I of course have not seen Sacred Honor, but from what it sounds like, the writers probably focused solely on the US (or what's left of it) and didn't bother too much about the rest of the world, only including information if it pertained to the story. It would be really cool it were made it into a series, or at least set some other movies in the same world.
I would imagine that the popularity of Sacred Honor would spark sequels and spin-offs.