[Arnt]

https://nitter.nl/kamilkazani/status/1498377757536968711 is probably what you want. And the super-TLDR is that Putin is worried either that soldiers based in eastern Ukraine could invade Russia, dash across the Caucasus to the Caspian Sea and cut Russia off from important blah blah blah, or that Russians could see that Ukrainians are like themselves but have a better state and a better life, and grow restless with the Russian state or both.