Jotunheim has deceived his ally, C'Tis. While C'tis was led to believe that his ally Ermor was almost dead, and that C'tis needed to divide the spoils, Ermor was far from dead. Therefore, a state of war exists between the nations of C'Tis and Jotunheim.
Thats a truly nice way of making diplomacy - once you see you neighbour on the loosing side you grab his provinces and now you claim you were deceived... tstststs.
But come on, we have no fear of little green animals who smell like fish.
Well...maybe....just maybe....that was planned from the beginning. To lure Jotunheim into Ermor's clutches while I denied you access to Ermor's other provinces, all the while using the old hammer and anvil approach!!!