To add insult to injury, when you do eventually take the city you'd be better off razing it to the ground and start anew due to unhappiness/courthouse maintenance. I've said it before and I'll say it again: the ciV AI only has three states: scheming, hostile, and WAR. Naturally (in this game, anyway), relations can only deteriorate.. In my opinion this issue is nowhere as bad as the accusation of "massing army near our border", triggered by their scout moving around my army inside my border. Most of the time I don't even know their location on the map. And of course, declaring war decades afterwards brands you a liar.