[@Bishop] If Jack dies he has no guarantee that the royal blood dies with him nor can he even be sure that a loyalist with no true claim to the throne will step in. If anything, it wouldn't be a Jack loyalist and if there was no heir then Slibah could and likely would become a puppet state. Or there would be conflict as various houses vie for the position. Does Jack honestly think some guy who supported a terrible person and a worse king would sit the throne for any meaningful period of time? What's stopping the people from using Jack's death as a means of revolution? They're surely not happy with him as is. If anything, so far Maddox seems far more reasonable by virtue of the fact that he's [i]not a raving lunatic that murders people for no reason[/i]. Jack dies and the control he has dies with him. 

If Jack is put in prison it's not an act of war. An act of war would be threatening Jack or else harming him or things in that vein. Jack coming in and murdering civilians or else doing harm to the foreign lands is [i]Jack[/i] doing actions that could be taken as a declaration of war. Jack is a guest, technically, and shitting on the carpet is not going to do anyone any favors. You think that Jack being punished for his actions will spur the people to war because their king is a fucking asshole who thinks he can do whatever he wants? 

Jack isn't a godking, especially not in a territory that doesn't belong to him. 

But let's assume that arresting Jack for crimes (hypothetically) starts a conflict. Slibah would be heavily disadvantaged because they'd be down a king and it's not as if the army is full of loyalists. It would create a vacuum and do more harm for Slibah than anything else. 'Loyal to the country, not the king' is a sentiment I'm sure is shared with a good number of people in Slibah. 

It is an empty threat because Abhain can wait for Slibah to implode and swoop in and end the long standing conflict in the chaos of a power vacuum. There is no possible way that every single man, woman, child, and soldier is loyal to Jack. And what are the accompanied men in Abhain going to do if Jack fucks around and makes things bad? Fight the fuckin' army on their home turf? Good luck with that. 

Jack is a terrible king and he'll be even worse if his plan is "Yo I'm gonna kill some of your people, Maddox, but don't do anythin' in response or it's war, k?" He's not the fucking Joker and inciting chaos and calling it a plan.