That was my instinct too, I'm not saying it's wrong. Just that we need to think. We only had the context of a week. I, for one, didn't get any history on the Atlanteans and the Sirenians previous conflicts; we don't know the Sirenian's reason for waging war.
Everybody's got a reason, it might've been a good one. It might've been that the Atlanteans had done them worse violence in the past, was continuing to be violent or oppressive. Maybe we just crushed a rebellion against an oppressive regime. Or maybe they just wanted the Atlantean land and resources for themselves, in which case we did defend the underdogs. Not saying we did the wrong thing, just saying I don't know, and that's what bothers me.