Either the EU manages to step in and largely fill the gap, or Ukraine will have to give in. Russia can then ingest Ukraine, continue to seed political distrust in Western countries and then potentially start another war in Europe a few years later.
Alternatively, the NATO/EU/US may decide to become directly involved in the war in Ukraine to avoid a further destabilization of Europe. In that case, Russia can be beat, although I’d expect Russians to be more motivated to go into war.
I’m not sure whether the way the war against Ukraine plays out has too much influence on whether China decides that it needs to start a war against Taiwan though.