Though the AI has handicaps diplomatically as well: hidden bonuses amoungst other AIs, signifigantly higher WFYABTA limit, never requesting they stop trading, etc. Not saying your point isn't good, but the AI gets help there as well.
Though the simple and very true answer is WAR.
And how do you exploit them????
I've always thought one of the main faults in the AI is the inability to successfully capture cities. AI's warring eachother will rarely end up with one of the civs preishing, when it does, the big civ usually manages to do thesame to others, but too often, the AI just war eachother endlessly without making any progress. Looking at the AI trying to capture my cities makes me conclude this would make any war last forever.
That's a paddlin'.It is also highly vulnerable to amphibious war elephants, or at least, that what's I've heard.