There is no doubt that the rest of the world benefitted greatly from the defeat of Hitler at the end of WWII. However, the defeat of Germany as a whole led to the marginalisation of some schools of thought originating in Germany and Austria, which have had lasting consequences and are still only being slowly corrected today.
Mathematics: Bertrand Russell vs. Kurt Gödel
The first, and maybe the most important, is the area of mathematics. Here Bertrand Russell the esteemed British mathematician is famous for having “proved” mathematics. QI even repeat this myth in one of their shows. However, his Austraian counterpart Kurt Gödel in his incompleteness theorem, arguably demonstrated that Mathematics cannot be proved. Specifically, that a set of Mathematical rules cannot be shown to be consistent and complete at the same time. The implications of this are that the rules of mathematics are not provable, but a set of a priori assumptions that you have to accept are true and find that they work in practice.
Within epistemology, this means that we cannot be certain of anything and that trusting something, having faith in something, proceeds knowledge. This flips our current modern world view on its head, meaning that sciences being equated with facts is broken down. It is not that we don’t still trust scientific knowledge, only that it cannot claim certainty or automatically trump other sources of knowledge. This actually fits with many recent developments within science itself, where areas such as complexity theory, quantum physics and emergent systems, often deal much more in probabilities than absolutes.
Diet: Fat vs. Carbohyrate
In the area of diet, German dieticians had been studying carbohydrates as the primary driver in type 2 diabetes. However, Ancel Keys and his vegetarian and low-fat beliefs shaped nutritional guidelines for half a century. Thankfully that is finally starting to change and we are now seeing consensus coming around to the true viewpoint.
Connecting it with mathematics, this is an example of how science isn’t always certain, and that incorrect beliefs, particularly in complex systems like the human body, can persist for a considerable amount of time before being corrected.
Economis: Keynesianism vs. Austrian
Finally in economics, as the allied powers lead the emerging global world order, John Maynard Keynes won out over Ludwig von Mises and Austrian economics, leading to large amounts of malinvestment, environmental destruction, unsustainable debt levels and massive wealth inequality.