Lets be honest here... the G8 is a joke. The US is the only really important member (and the US is in decline), most of the rest are just a bunch of historical has-bin’s.
Russia could form an alliance with China alone and tower over the remaining G8 countries.
Russia and China could form a economic pact and decide simultaniously to switch away from the US dollar as the their reserve currencies...
Which would instantly destroy the US economy.
We are in debt up to our eye-balls and they hold all the cards.
Tower over them using what metric? Death by alcohol?