Russia has a paranoia...Is not an excuse any intelligent person would use as an excuse for Russia invading Ukraine.
Perfectly reasonable argument that Russia miscalculated big time. I do think the action has cause though. I would feel way better if action was just to protect Donbas, and nothing more, but here we are. Put it this way, their justifications were more legit than either of U.S. invasions of Iraq, or the NATO bombing of Libya, or the attempted overthrow of Assad in Syria.