@katanon: As I understood it the new *smiley* guy forced a peace agreement onto MC, to stop him from taking his cake. -> Peace
I know he did it to start an invasion himself, so to start a new war, (which would be worse, than what MC would have done to them). Yet still, he stopped the current one, which is a "good" thing.
And with "Who knows, what happens next?", I meant, that for some circumstances, that new guy suddenly might not be able to invade himself. So there is a (very small) chance of no bloodshed taking place at all. For example: He hindered MC to invade. If MC finds a way, to also hinder Smiley McSmile to invade and aims for a hostile (yet still more human) economic takeover (like he threatened to do before), MC would pay that bastard back. (Welp, to a certain degree, that is.) Point is, there is a (small) chance, that the citizens of evil invader land aren't invaded, raped and slaughtered themselves, which would actually be a morally good thing.
Smiles McGee did effectively a "good" thing, from a moral standpoint, even if it was just to further his own agenda (and obviously hide his ambitions behind that good deed).