Two years on: How will Russia's war on Ukraine end?

As Russia enters its third year of war against Ukraine, we need to ask: how will this war end? Let us firstly revisit Emeritus Professor Paul Dibb's ANU Public Lecture in August 2022 when he set out the reasons why he thought Putin went to war.
1. The catastrophic collapse of the Soviet Union in 1991 and Yeltsin’s recognition of a separate country called Ukraine.
2. Putin’s belief that there is no such country as Ukraine.
3. Putin’s view that NATO’s expansion to the borders of the Soviet Union is an act of aggression.
4. Ukraine’s ambition to be a member of NATO is seen by Putin as a first-order strategic challenge to Russia.
5. Putin has now proclaimed a new strategic threat: the West is seeking to destroy Russia and Russia is now fighting for its “very survival.”
After revisiting these accusations, let us examine first, how the military fight is changing and what its prospects are for winners and losers; second, what are the possibilities for a ceasefire and negotiations aimed at an enduring peace; third, what are the risks of this war extending further into neighboring NATO countries; and fourth what are the implications for China’s attitude to using military force against Taiwan?
Finally, if the aim of the US and its NATO allies is to “defeat” Russia how will this be achieved against a country with 1500 strategic nuclear weapons? And what would a defeated Russia look like? A Weimar Germany? Or can we conceive of other outcomes under a new Russian leadership?