Going (painfully) back a few posts ... talking about Putin being "cornered" is rather unhelpful. Yes, I know it's meant politically etc ... but the comparison is, of course, with an actual physical position. (See the helpful picture of a bear earlier.)
Now look at this map of Russia:
View attachment 869
If Putin were to retreat from that bit on the left labelled Ukraine, is "cornered" how would you describe his position on this map?
I don't see any viable threat from his neighbours to living a peacable life within that big orangey-brown area.