If we start from the principle that everything makes sense, there is a hole here - this war makes no sense. There's no upside for either Russia or Putin. It follows that we are missing something. I have no idea of what we are missing, but I'm sure "Putin is an idiot" is not the most plausible explanation.
Basically: Russian people and territory re-unification before letting the cultural erosion making it impossible, which is seemingly insufferable.
Then there is some rambling about a new order due the coordination of Ukraine Bielorussia and russia would make Europe autonomy crumble.
Then the world was expected to be in awe in such a display of power, and that would have made all countries realize that west dominance is in jeopardy.
1. Putin is almost 70 and there are reports he is making decisions differently than he did in the past
2. He's surrounded himself with yes men
3. Those yes men told him Europe wouldn't do anything and Ukraine would fall quickly. They told him it'd be another Crimea
4. Once the war started it became obvious they made a terrible mistake, but now Putin's stuck in a clusterfuck of epic proportions for Putin, Ukraine, and Russia.
So, what are we not seeing?