If you aren't afraid of Darka, the strongest realm on the continent, then you're stupid. Ignoring the capabilities of their army, and their track record of performance is stupid. People don't hold grudges against incompetent realms, because that incompetence prevents them ever creating a situation for a grudge to be formed. Holding a grudge against a powerful realm, is stupid unless you can hold your own against them.
The ONLY reason it is even viable to discuss a war between Coria and Darka is because its not even remotely 1v1.