Inorder to purchase oil, the transaction has to occur in usd. Therefore all countries require the usd. When another country decides not to use the usd, demand for the usd decreases. When that country then offers to sell commodities for a currency that cannot be printed but is instead tied to an asset, that currency will maintain value. This creats an incentive to transact in Rubles. When we print money, we are able send a large part of it elsewhere where the effects of inflation can be hidden, however when we can no longer export our dollars, they will sit here, further inflating our currencies, requiring more debt to keep the party going as asset prices skyrocket. Eventually hyperinflation ensues. When a currency it pegged to an asset, it can't do that. Russia just did that. All dollar denominated paper assets are fucked, prepare.