I think there's a catch 22 on peace treaties and alliances. In my last game (small galaxy, 3 AI, I had an alliance with the Terrans and was at war with the Drengin. They asked me for peace and I agreed. The very next turn they attacked my ally the Terrans. I was forced to choose to take a diplomacy hit for not keeping my treaty, or a diplomacy hit for declaring war on the Drengins... either way I was toast. I choose to honor my treaty with the Terrans, since I had research and an economic treaty with them, and they were in dire straights. About 5 turns later a megaevent gave the Terrans superinfluence. Suddenly I was going banckrupt paying on all my worlds and resources, so I HAD to build influence SBs at every world to keep from being culurally dominated. Needless to say 15 turns later I got the secret meeting megaevent where the Terrans allied with everybody except the Krynn and wiped me off the galaxy. I still saw the Drengin empire crumble under the Terran's influence