Isn't there ample evidence that Ukraine's been forcibly conscripting citizens, many of whom are ethnically Russian and don't feel that motivated to fight against, well, Russians?
Look at a demographic map. Ethnic Ukrainians are in the northwest, ethnic Russians are in the south and east. Guess where Russia is attacking?
Didn't Ukraine literally just launch missile/artillery attacks at random civilian targets in Donetsk... The same thing they've been doing for almost a decade?