Here’s an Appropriately Detailed Homefront Timeline
Homefront was written by John Milius. We know Milius because he wrote Red Dawn. (Others know him because he wrote Apocalypse Now and Conan the Barbarian and Dirty Harry.) Red Dawn had a ridiculously long pre-title explanation of how it could come to be that the Reds invade the US without having their asses completely and utterly kicked. We didn’t really need it, though, because the Soviet Union a big place and has a lo of people in it as well as a beefy army.
Homefront is basically Red Dawn with North Korea taking the place of the Traditional Reds, and so we actually do need a really long backstory to explain how the hell they could conquer the US. North Korea only has a total population of 24 million, after all, and is a small place that has few resources. There’s no way the North Korea as we know it now could occupy and keep a hold on the USA for two years, as happens in the game.
At E3, THQ released a timeline trailer of sorts to set up the story (which I’ve embedded below because it’s bitchin’), but now they’ve gone and put up a whole section of the game’s website to explain it all through videos and some text and things like that leaflet pictured at the top of this post. It’s not the Wikipedia model, certainly, but it’s more fun. So head over there and check out a plot only John Milius could ever get anyone to take seriously.