The country flags are used just as a general association... conceptually the world is at chaos and many of the military leaders are spawing at different places (may be with in the same country) and claiming they are ultimate leader... the countries as we know it, does not exists in the game world.
We may consider the flag level leader board in the future... but as of now since most of the players are US based, it may not be fare enough competition.
Ok I understand. Thanks for replying. And keep up the great work. :)