My take on this situation:
From The West perspective (US, EU)
- This is a proxy war between the West vs Russia
- Putin may kill Zelensky and take Ukraine, but that won't be the end of the war. The guerilla war if it comes to that point, will rage on for years, bankrupting Russia. The West will keep supplying weapons and ammo and foreign fighters while choking Russia's economy. The ultimate goal is to oust Putin and to install Western democratic government
- Installing pro-Western democratic government will give them two huge advantages, weaken North Korea and weaken China, as Putin's Russia is one of their strongest ally
- Winning this war will give them a blueprint for China-Taiwan situation and serve a warning to China
From Russia's perspective
- Sadly for them, there's no win scenario
- They will not win the proxy war against the unlimited resources of the West. Tens of thousands foreign fighters with fresh ammo will keep pouring into Ukraine
- They go from sitting equally with everyone, to becoming China's bitch, as they will totally depend on China
- If they trigger nuclear missiles, they will be wiped out. Putin may kill tens of millions of European but Russia will cease to exist
From China's perspective
- They don't want either one to win this war, the longer it goes, the better it is for China, as both sides will go on years with economic uncertainty and instability, weakening both sides. So they won't fully support Russia, and on the other they also criticize the West