Today, December 7, is the day that would live in infamy. The day of the Pearl Harbor attack. One of the greatest blunders in history. In exchange for the total loss of only two older battleships, the IJN solved the final piece of the puzzle for the US’s long-studied and long-gamed out war plan-how to maintain public opinion for a long war while the buildup progressed (answer-by providing such a dramatic “shot heard ’round the world”) and how to avoid a rushed politically-driven offensive that could give their opponents the 1905-esque “decisive battle” they were looking for (answer-by disabling the battleline juuuust long enough to make that impossible before the Philippines fell).
From there, it was all over. I could argue that the tide turning in the Pacific wasn’t Midway or even Guadalcanal. It was when the first Essex-class carrier entered service. And there’d be a lot more where that came from. A whole lot more.