Hi everyone and my congratulations.
What we all saw it did not start the game. Just think about how they learned about the Earth, where it is.
They should have access to information on key planets.
This is not the beginning of the war, if the Earth is lost, then why fight? The biggest motivation - is to fight for their country, if your home is destroyed, then there is no motivation.
Revenge? It's a bad motivation, no inspiration.
Something to fight for, if not for their country? For blue woman, for Dinosaurs turians, NO, they fell the first. Have you seen, in whom shot a sniper? I saw - it was turian hask. And one more note, they have not bombed from orbit, on orbit no ships and this means that they are not trying to destroy the people, they want make Human-Reaper. Every decent, in Reapers opinion, nation turn into Reapers. Their motives are not to destroy, but to preserve decent nation. Why? They themselves, when they were alive, but only so, becoming flesh in metal, were able to continue to exist. Because they know, that others do not understand, They saw the death of not one galaxy, the stars were fading and organic life is disappearing. Such a monstrous way, they preserve decent race.