If the US Navy hadn't recovered so quickly after Pearl Harbor, and if the Enigma Code hadn't been cracked then we'd all be hailing the Emperor of Japan right now. I mean the first nuclear test wouldn't have been in the middle of a desert, it would have been over mainland China. The USSR would likely have never invaded Japan, keeping their neutrality pact alive would have meant the Japanese would have had free reign to attack anywhere they saw fit.
The whole of WWII is extremely complicated. I mean the reason for the whole delay in the Japanese surrender to the US after the atomic bombings was because they didn't plan to, until the USSR invaded Japanese territory, breaking a neutrality pact and covering almost as much land in days as the US had managed in months. The Japanese were afraid of being conquered by the USSR because of the atrocities they committed against Russians at the start of the war. So Japan didn't surrender to the allies, they surrendered ONLY to the USA so they would have to be protected from the Russians, incidentally because they knew the US had the A-Bomb they knew it would have to be used in their protection if Russia kept invading.
So just the simple 'the A-Bomb won the war' theory is a billion times more complicated than the lay person understands. Hindsight is 20/20, but you're still as blind as the point of view you're looking from. The American POV for the war is very blind of what truly happened during the war compared to the British POV; I'm British and when studying history we were taught that because the US was so late coming into the war it was solely the British Navy and RAF keeping the German Navy from expanding out into the Atlantic. If it wasn't for the British then it wouldn't have been Pearl Harbor, it would have been a full-out invasion by the Germans long before anyone even dreamed of D-Day.