The last two people that wanted to challenge US dollar dominance in the world financial markets were Saddam Hussein (wanted to trade oil for Euros instead of USD) and Muammar Kadafi (wanted to trade oil for gold). We all know how that ended for both of them - their countries were invaded in under 6 months after they announced their plans.
Now, the only country powerful enough to force switch from USD to currency basket is China, and their recent initiatives, like creating AIIB bank, or devaluating juan are aimed at exactly that.