stealth_nsk
Deity
It also means you have to eventually attack your allies, which is silly. Even the nastiest conquerors in history had friends.
It wasn't a huge deal in Civ V (because it's virtually impossible to keep friends), but I was hoping for more diplomatic possibilities in Civ V.
I hope there's some form of diplomatic domination (some late-game form of vassals) where you could be counted as "controlling" your ally without having to actually conquer it.