Waking Sands - Explain to me please (Spoilers)

[Enkidoh]

Actually Garlemald's 'peaceful union' was in fact a demand to the Eorzean Alliance to surrender themselves to the Empire and become vassal states - effectively to become like Doma and Ala Mhigo, only without a a single shot being fired. Needless to say, this never happened (mostly due to the timely arrival of Minfilia, Alphinaud and the Warrior of Light ).

As for whether Garlemald is 'right' in their attitude of conquest, whatever moral high ground they may have had was eliminated the moment that they started allying with the Ascians, you know, the very beings who actually teach summoning.