I don't foresee world nations and humankind engaging in a world war akin to the "old days".
I mean in the war style seen during WW2. There'll always be some kinda war, but short duration, and numerous battles and skirmishes will take place as always.
As for this Russia vs USA scenario, I see it as just brainwashing.
Both sides are playing in concert with each other, scripted, so to speak. We aren't enemies - witness the International Space Station.
Who are the 2 parties working together ? Why isn't it Russia and China and NoKo? Or Germany and US?
Or Japanese and US?
No, it's the US of A and Russia. To partner up in the heavens only to squabble and fight on the earth... does it make sense to U?
Common sense would say "No".