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It would depend on the scenario. I suggest you just write, let the changes to history that you make lead you and the reader to interesting places. The movie Fatherland has an interesting scenario ...
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Source: https://writers.stackexchange.com/a/42187 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#2: Initial revision
It would depend on the scenario. I suggest you just write, let the changes to history that you make lead you and the reader to interesting places. The movie Fatherland has an interesting scenario where World War II never happened and JFK was not assassinated. This led to a world with a thriving Germany ruled by the Nazi party and Hitler, the US President was none other than an older JFK. Let your dominoes fall or not. Start writing and see where it leads. The ‘what if x never happened’ can be a compelling question to explore. Consequences radiate outward and the changes caused by one alteration can be considerable and far reaching. Sounds like fun. If the era is far enough back in time that most readers might not be immediately aware of its history, you might want to research first.