The Russians should have just stuck to some classics, like “we need breathing room” or “Ukraine has WMD” or whatever.
Or just have been honest — the Ukraine has a bunch of oil and gas recently discovered and Russia needs to protect its market.
Oil reserves in Donbas region: drilled in 2014-2015, not economical, some fracking, but poor quality. Russian propaganda that there is lots of oil in the region.
Ukraine not self-sufficient in oil, imports mostly finished products. Large natural gas storage ESE of Lviv - largest in Europe.
That's the crux, of it.
“The Russians should have just stuck to some classics, like “we need breathing room”...”
Well, Lebensraum had already been used, and the Russians were worried about copyright infringement.