Sorry, I didn't get it. You say geographic is one of the reasons, as far as I now Russia had already access to the black sea before the occupation of Crimea.

Okay better access to the black sea is probably better then less for Putin, so that is a explanation.

But it doesn't explain, why Russia can't survive with the size before 2014.

The same to demographics. China has bad demographics too, it will not be solved, if they dare to occupy taiwan.

Maybe a better explanation, I usally don't like that explanations, is, that putin is stupid.