Oh deal the model-maker and wargamer's concise History of the World.

"China might well be the next predominant Imperial Power" - Think so LH? Oldest "Empire" in the world, never amounted to much because it has far too many internal problems to worry about. That continues to be the case for its current set of Communist "Emperors and Mandarins".

Odd that you should ignore India, potentially far, far more powerful than China.

So Persia fell to Greece. Greece (and many others) fell to Rome. Rome fell to its own internal corruption and to barbarian invasions. But not a word about either Charlemagne or Genghis Khan, strange.

"Much later Spain was the great imperialist of the world, but they fell from prominence after 1588, and Britain became number one for a long stretch."

Naw LH, there were quite a number of "Imperialists" toddling about around this time, you really should read what occured after the death of Charlemagne. There were two "Super-Powers" in Europe at this time France and Spain, you also had the Holy Roman Emperor whose progeny would create what would become known as the Austro-Hungarian Empire, in terms of overseas exploration the Portuguese were also in there pitching. One thing is for certain Spain was not all powerful. Another really significant player that you omit from your list the Ottomans, what about their Empire LH. So you see it was quite a melting pot with no defined "cock o' the walk". England and The Netherlands around this time were opportunistic small timers, and it would be a long, long time after 1588 before the British Empire took form and centre stage.

The British Empire, like that of the Dutch and the Portuguese grew from trade not conquest, which is why it lasted and which is why there is still to this day the Commonwealth of Nations. France under Napoleon, attempted to forge an Empire by force of arms, he was not defeated by a coalition of those he had alienated as you put it LH, he was defeated by an alliance of countries that he had invaded - big difference.

The Tsarist Russian Empire? That was an implosion that brought that down, a failure to move with the times. German attempts at "getting a place in the sun" and later attempt at "Leibenstraum", were the same as Napoleon's grubby little local smash and grab, and just as short lived.

Post WWII, you had the US and the USSR, with their respective "spheres of influence". The US tied those to her by economic means while the Communists of the USSR under Stalin had a bit of a different, and more direct way of keeping people in line (Hungary 1956 and Czechoslovakia 1968 are examples). Afghanistan had little or nothing to do with the collapse of the USSR, the final bullet to that Mastadon's head was Iraq in 1990, when the people of Russia saw the lie they had been sold for forty years exposed for exactly what it was.

"..the Anglo-American empire now saw that there was no counterbalance left in the world against them and they felt free to rob and take over anything pretty well anywhere in the world (except within China). So they did. And they have been fighting a series of their own chosen wars in a series of places where they see something to gain." - little hawk

Interesting theory but in reality a load of biased and emotive bollocks.