I dont want to argue, but im pretty sure that there is little to no lore or backstory other than that which fits on one page on either the ps1 or ps2 website.
Compared with something like LOTRO, SWTOR, WOW or any other story driven MMO, planetside does not have anything resembling a rich storyline (with books worth of lore with quests to back it all up).
Its designed to be sandbox, and I the stories are created on the battlefield
[Edit: And I don't mean this as a bad thing, its just not that kind of game!]
Nubb, Nubble, Nubbles
Professional Dutch Rudderer (apparently)
And Guild Leader of PCG The Revel Alliance
(swtor republic guild)