War is a beast with an independent will. Parties enter into war thinking they can manage the outcome. This has never been the case through history.
It may seem like nationalist egocentricity, but I think a lot hinges on the U.S. election. Fear of a Trump win may accelerate the West's willingness to green light Ukraine. If they don't do it now, and Trump wins, game over. I think Putin has always had his eye on this outcome also. With Trump looming as a possible victor, Putin just has to bide his time. With Trump in, support for Ukraine evaporates.
But let me repeat: War is a beast with an independent will. Everybody making a calculation and nobody in control.