This is an excellent in-depth analysis of the Ukraine situation. From John J. Mearsheimer at nationalinterest.org:

The war in Ukraine is a multi-dimensional disaster, which is likely to get much worse in the foreseeable future.
Let me now turn to the matter of escalation. It is widely accepted among international relations scholars that there is a powerful tendency for protracted wars to escalate. Over time, other countries can get dragged into the fight and the level of violence is likely to increase. The potential for this happening in the Ukraine war is real. There is a danger that the United States and its NATO allies will get dragged into the fighting, which they have been able to avoid up to this point, even though they are already waging a proxy war against Russia. There is also the possibility that nuclear weapons might be used in Ukraine and that might even lead to a nuclear exchange between Russia and the United States. The underlying reason these outcomes might be realized is that the stakes are so high for both sides, and thus neither can afford to lose.