One of the more annoying aspects of the AI when it comes to warfare is how it handles defensive civs. If they attack a well entrenched player and lose spectacularly, they will often continue the war until the player gets sick of it and goes on the offensive. Basically, the AI has trouble recognizing when a war of aggression is a lost cause. They will continue sacrificing units against the walls of a player's city until the player builds up a bigger army and attacks. In theory this might make sense, but in practice it's too late. A half decent player will build up his army, wait for the suicidal wave to attack his city and then counter attack the now defenseless civ. When the AI finally sues for peace at this point, it's laughable because he's screwed. My suggestion for the upcoming expansion is to give the AI the ability to keep track of his losses versus the enemy losses. When they reach a certain threshold he sues for peace. And I'm not talking about the "give me 4 of your cities and all your gold" peace.