This is the best tl;dr I could make, original
reduced by 92%. (I’m a bot)
The Kremlin spokesman, Dmitri S. Peskov, said Russia would intervene to prevent ethnic cleansing of Russian speakers by the Ukrainian government, a risk he compared to the ethnic massacres of the 1990s Balkan wars, though there are no signs that such violence is imminent in Ukraine today.
The front line in Ukraine, in contrast, separates villages and towns comprising a similar mix of Ukrainian and Russian speakers, with no significant ethnic or sectarian differences.
Russian officials have said Ukraine, not Russia, initiated the escalation.