Most of Azeroth is controlled by Trolmanian Empire, which controls all of the northern Eastern Kingdoms and is occupating Kalimdor and Khaz Modan. Concisting of humans, high elves and all the races of the lands captured, it is the most illogical force(except hippies) as all the races including night elves who lived for thousands of years worship the "God Emperor" Trolman without any tries of rebels or uprisings. Also the most overpowered force as you can imagine.
The rest include Sea Legion(water races), Arathor(humans of Stormwind), Fearless(undead of Northrend) and various merchant players. Also there are many forces created but not controlled by players, such as Chaos forces for example, controlled by VeljkoM, but not being his force.