SpartanKiwi wrote this awesome HFY story titled The Eight Nations of Terra. HFY (Humanity, Fuck Yeah!) is a subreddit for all media exhibiting the awesome potential of humanity. They welcome sci-fi, fantasy, and all other stories with a focus on humans being awesome! This particular story is about an intergalactic war and the eight superpowers of the Sol system:
Source: SpartanKiwi
A bit heavy on the regional stereotypes, but the uniting against a common foe is spot on.
Hella good story!
A neat concept and love humanity uniting stories, but some of those stereotypes are a liiiiittle offensive, just saying.