my opinion 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 because of the effective sea blockade and the successful bombing with conventional weapons.
"The lethal possibilities of atomic warfare in the future are frightening. 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 not taught to make war in that fashion, and wars cannot be won by destroying women and children."
ADMIRAL WILLIAM D. LEAHY
(Chief of Staff to Presidents Franklin Roosevelt and Harry Truman)
His opinion is just that an OPINION. And it is not backed up with the FACTS. Even after one atomic bomb was dropped the ruling Council REFUSED to surrender and demanded basically a ceasefire with a return to Nov 1941 start lines. No troops in Japan and no lose of Chinese or Korean captured territory.
Even after months of none stop bombing, almost no shipping, winter coming and no way to feed the people or heat their homes the Japanese Army REFUSED to surrender and had no intention of surrendering. It even began cutting bamboo to provide spears to the civilians to human wave attack the landing sites. It had convinced the population that its enemies were monsters and that they should kill themselves rather then surrender. Saipan, Okinawa all provided adequate proof that the Civilians believed the Government.