In 2014 a bunch of Ukrainian nazis couped the democratically elected government and started ethnically cleansing the Russian population in the Donbas. Some sections of the Ukrainian military rebelled and formed militia units to protect the population from being murdered by nazis, leading to a low level civil war stretching on for years. Ukrainian nazi paramilitaries continued persecuting ethnic Russian Ukrainians civilians as well as shelling Donetsk and Lugansk

During this time Russia tried repeatedly to conduct diplomacy with the nazis western handlers, the US and the UK, as well as interested third parties such as Germany and France. However, it was pointless as the US never intended to back down and continuously goaded the Ukrainian nazis into attacks on the Donbas, all the while supplying them with money and weapons. When the war seemed to be escalating to the point NATO forces might join in, Russia - understanding that any actual direct combat between Russian and NATO soldiers would lead to a global nuclear holocaust - jumped in with its troops first… after spending three days voting to formally recognize the independence of the DPR and LPR, of course, because Putin is a bureaucrat to the core and these things must be done properly.

And now, the people of Donetsk and Luhansk can live quietly without fear of nazi missiles blowing up their city centers for no reason.