33

A single car accident could do the trick Emperor Hirohito had a younger brother named Takamatsu. In 1930-1931, Takamatsu chose to travel across the US and Europe to improve relations with Western Civilization and became much more fond of and respectful of Western nations than his brother. He was fairly successful at this and garnered a lot of respect ...


25

Put Guderian in charge of the invasion of France and let him handle things. Don't interfere or tell him to halt the advance under any circumstances. If the UK offers a negotiated surrender, take it. Also, don't attack Russia. If you absolutely cannot resist attacking Russia, then be patient; don't do it until after France and the UK are defeated. Again, don'...


19

I think that if you made two changes to history, that it would be believable that the USA and Japan became allies. The first change is to alter the Meiji Restoration to be more defensively focused and less conquest motivated. If the outcome of the Meiji Restoration was to make Japan a leader in the fields of modern technology and comfortably able to defend ...


13

Don't fight a war on two fronts. The obvious answer is that the German resources were stretched by attacking Russia while it was pushing into France. On top of it all, they attacked at a point when all the Russians had to do was keep them outdoors during a Russian winter and let many of the enemy soldiers die. Is it possible Russia would have attacked ...


13

Your Enigma isn't as secure as you think. (Followed by: let me explain public key cryptography to you). The allied forces had a significant advantage through code-breaking while the Germans considered it unbreakable. Whether you know or are unaware of the coming ATTACK AT DAWN, this may eventually turn things around. It's your story that makes this work :-)...


11

No information would help Nazi Germans to win the war - only to avoid it, like fascist Spain did. My first argument - Nazis are Nazi, you can't make them "softer", and they did the best they could Long term war was not a German choice. They planned to end the war with Russia at the end of summer of 1941 (and they almost did it!) and to conquer all "living ...


10

As the top answer in the linked question indicates, this sort of mutation is a very serious problem for humanity which fortunately can be quite easily mitigated with modern national- and international-level identification and amelioration programs. So it is essential that your story begins prior to the discovery of modern genetics at the beginning of the ...


9

Yes they could, in fact some ancient civilizations are believed to have experimented with the use of moulds to help cure wounds. The problem being they were not aware of what was going on so their methods might be best described as haphazard. Someone who knew (by some means) of the existence of and presumably the effect of penicillin might well be able to ...


9

It can't be done. To understand why you have to know the actual history. Fleming accidentally discovered a contaminating mould killed off his bacterial cultures in Petri dishes. Did this give the world Penicillin? No, not at all. No-one knew how to produce or culture on any scale. Come the Second World war and it became imperative to keep wounded soldiers ...


8

The Republic of China defeats the Communist Party of China The PRC, and specifically Chairman Mao, are responsible for the Great Leap Forward and the Cultural Revolution. These two events inflicted grave damage to China culturally, scientifically, and economically. Neither would have happened had the Chinese Civil War ended differently. So change the ...


8

According to wikipedia, relations began to sour when Japan attacked the USS Panay and committed the Nanjing Massacre during the Second Sino-Japanese War. These two events drastically altered foreign sentiment, and painted Japan as the clear bad-actor in the war. This led to arms sales to China, and Oil Embargoes, which is largely believed to be the straw ...


8

Make Mao Zedong and the Chinese communists much, much more successful in the 1930's. A united communist China, especially one powerful enough to export revolution, would be seen as a threat to US commercial interests in Asia. The US would then favor and support Japan's invasion of China.


7

Mathematics development has been strongly bond to practical necessities until very recent times. You need to count your sheep or carrots? Here you are your integers. You need to measure your fields after each flood? Here is your trigonometry. You need to count your money deposit? Here you are your relative numbers. And so on and so forth, until modular ...


6

The most obvious alternative history difference with these two types of lignin-reduced woods would be: It would replace fiberglass. Especially the "nanowood" as insulation, and as a resin-filled shock resistant building material. Since wood can not be poured, extruded, moulded, drawn, blown, welded, or cast, it would have a disadvantage to materials that ...


6

There would be no world war, very obviously. It would be just one of the many little wars in the Balkans. Bye-bye Servia (as it was known in the west at that time). But the premise is not believable: Germany was waiting with bated breath for a reason, any reason, to go to war against France. They were counting down the days until the developing French power ...


6

Modern "gunpowder" isn't really a powder, it's only people call it that because it replaced black powder. Honestly, as long as you can make black powder, you can also make it, all you need is know-how. All you have to do is convert sulfur into sulfuric acid, saltpeter into nitric acid, and instead of charcoal, get cellulose. Usually, cellulose used for this ...


5

Conceptually, batteries have been around for a very long time, some of the earliest forms that we would recognise coming into existence around 1749 but that would certainly not be a battery in the kilowatt storage range, and that is unlikely to be developed because electrical storage was not the limiting factor; it was electrical generation. In 1861, the ...


5

What made Rome what it was? Luck and Momentum Take a bunch of farmer and herder villages. One bunch of barely-organized militia conquers another. Then another. Perhaps it could have been the other way around. What was it why Rome came up on top and not Capua or Tarentum? A tiny initial advantage or pure luck? Wise Laws Was Rome better organized than their ...


5

The most obvious difference between OTL and the "woodpunk" world would be the importance of forestry and the handling of forests. In the 19th and early 20th century, forestry was more akin to strip mining, with enormous lots clearcut and then left to regrow on their own, often with little or no attention paid to the process by the loggers. This was somewhat ...


5

Yes Fences can keep out megafauna but the key to doing it successfully is plenty of space and not many humans. If you look at Africa, farmers use beehives and thorn bushes to protect crops from elephants See Comparing the effectiveness of beehive fences to thorn barriers in farm invasions and exits by elephants The real problem is too many people ...


5

The seeds would have to be planted in the 1918 intervention against the nascient Soviet Union, when American troops were in Siberia to support the "White" Russians, and Japan and the British Empire were still allies. Since the US, the British Empire and Japan all have reasons to be allied against the Soviet Union, then the expansion of Soviet power needs to ...


4

Just hand them the history book They don't need technical information, access to the 20/20 hindsight that we have available would be enough to change everything, and if they don't take that hint there's no helping them. There were many mistakes made by all sides in the run up to, and during the war. Given access to that information, advance knowledge of D-...


4

A reincarnation of the Holy Roman Empire in the 1940's would have an abysmal military strength. Defensively, the armor employed by by the Holy Roman Empire would in no way stand up to automated machine gun fire or artillery or any kind. The Holy Roman Empire would have no way of protecting its troops from a moderately well equipped army. Offensively, ...


4

Since the universe branching only began at the moment of the Trinity explosion, something must have been keeping it from branching up to that moment and that something must have been disabled during the blast. By the most bizarre coincidence, the location of the trinity test just happened to also be the location where the trans-dimensional police installed ...


4

As you mention the space race is a very important part of the technological advancement. During the time of NASA's moon projects an absolutely ridiculous amount of money was thrown into technological developments that then were used for technological advancement on the planet itself. If this had been kept up there would have been a much faster technological ...


4

I feel like this question rather belongs in the History StackExchange. That being said, one can still speculate on the most plausible outcome of a refusal on the German Empire's part to back up Austria-Hungary in 1914. First, lets provide some preliminary context : By 1914, almost all European nations were involved in a complex maze of alliances, pacts ...


3

Chairman Mao took a page out of Ataturk's book and moved to change to writing in China to use Latin script, but with phonetic spelling of words. Ataturk changed Turkey's writing to use mostly Latin script (they have 2 different I's and some letters come with bonus accents) instead of Arabic characters This could make it easier to teach reading and writing ...


3

Not really "before WW2 begins" but during the war could reveal things like opponents movements and supplies. If he knew which battles to avoid/write-off, which supply routes were vulnerable, and the advice not to invade Russia could have done a lot to avoid wasting resources and being more effective in dominating. Also, location of various manufacturing ...


3

You would have to assume a rational German leadership that was willing to act on the advice. If there had been such a leadership, wouldn't they have listened to the German advisors who would have argued against two-front wars, declaring war on the United States, and so on? I don't think there are simple one-paragraph pieces of advice that could make Germany ...


3

Without metallurgy you will be vastly limited in what you can do. Stone is strong in compression, but weak under tension. A cannon is essentially a gas pressure chamber that puts the walls under tension so it would not work. Instead may I suggest using it to startle and surprise the enemy. A shallow trench filled with gunpowder placed around the perimeter ...


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