1) Massive Natural Resources (carbon fuels) which mean they don't have to do anything productive and can make huge money.
2) Totalitarian with Kleptocracy. The population accepts it over anything else, Putin keeps all competitors at bay. This means a single cabal can make big decisions.
3) Cultural Chauvinism. 30% are 'totally cool' with wiping out their neighbours in the vein of some cooked up rubbish. Even when they know it's 'cooked up'. I think they are definitely product I don't think they see themselves as 'ubermench' I think it's a kind of 'superiority from an inferiority' complex. They also lack empathy compared to most other places, not on an individual level, but on a cultural level. There are no leaders who speak of hope, togetherness, prosperity - those are viewed as 'weak'. (Paradoxically their 'strong' people are just incompetent killers).
So with Money, Control, and Cultural Chauvinism - you have potentiality for big things. Like war.
'Security Council' is not that important.
Nukes are actually not important - but they do provide an 'umbrella' of cover, in that, NATO would already be in Ukraine otherwise. So they can be decisive.
Their 'former empire' is not relevant other than in the jingoistic psyche of Putin and some of the plebes.