The Watchers (WAT)
Regardless of what the GA and AP say, the Watchers truly call the shots in the galaxy. They've been able to travel through space long before the other factions, but their policy is strictly hands-off when it comes to uncivilized worlds. This rule extends to the other factions of the galaxy, whether they like it or not. Ever since they laid down the law with the cancellation of the exploratory jaunt to the Forbidden Zone, galactic forces are forbidden from contacting a race which has not discovered BioWarp drives on its own. Their reasons for this are unclear to anyone but the Watchers themselves, but most speculate it has something to do with the existance of what are called "Altearths": planets that all are inhabited mostly by humans, all call themselves "Earth", and are in many other ways eerily similar, such as sharing the same languages, landmasses, and histories, with slight variations. These worlds are strictly forbidden, by the way.
The one thing that should be remembered about Watcher fleets is that you should keep yourself away from any situation that would get you in trouble with them. That means to stay away from uncharted systems and never, ever go near the Forbidden Zone. Their patrol ships alone are able to take out entire battle groups, and you're given one five-second warning to get away before your ship is hulled.