This is bluster. The Russians aren’t going to push east as they’d encounter too much resistance, also, they’ve got Europoe already under their thumb for an energy viewpoint. South is now the path of least resistance, possibly through Armenia or Azerbaijan into Iran. That has a greater potential of economic disruption with less cost. Russia cannot take the west on militarily, but by further consolidation of oil and gas reserves they can slowly squeeze the west and Europe in particular.
Putin is furious, he may allow his emotions now to get the better of hom and overplay his hand. But I do believe now south is the direction they move.
Excuse me, I meant push west not east.