Yea it's basically applied game theory because you are never sure if another player wants to cooperate and if they truly mean to cooperate or are just waiting to backstab you once your guard is lowered so you end up competing against others for your own interests even though cooperation is the best outcome.
They don't have much time to backstab you. Once there are several civilizations cooperating, the backstabber is up against everybody else.
Cooperation means you trade your minimal chance of winning a winner-takes-it-all game for the risk of meeting a player who doesn't understand that cooperation is the best move. Given that the other players are space-exploring civilization, I would say that they at least give us the chance to cooperate.
The problem may be that it's not them being evil but us being unable to cooperate.
