Greetings civ fans... So I was just playing civ4 (normal, emperor, small map, 8 civs) and at around 900AD my best friend (+8/-1, pleased, Mao) turned around and declared war on me. IT was so outrageous I had to find out why the AI would do that, but searching around here I can't seem to find any good guides as to what caues the AI to declare war. Any thoughts? Mao and I were best friends. We're the same religion, have some good resource trading going on, open borders, ...etc. He is the most powerful nation of the 5 on my continent, and I am the weakest. The little bit of info I've been able to find indicates that maybe he declared war simply because I was so weak? Is that AI really that poorly programmed? Everybody else in the game so far (I've met 4 other civs, including Mao, on my continent) likes me except for Tokugawa who hates me with a passion. Is it possible that Tokugawa was able to bribe Mao to declare war on me? Right before he declared war, the foreign adviser indicated that Mao disliked Tokugawa, and Tokugawa had very little gold for trading with me, so that seems highly unlikely.