People underestimate how harsh this world would be. Yes the garleans have little right to do what they do from a moral ground, but if we're talking purely on logic then yes they actually do because say they were living on the same continent as the xeala tribes, ala mhigo or even Doma. If they encountered the garleans before they gained any advantage they would probably have taken advantage of the situation and conquered them instead. The only reason they have run afoul with the rest of the world is because they ultimately won and were the ones who got there first. These political scenarios often reflect the real world and this is how it always has been, one nation will take advantage of another if the opportunity arises and that includes the modern era.