The US dollar will always be the major currency of the world. What should replace it? The Euro is a good valuable currency, but we lack the military power that secures the US dollar plus we suffer from internal issues like the Italian debt that threatens to destabilize the Euro once again. Japan is a major economy, but still small and it has issues because its backing by the government is uncertain after "Abenomics" and the gerontification of Japanese society. The Chinese currencies suffer from cashflow control measures, and who the fuck would buy anything from Russia even if they had more to offer than barely functioning tanks, oil, gas and grain?