At the end of Oblivion we watch a flashback to when the astronauts are captured by the alien spaceship. Jack and Victoria are in the cockpit talking to mission control, and mission control says "you are an effective team".
Obviously, the alien spaceship was listening into the broadcast as that phrase is repeated throughout the film.
Did this statement by mission control seal their fate?
We don't know what would have happened had control not said the phrase, but I'm left wondering if the alien has always used native life as a tool or if this was a special case.
The alien was capable of destroying the moon, and using our own nuclear weapons against us. It seems strange that it would be dependant upon Jack and Victoria to complete it's objective.