Erm... sorry for resurrecting an old thread, but I have also experienced similar AI behavior.
Are the AI's programmed to gang up against the most powerful nation? In my latest game, all the other civs were trying to wipe me out, and whenever I managed to force peace, they sneak attacked next turn. I think this started happening by the time I was the superpower of the game.
Finally, in 1970, my spaceship reached Alpha Centauri, but I decided to continue playing (not just one more turn
). Everyone was now eager to sign peace with me, and the next 50 years were VERY peaceful. Some small wars between the AIs, but no one touched me.
Well, it seems that this is the way AI is programmed. AI civs also want and try to win the game, by harassing the strongest civ, all fighting for the first place. And when the game is finally judged, they stop being psychos.
I'm just not sure if that only happens when the superpower is the player himself. Do they act the same way against an AI superpower?