After the US overthrew the elected Ukrainian government ,in 2014 I believe, that was sympathetic to Russia the new government started killing their own people in the Donbas region who did not agree with the US involvement in their elections. Russia only got evolved to protect them. There is a lot of history here Iām not sure you are aware of.
Discussion
Yanukovych was not sympathetic to Russia, he was neutral. But that was not enough for the west. Whoever was not on their side was an enemy.