Perun gives a pretty good review.
The one thing I might quibble with is his assessment of Russian political objectives. He says it was to demonstrate Russian army invincibility but it may be Putin launched this with a notion that the pecking away of nations within Russia's traditional sphere of influence needed to be disincentivized. That is an aim that may not be "completely smashed", contrary to the author's assertion that ALL Russian political objectives have been.
If the aims are completely smashed the Russians will soon quit. If not they will continue. Seeking, whether or not they win or lose, to make it a costly affair. That goal may be viewed as achievable if they can make it to and through winter. Ukraine is now nearly totally mobilzed, some say they have a million-man army now. This means there's a million government employees to feed and house instead of working jobs and paying taxes. The West will fund this but will also feel some pain from that and that pain may cause politicians to think twice about dispatching Kagans and the like to foment revolutions in the future, and that won't be the case if they up and quit quick and in abject humiliation, so they will seek "peace with honor", a political goal, unless forced otherwise.