[throwawayffffas]

Pragmatically I am pretty sure the western logic goes like this. Sanctions will cause economic damage which will lead to misery which will lead to unrest and finally the toppling of the regime. This worked in the 20th century but took like 50 years, and as we can see now the resulting regime is not much better for the west, but I don't think there are any better options. The other approach see China is also slowly blowing up in our collective face, not that it would be an option now.

[pydry]

Pragmatically I think the western military logic is that sacrificing Ukraine to Russia is entirely worthwhile if it breaks Russia too.

They want Russia out of the way so that they can focus on taking down China. Most of all they want to avoid a Russia-China military alliance.