IMO, this war is primarily between Russia & NATO because:
"On February 8, just weeks before Russia’s invasion, Mr Putin said Russia’s three main three security demands were no more NATO enlargement; no missile deployments near its borders; and a scaling back of NATO’s military infrastructure in Europe to 1997 levels."(source the New Daily)
Had NATO been willing to negotiate then (it had 6 months to do so while Russia was amassing troops on the Ukraine border and in Belarus) , the following could have been avoided: -120,000 Ukrainian deaths -Over 6 Million Ukrainian refugees -Ukraine Industrial heartland wrecked -20% of Ukrainian territory occupied -Ukrainian Economy and infrastructure wrecked
Collateral Economic Damage: -Europe on the brink of Recession -Strengthening of China vis-a-vis USA -Driving Global Economy closer to Recession (including Aus)
And how will this war end? IMO via negotiations where the above Russian concerns will feature prominently