Now that the fluff is out of the way, I want to discuss the actual RP. There are several settings for this. It could take place in the United States, Europe, or in China. China wouldn't be interesting in my opinion. The players would just be Chinese freedom fighters. In the US players could only be US soldiers, civilians, or members of the Race. In Europe on the other hand, we could be Germans, British, Russians, The Race, and a lot of things in between.

Therefore I think Europe is the most interesting setting. 

I'm thinking this should be a series of RP's. The first will start just before the invasion and in the first parts of the invasion.