A sophomoric - and perhaps dishonest - child leads with insults without following the dialogue and grasping context, if able.
Does that sound as if I don't understand Putin's alleged concerns? Well, no; I plainly counter that his concerns are not practical to the point of sophomoric, childish and dishonest absurdity. I repeat; Russia has no security concerns regarding Ukraine. Do you understand the context now?
The post you quoted; you omitted a telling quote from Putin re: invasion without Security Council sanction to be a violation of international law. That should have given you pause.
I've also laid out that Putin does not recognize Ukraine as anything other than Russian, an artificial forced construct, and has stated dissolution of the USSR was the greatest catastrophe of the century. And how he has used that, along with his statement bemoaning Russian citizens disconnected across the former satellite states as a great tragedy and that Russia will protect them wherever they are, to prop up separatist groups within those states and do exactly what you state he fears; destabilizing those countries. In Ukraine, he's fighting 'Nazis'. You may think he believes that, and you'd be a useful tool.
If not following the conversation to date, you may at least inquire before piping off with insult next time. Or not; either way suits me.