They must have played their hands wrong horribly. It is hard to believe they did not manage to find one solid ally. Maybe they overestimated their abilities.
Seriously. Doesn't seem like it'd have needed much to at least make it a tie, and there are a number of realms that would have been unlikely to suffer much (if any) retaliation during the course of the war, due to Westfold being a nicely placed meatshield.
