The entire west looks pretty shaky economically, socially, demographically, in general. I could understand Russia/China/Iran wanting to wait and let it collapse on its own.

On the other hand, Russia can't claim this red line and that red line but never do anything when they are crossed. At some point you have to actually do something or lose credibility.

My best guess is Russia is trying to slow the escalation down as much as possible, hoping the west collapses on its own before things get too serious. The problem is that the political response to internal collapse could be the west starting an external war. They seem to be quite keen on that.