the plot of Mass effect.
humans build a space station. And a fleet. First contact with Turians. War. Humans fuck their shit. Turians WERE the army/police of the Citidal. We fucked up their shit. "oh, so you all have been space faring for 5 thousand years? oh, thats cool. We've been in space for 50 years. Give us a spot on the council, reserved for 3 of 100 known races, and us now. Also, we want total control of the military. Also, when giant robots attack? we are taking total control, after we let the council die.