I cant do diplomacy(unless the regent approaches me first.....) or declare war on it,but ive seen NPCs try to take anuire without needing a war declaration and anure can just keep attacking me without a war declaration........whats the deal with this?

Its insane when you have a 10/0 city state sitting in your rear lines perioidcally sending troops to attack you and you cant attack back!

Side note : how do you build strongholds/citadals/fortresses/wizard towers?All i can find is the fortify option which makes normal castles.