First, Ukraine was part of the Russian empire for centuries, not decades.
Second, the Ukrainian people will NEVER accept a Russian imposed government.
Third, this war is going VERY badly for the Russians, Each day it seems less likely that the Russians will ever conquer Ukraine. There battle tactics are out dated, they have failed to surround Kyiv and they haven't been able to control the skies over Ukraine. The elite Russian forces were wiped out early in the war, leaving an army of demoralized conscripts that do not want to fight the Ukrainians.
The Russians have in desperation resorted to the Nazi tactics of attacking the civilian population. That will never work. Hitler tried demoralizing the British with the blitz, but that just had the opposite effect on the British people. The same is happening in Ukraine.
The NATO Generals are laughing!!!!