A war between Great Powers# is automatically a NUKE war; so why man borders.
# Great Powers= Nuke powers who have the capacity of hitting anywhere on the planet and at volume within half an hour.
Both Russia & the USA are capable of that.
At the start of this war Russia has issued a warning to NATO (defacto to the US) that it would use Nukes to defend its territory so for Russia to mass Troops on its western Border is an oxymoron because it would deter it from using tactical Nukes initially.
I guess there's a big gap between grade 6 Geopolitics and the more mature perspective....eh?