Relationships with other AI players has been dumbed down to the point where all I can really do with them is go to war ... I can't get fair trades out of them, my cities won't make trades with them if I have open borders and free trade, they won't ally with me because of my social policies or religion, I can't use spy units to interact with them, I can't establish franchises for my corporations in their cities ... no, all I can do is go to war with them, occasionally sign a research pact, and get one-sided trade deals out of them if they don't hate me too much.