At this point it looks like Russia will be the next imperial world power although they are certainly doing it differently than other empires of the past. The Euro-Asian Union is likely to officially hold the crown but as we all know, the size of Russia will mean that it dominates in that Union.
Of course, that empire too will run its course and I wonder if humanity can continue on the road paved by Russia. First, it was the Russian people who ended the Soviet Union and that was a remarkably peaceful event because Russians actually don't like wars. Next, the way that they are building the EAU as a partnership based on the model of the EU holds out some hope that it will be an empire that is less willing to throw its weight around globally. And finally, there has to be an end to empire. We humans have to learn how to share this planet under a different covenant than the one given to us by history. The EU is an example that all countries need to emulate, not by expanding the EU but by applying the EU principles in a broader more global way so that countries are no longer sovereign, but are subject to some sort of regional federation which mediates political and social affairs within and without the countries in the region.