Some intelligence from a reputable source which may shed some light on the Ukraine situation:
The Donbas is a region that was annexed from Russia in the fifties, all ethnic Russians and Russian speakers. Donets is the main city. Since 2014 there has been a separatist uprising calling for the region to rejoin Russia. The rebels have held the towns for 8 years and are totally dug in.
The Ukrainian army has been at war with the separatists for 8 years, a proper war with huge casualties. The separatists hold Donets and have their own regional governments, the same regional governments that asked Putin to recognise them as Russian enclaves. He did, moved into them, stopped the constant shelling by Ukraine and this "war" started