2102: Aliens come to earth. Not weird aliens that want to conquer us, they're quite nice, and they use some other alien's technology to raise atlantis.
They adopt a child from Canada, and fly off, returning 20 years later, the child now fully grown and super-intelligent by our standards. Said child assumes leadership over the newly raised island, now named 'Nihiltis' a portmanteau of 'Nihil', the Latin word for 'nothing', and 'Atlantis.
With the child's superior mind, he quickly starts a plan to unite the world under his rule. Don't worry, he's not evil, he's the good guy, that's why he wins.
Using his intelligence and charm to manipulate governments, getting certain key people into key positions before the First Expansion, when several leaders all over the world simultaneously gave up their countries to Nihiltis. And the Empite was formed.
The world leaders were in countries leading in technology, economy and countries containing oil [see Saudi Arabia, Libya etc? They've all got oil], giving the Empire a monopoly over the valuble resource.
Second Expansion, this time the semi-major countries, north African countries to secure trade routes through the Mediterranian. Brazil, the small countries south of Mexico and the Carribean to make sure they have good places to defend against an American attack from. Then there's the countries who joined after seeing the success of the Empire, and who were persuaded in with propoganda.
Third Expansion, smaller nearby countries who want to join, basically, and South American countries to strengthen their position there. Also, disheartened people from Russochina willingly give over several areas at the edges of their country.
And the Nihiltean Empire rules alot of the world.
Then the Russochinese Union attacks the NA, seeing the provinces that are now in the NA's possession as a hostile act.
Fourth Expansion, pleaing with other countries to let the NA help them, they give their countries over to avoid Russochinese invasion. The NA counter attack Russochina, with superior technology and tactics, they easily take over quite a bit of Russochina in one year.
Russochina surrenders, and the two superpowers formulate a peace treaty.
Oh, and through mediating through the Union of North America, Canada and the USA, along with the UNA form into the United Republic of North America.
And so the world is divided up between three superpowers, all peaceful in their hating-each-other-ness, at least, peaceful for now...
Please note that some of the changes on the map do not happen, e.g.: Spain and Portugal never became one country, neither did Ireland unify into one country, Brazil is still one country as are Burma and Thailand. Although, this is all subject to change.
Also, I made some flags that I quite like, sorry they're a bit big.
Russochina:
The United Republic of North America:
Note the extra stripes in blue, and extra stars.
The Nihiltean Alliance:
Oh, and a map after all I described happened.
What happened between now and 2102 [First Contact] is subject to change, but after it happens, the above is, at least, a vague description of what happens.
Sorry for the long post and big pictures.