Hmmkay so I just quit a game where I was outclassed and being warred upon by the two largest races in the game. What frustrated me about this particular game is the lack of diplomatic options.
I was allied to the Terrans, but they were allied to both the Yor and the Drengin. When I was attacked by the Yor and Drengin the Terrans did not help me, presumably because they are allied to the aggressors. Now what bugs me the most about this is that I have no way of asking them to help me out. The option to ask them to attack my enemies isn't available, i guess because of their alliance. Wouldn't it make more sense to leave that option in place but make it more difficult (cost more) to actually get their aid?
I find a couple of things pretty annoying in the way alliances play:
a) if 3 races are allied and race 1 attacks race 2, then race 3 should automatically break their alliance. Not necessarily go to war, but not stay friends with race 1.

why are the terrans allied with the evil Yor and Drengin anyway? These races have consumed a couple of other races each, I'd think the terrans would be making an effort to work against them.
c) why do the Terrans come to me and complain that the Drengin are getting too powerful, yet they won't trade techs or anything to actually work with me against the threat? They want a dozen good techs for one of their techs even in the face of drengin's rising power that they're oh so worried about...
I just don't get a lot of how diplomacy works in this game. Seems like the "oh nooooo we're all going to be eaten by xxx race!" messages from other races should actually mean something.