They. can't. do. that. They physicly don't have the capability of pulling that off. Like you said their low on artilery and the army and citizenry already hate the admin. America is already under pressure trying to fight Iran, it can't start a bunch of wars for resorces it doesn't have. it's military isn't built for it anymore and a lot of the capable military minds have left or were kicked out.

Putin won't get ukraine but at least he gets to watch his life long rival, America, eat absolute shit before he crokes.