But most of the top American military officials at the time said otherwise.
The U.S. Strategic Bombing Survey group, assigned by President Truman to study the air attacks on Japan, produced a report in July of 1946 that concluded (52-56):
Based on a detailed investigation of all the facts and supported by the testimony of the surviving Japanese leaders involved, it is the Survey’s opinion that certainly prior to 31 December 1945 and in all probability prior to 1 November 1945, 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.
General (and later president) Dwight Eisenhower – then Supreme Commander of all Allied Forces, and the officer who created most of America’s WWII military plans for Europe and Japan – said:
The Japanese were ready to surrender and it wasn’t necessary to hit them with that awful thing.
Newsweek, 11/11/63, Ike on Ike
Eisenhower also noted (pg. 380):
In [July] 1945… Secretary of War Stimson, visiting my headquarters in Germany, informed me that our government was preparing to drop an atomic bomb on Japan. I was one of those who felt that there were a number of cogent reasons to question the wisdom of such an act. …the Secretary, upon giving me the news of the successful bomb test in New Mexico, and of the plan for using it, asked for my reaction, apparently expecting a vigorous assent.
During his recitation of the relevant facts, I had been conscious of a feeling of depression and so I voiced to him my grave misgivings, first on the basis of my belief that Japan was already defeated and that dropping the bomb was completely unnecessary, and secondly because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment was, I thought, no longer mandatory as a measure to save American lives. It was my belief that Japan was, at that very moment, seeking some way to surrender with a minimum loss of ‘face’. The Secretary was deeply perturbed by my attitude….
Admiral William Leahy – the highest ranking member of the U.S. military from 1942 until retiring in 1949, who was the first de facto Chairman of the Joint Chiefs of Staff, and who was at the center of all major American military decisions in World War II – wrote (pg. 441):
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.
General Douglas MacArthur agreed (pg. 65, 70-71):
MacArthur’s views about the decision to drop the atomic bomb on Hiroshima and Nagasaki were starkly different from what the general public supposed …. When I asked General MacArthur about the decision to drop the bomb, I was surprised to learn he had not even been consulted. What, I asked, would his advice have been? He replied that he saw no military justification for the dropping of the bomb. The war might have ended weeks earlier, he said, if the United States had agreed, as it later did anyway, to the retention of the institution of the emperor.
Moreover (pg. 512):
The Potsdam declaration in July, demand[ed] that Japan surrender unconditionally or face ‘prompt and utter destruction.’ MacArthur was appalled. He knew that the Japanese would never renounce their emperor, and that without him an orderly transition to peace would be impossible anyhow, because his people would never submit to Allied occupation unless he ordered it. Ironically, when the surrender did come, it was conditional, and the condition was a continuation of the imperial reign. Had the General’s advice been followed, the resort to atomic weapons at Hiroshima and Nagasaki might have been unnecessary.
Similarly, Assistant Secretary of War John McLoy noted (pg. 500):
I have always felt that if, in our ultimatum to the Japanese government issued from Potsdam [in July 1945], we had referred to the retention of the emperor as a constitutional monarch and had made some reference to the reasonable accessibility of raw materials to the future Japanese government, it would have been accepted. Indeed, I believe that even in the form it was delivered, there was some disposition on the part of the Japanese to give it favorable consideration. When the war was over I arrived at this conclusion after talking with a number of Japanese officials who had been closely associated with the decision of the then Japanese government, to reject the ultimatum, as it was presented. I believe we missed the opportunity of effecting a Japanese surrender, completely satisfactory to us, without the necessity of dropping the bombs.
Under Secretary of the Navy Ralph Bird said:
I think that the Japanese were ready for peace, and they already had approached the Russians and, I think, the Swiss. And that suggestion of [giving] a warning [of the atomic bomb] was a face-saving proposition for them, and one that they could have readily accepted.
In my opinion, the Japanese war was really won before we ever used the atom bomb. Thus, it wouldn’t have been necessary for us to disclose our nuclear position and stimulate the Russians to develop the same thing much more rapidly than they would have if we had not dropped the bomb.
War Was Really Won Before We Used A-Bomb, U.S. News and World Report, 8/15/60, pg. 73-75.
He also noted (pg. 144-145, 324):
It definitely seemed to me that the Japanese were becoming weaker and weaker. They were surrounded by the Navy. They couldn’t get any imports and they couldn’t export anything. Naturally, as time went on and the war developed in our favor it was quite logical to hope and expect that with the proper kind of a warning the Japanese would then be in a position to make peace, which would have made it unnecessary for us to drop the bomb and have had to bring Russia in.
General Curtis LeMay, the tough cigar-smoking Army Air Force “hawk,” stated publicly shortly before the nuclear bombs were dropped on Japan:
The war would have been over in two weeks. . . . The atomic bomb had nothing to do with the end of the war at all.
The Vice Chairman of the U.S. Bombing Survey Paul Nitze wrote (pg. 36-37, 44-45):
[I] concluded that even without the atomic bomb, Japan was likely to surrender in a matter of months. My own view was that Japan would capitulate by November 1945.
Even without the attacks on Hiroshima and Nagasaki, it seemed highly unlikely, given what we found to have been the mood of the Japanese government, that a U.S. invasion of the islands [scheduled for November 1, 1945] would have been necessary.
Deputy Director of the Office of Naval Intelligence Ellis Zacharias wrote:
Just when the Japanese were ready to capitulate, we went ahead and introduced to the world the most devastating weapon it had ever seen and, in effect, gave the go-ahead to Russia to swarm over Eastern Asia.
Washington decided that Japan had been given its chance and now it was time to use the A-bomb.
I submit that it was the wrong decision. It was wrong on strategic grounds. And it was wrong on humanitarian grounds.
Ellis Zacharias, How We Bungled the Japanese Surrender, Look, 6/6/50, pg. 19-21.
Brigadier General Carter Clarke – the military intelligence officer in charge of preparing summaries of intercepted Japanese cables for President Truman and his advisors – said (pg. 359):
When we didn’t need to do it, and we knew we didn’t need to do it, and they knew that we knew we didn’t need to do it, we used them as an experiment for two atomic bombs.
Many other high-level military officers concurred. For example:
The commander in chief of the U.S. Fleet and Chief of Naval Operations, Ernest J. King, stated that the naval blockade and prior bombing of Japan in March of 1945, had rendered the Japanese helpless and that the use of the atomic bomb was both unnecessary and immoral. Also, the opinion of Fleet Admiral Chester W. Nimitz was reported to have said in a press conference on September 22, 1945, that “The Admiral took the opportunity of adding his voice to those insisting that Japan had been defeated before the atomic bombing and Russia’s entry into the war.” In a subsequent speech at the Washington Monument on October 5, 1945, Admiral Nimitz stated “The Japanese had, in fact, already sued for peace before the atomic age was announced to the world with the destruction of Hiroshima and before the Russian entry into the war.” It was learned also that on or about July 20, 1945, General Eisenhower had urged Truman, in a personal visit, not to use the atomic bomb. Eisenhower’s assessment was “It wasn’t necessary to hit them with that awful thing . . . to use the atomic bomb, to kill and terrorize civilians, without even attempting [negotiations], was a double crime.” Eisenhower also stated that it wasn’t necessary for Truman to “succumb” to [the tiny handful of people putting pressure on the president to drop atom bombs on Japan.]
British officers were of the same mind. For example, General Sir Hastings Ismay, Chief of Staff to the British Minister of Defence, said to Prime Minister Churchill that “when Russia came into the war against Japan, the Japanese would probably wish to get out on almost any terms short of the dethronement of the Emperor.”
On hearing that the atomic test was successful, Ismay’s private reaction was one of “revulsion.”
Why Were Bombs Dropped on Populated Cities Without Military Value?
Even military officers who favored use of nuclear weapons mainly favored using them on unpopulated areas or Japanese military targets … not cities
For example, Special Assistant to the Secretary of the Navy Lewis Strauss proposed to Secretary of the Navy James Forrestal that a non-lethal demonstration of atomic weapons would be enough to convince the Japanese to surrender … and the Navy Secretary agreed (pg. 145, 325):
I proposed to Secretary Forrestal that the weapon should be demonstrated before it was used. Primarily it was because it was clear to a number of people, myself among them, that the war was very nearly over. The Japanese were nearly ready to capitulate… My proposal to the Secretary was that the weapon should be demonstrated over some area accessible to Japanese observers and where its effects would be dramatic. I remember suggesting that a satisfactory place for such a demonstration would be a large forest of cryptomeria trees not far from Tokyo. The cryptomeria tree is the Japanese version of our redwood… I anticipated that a bomb detonated at a suitable height above such a forest… would lay the trees out in windrows from the center of the explosion in all directions as though they were matchsticks, and, of course, set them afire in the center. It seemed to me that a demonstration of this sort would prove to the Japanese that we could destroy any of their cities at will… Secretary Forrestal agreed wholeheartedly with the recommendation…
It seemed to me that such a weapon was not necessary to bring the war to a successful conclusion, that once used it would find its way into the armaments of the world…