But imagine how different things would have been if the fight between Germany/Austria-Hungary and Russia would have been localized in 1914. ==
It would be impossible. Because Germany had more interests on west of her than on east. And they knew the lesson of Napoleon. You may even get to Moscow BUT it will NOT help you to win. It was proved again in 1941.
And you must bring all your troops there and it will not be enough.
SO when Germany and Austria inevitably stick in a vast forests of Russia they would be attacked into their backs by same France and UK. And they would have a war on 2 fronts which they lose.
SO Germany and Austria realized and never wanted this.
Germany attacked in 1914, because she knew Russia was modernizing rapidly, and it was a classic case of “now or never”, they estimated that in five years it would be impossible to defeat Russia.
As I saw some Freeper say here, “If diversity is our strength, then Austria-Hungary would have won WWI”