I think the question is whether they can take Kyiv before there is a domestic backlash to casualties and economic disruptions. Putin clearly wants to take Kyiv before conducting serious negotiations, but it isn't clear Russia can do so fast enough, especially if Kharkiv holds out
I think Moscow underestimated the amount of resistance they would face, the casualties they would sustain, the amount of time this would take, the response from foreign governments and corporations, and how much their soldiers would need to be informed of what they were doing. 2/
The irony is that Russian officials have long (correctly) thought the US was crazy for invading Iraq. And Putin has a fairly successful record in employing military force, but he decided to pursue maximalist political objectives this time based on poor assumptions. 3/
The best thing the US can do to help Ukraine is to convince Putin that de-escalation is a less costly and risky option for him than continuing the war. Calling for regime change or assassination does the opposite.
NATO arms exports are shaping Russia's cost-benefit analysis by making the war more costly. These comments will just become fodder for Russian news to argue that regime change has always been the US' goal, which isn't true.
Russia is sustaining far higher casualties than in any of the previous wars under Putin and the Russian economy is suffering increasingly severe disruptions. That will likely lead to a domestic backlash. The question is whether that will happen before Russia levels Kyiv.
At this point, the costs of the invasion are locked in for Russia. Even if Moscow finds some sort of compromise, government sanctions will remain as will the blacklisting from private corporations. This likely affects Russia's cost-benefit analysis of continuing the war.
Thus far, Russia hasn't achieved any significant political goals but has sustained most of the costs, so it has an incentive to continue the conflict. I think the real risk will be from growing domestic disapproval as the war continues, especially if Russia levels Kyiv. 2/
I don't think the domestic disapproval threat is that high yet, but it will likely grow as the way of life for most Russians is disrupted. Putin's decision to not mobilize the population for this conflict will also likely become a problem as it drags on.3/