>>212923509 (OP)If in short:
Ukraine is fail-state since collapse of USSR but has big population, lots of land and good geographic position so there are lots of foreign interests towards them
Russia is dictatorship established after "democratic" revolution so its president always chimping out to prove he's great historian figure and not a banana republic dictator like Lukashenko
The war will end only if either western powers directly enter their forces in ukraine so Russia switches to defense or ukraine change it's ideology from "anti-russian" to something different