> The Donbass milita? They have been engaging in various forms of combat with the Ukrainian forces multiple times since the ceasefire in 2015

Both sides are indicating an escalation, though who escalated is in dispute. (Though the motive for Ukraine to escalate when Russia has massed troops on their border and on the same day that Russia recognizes the breakaway republics is somewhat obscure, while the motive for Russia-backed separatists to do so is blindingly obvious.)