The question of “Was the US dropping the atomic bombs on Japan justifiable?” is a question that we have all heard at some point. I hear both sides of the argument. What I want to know is what is the truth behind Japan’s decision to surrender. Were they truly on the verge of surrendering before the US dropped the atomic bombs or because of their culture they had no intentions on surrendering, so dropping the bombs was necessary to save both Japanese and American lives. I just want to know the truth. Also, how many bombs did the US have planned? I read somewhere that the US had a third bomb ready and more in development. Is that true?
"Was Japan on the verge of surrendering in early August 1945" : this is a question that cannot be definitively answered, but the current consensus is "no, they weren't".
Certainly the Japanese high command realized that they had lost the war. However, they still believed that some sort of negotiated peace was possible short of unconditional surrender. They were thinking in terms of territorial concessions, withdrawing from China, and the like, in return for peace -- but with Japan avoiding occupation and maintaining continuity of government and an independent foreign policy. The were certainly not ready to accept Allied (American) occupation of Japan. Beginning in June, they had been sending out tentative peace feelers -- but these were invitations to negotiate, not preludes to surrender.
The Japanese leadership was well aware that an invasion of the Japanese mainland would be very bloody for the Allies. They had a pretty good idea of where and when the Americans were coming (they thought it would happen in southern Kyushu in October; it was actually planned for southern Kyushu in November) and were aggressively preparing defenses. The defense of Okinawa had been very encouraging in this regard -- it had cost the Americans around 70,000 casualties along with several warships. The Japanese didn't know that exact number, of course, but they realized that the Americans had been made to bleed.
There's debate about what exactly the Japanese leadership thought they could obtain, but they seem to have been thinking in terms of the end of World War One: something like a Treaty of Versailles, with Japan giving up territory and possibly accepting limits on armed forces. After all, in 1918, the Allies had the military capacity to march into Germany and occupy it, but public war-weariness and the immense cost of continuing the war caused them to accept an armistice and a limited victory instead of complete surrender and occupation. The Japanese reasoning seems to have been, we can rope-a-dope and rack up Allied casualties until cost and war-weariness force the Allies to accept something similar.
A point that often gets overlooked is that while Japan had clearly lost the war by summer 1945, they were not beaten in the way that Germany had been beaten. By April 1945 most of Germany had already been conquered and occupied by Allied troops, including the key centers of industry and commerce, and the German army was collapsing. The Japanese perception was that Germany had fought and lost their climactic battle -- but that Japan had not yet. So, why surrender before you had actually been beaten?
This isn't really a "because of their culture" thing, btw. There are plenty of historical examples of adroit diplomacy, surprise military victories, or just plain luck causing a sudden shift in fortunes and snatching victory, or at least reduced defeat, at the last minute. So, why not dig in, hope, and roll the dice one more time? This was a desperate strategy, and brutally callous to civilian casualties -- but it wasn't obviously insane. Japan fighting on in the summer of 1945 was arguably no more "crazy" than (for instance) the Confederate States of America continuing to fight on in the spring of 1865.
Insofar as there is a consensus among historians, it is probably that the atomic bombs plus the Soviet declaration of war were a horrifying one-two-three punch that dramatically changed Japan's outlook. The Soviet DOW does not always get the attention it should, but it was a huge shock to Japan's leadership. They had grown very complacent about the USSR, perceiving Stalin as a friendly neutral who would help them negotiate with the other Allies. So Moscow's sudden heel-turn came as a huge shock -- especially since it was accompanied by a massive invasion that had obviously been months in preparation.
These are excellent insights. I apologize if this is too far off topic; did the firebombing of Tokyo play any significant part in showing the Japanese leadership that they were going to lose?
In regards to the bomb
Archival records show a third bomb was under assembly at Tinian in the Mariana Islands where the Enola Gay and Bockscar had flown from, with the main plutonium core about to be shipped from the U.S.
Although some aircrew saw “Tokyo Joe” chalked on the bomb’s casing, it was said to be destined for Kokura, the original target for the second bomb, and named “Fat Boy.”
A transcript of a top-level call between two military experts on August 13 reveals details of this “third shot.” It also confirmed that a vast production line of about 12 other atomic bombs was being readied for additional continuous strikes against other key targets.
It was agreed this next bomb would be available to be dropped on August 19, with a schedule of further bombs available throughout September and October.
One U.S. general explained: “If we had another one ready, today would be a good day to drop it. We don’t, but anyhow within the next ten days, the Japanese will make up their minds.”
On August 15, however, just as the plutonium was about to be sent to Tinian, news of the Japanese surrender came through and its loading was stopped.
Don Hale - Daily Beast article US planned to drop 12 atomic bombs on Japan.
Info from According to information from London-American military archives. Will find a footnote