Demographics are collapsing in much of Europe, in particular Eastern Europe and in West Taiwan, Japan, KPop Korea and Taiwan.
Also to quote Iron Man to Loki, not a good plan.
As Russia was under no threat from it's neighbors the war was not a must to win.
I know there is this one commentator on the youtube who goes on about Russia, demographics and how it must control the routes of entry, but he is obsessed with his hobby horse and it blinds him to everything else. He also has a record of making nearer term predictions and removing videos when they inevitably don't come true.