The National Federation of Earth (or "NFE" as it is mostly called) is a diplomatic/counter-terrorism organization formed by the Humans on July 4th, 2198 as a response to the Vomosh, who were on the opposing side of the Plutonian Civil War. After the war ended, the NFE became Earth's official peace organization that had great success in diplomacy, but had been forced to use its military divisions in certain situations.
The National Federation of Earth can be compared to the North Atlantic Treaty Organization (NATO).
Before the Plutonian Civil War began in 2198, Earth and Pluto had a stable trading partnership where each planet received elements and resources from each other. Although, this trading partnership ended when the Plutonians became ensnared in a deadly civil war that was brought on by a selfish monarchy that wanted a social class system brought on to the Plutonians. The colonists were not happy and started an uprising; however, some Plutonians sided with the monarchy and the ones who wanted freedom had no choice but to fight their own. This caused Earth to be caught in the political blowback due to their loss of Pluto's precious resources, which were used for the creation of ionized shields, heavy weapons and engine cores.