This is a trend; look at Persia, Rome, Alexander's Greco-Persian empire. These civilisations who attempt to unite all nations under one banner and take over the world; they will always fail. Persia was taken by Alexander. Alexander's empire fell apart after his death, and Rome rose. Rome was inevitably sacked by the Slavs, the Goths and the Huns in the 5th century AD. And what are the civilisations that work so well? Well, Greece. Precisely why did it work so well? Because it wasn't an empire; it didn't even exist. What we know as "Ancient Greece" was a collection of city states - poleis - that were self-ruled. They worked because they were independent and they flourished because they borrowed from one another. I've used the example of Sparta many times before as a polis that did not flourish. This was because it was a xenophobic state; it refused to take from other cultures, and thus destroyed itself. However, that is a bitesize of Greece. There were hundreds, maybe thousands, of city-states which certainly did flourish. And they were all indpendent. When someone like Alexander comes along, he can only mess things up, because no one individual can rule an empire alone, or even with a small council. You might argue that, currently, the example of the Russian oligarchs shows how it can be ruled by a select few. But look at Russia. It is in a shit state. Hence, my point remains.