In other words, even if it had lost catastrophically at the Battle of Midway, the United States Navy still would have broken even with Japan in carriers and naval air power by about September 1943. Nine months later, by the middle of 1944, the U.S. Navy would have enjoyed a nearly two-to-one superiority in carrier aircraft capacity! Not only that, but with her newer, better aircraft designs, the U.S. Navy would have enjoyed not only a substantial numeric, but also a critical qualitative advantage as well, starting in late 1943. All this is not to say that losing the Battle of Midway would not have been a serious blow to American fortunes! For instance, the war would almost certainly have been protracted if the U.S. had been unable to mount some sort of a credible counter-stroke in the Solomons during the latter half of 1942. Without carrier-based air power of some sort there would not have been much hope of doing so, meaning that we would most likely have lost the Solomons. However, the long-term implications are clear: the United States could afford to make good losses that the Japanese simply could not. Furthermore, this comparison does not reflect the fact that the United States actually slowed down its carrier building program in late 1944, as it became increasingly evident that there was less need for them. Had the U.S. lost at Midway, it seems likely that those additional carriers (3 Midway-class and 6 more Essex-Class CVs, plus the Saipan-class CVLs) would have been brought on line more quickly. In a macro-economic sense, then, the Battle of Midway was really a non-event. There was no need for the U.S. to seek a single, decisive battle which would 'Doom Japan' -- Japan was doomed by its very decision to make war.There's tons of production data at that link, a lot of which I hadn't known. For example, we built 11 Million tons of merchant shipping just in 1943. We built nearly 100,000 aircraft just in 1944. Ye gods. (via)
Also, the Atomic Bomb didn't end the war. The entry of the Soviet Union into the Pacific Theater did:
In the three weeks prior to Hiroshima, 26 cities were attacked by the U.S. Army Air Force. Of these, eight — or almost a third — were as completely or more completely destroyed than Hiroshima (in terms of the percentage of the city destroyed). The fact that Japan had 68 cities destroyed in the summer of 1945 poses a serious challenge for people who want to make the bombing of Hiroshima the cause of Japan’s surrender. The question is: If they surrendered because a city was destroyed, why didn’t they surrender when those other 66 cities were destroyed?What's particularly interesting is the conclusion (you'll have to click through to RTWT), but it's very Japanese. Much face was saved, and not just in Japan.
One way to gauge whether it was the bombing of Hiroshima or the invasion and declaration of war by the Soviet Union that caused Japan’s surrender is to compare the way in which these two events affected the strategic situation. After Hiroshima was bombed on August 8, both options were still alive. It would still have been possible to ask Stalin to mediate (and Takagi’s diary entries from August 8 show that at least some of Japan’s leaders were still thinking about the effort to get Stalin involved). It would also still have been possible to try to fight one last decisive battle and inflict heavy casualties. The destruction of Hiroshima had done nothing to reduce the preparedness of the troops dug in on the beaches of Japan’s home islands. There was now one fewer city behind them, but they were still dug in, they still had ammunition, and their military strength had not been diminished in any important way. Bombing Hiroshima did not foreclose either of Japan’s strategic options.
The impact of the Soviet declaration of war and invasion of Manchuria and Sakhalin Island was quite different, however. Once the Soviet Union had declared war, Stalin could no longer act as a mediator — he was now a belligerent. So the diplomatic option was wiped out by the Soviet move. The effect on the military situation was equally dramatic. Most of Japan’s best troops had been shifted to the southern part of the home islands. Japan’s military had correctly guessed that the likely first target of an American invasion would be the southernmost island of Kyushu. The once proud Kwangtung army in Manchuria, for example, was a shell of its former self because its best units had been shifted away to defend Japan itself. When the Russians invaded Manchuria, they sliced through what had once been an elite army and many Russian units only stopped when they ran out of gas.