So far, I have been impressed with the reason displayed by the AI, but one thing that really irritates me is the AI's desire to colonize every single free square on the map as quickly as possible. There is nothing more frustrating than having the AI build a city on the far side of your empire in that one square of tundra that your cultural borders have not covered yet. Usually all that is accomplished is a short war, that the AI probably didn't want, because it agrees to a peace treaty within a couple of turns. It seems like the AI should expect any new city's workable area to exceed the squares immediately adjacent to it for it to build one unless there is an available resource within that small radius. I find myself producing warriors to fortify in these squares to keep this from happening, but sometimes it is just not possible. I would understand the AI's actions if there were any value to these cities other than to irritate another player. Usually, if I am doing pretty well the city will assimilate into my empire, but I would almost rather raze it since it will never be productive, and my borders will eventually encompass that square anyway.