Unholy alliance/ Alliance of convenience

Sounds good. The alliance might bring them closer together in the long run, too...... of course, there would be all sorts of "betrayal" options, so people would keep their gaurd up..... much fun!

I like Civ 4's "brothers in arms brings us closer together" or something like that.   If the AI is good at all, faction A will ally with Faction B to take out C even if it doesn't like B provided C is a worse enemy (and mutual, since they wouldn't ally with B against C if B and C are best friends... unless its Sins of a Solar empire, in which case I hate how they are like "go thrash your best friend" all the time)

I like it.  It's akin to the Allies and the Soviet Union in World War 2.

I'd love to see something like this. Temporary alliances with specific terms. Even though we hate each other, we join forces to thrash an even more hated 3rd party but that's it. No obligation to defend each other from new threats or other players, for example, and only limited sharing of intelligence. It would be neat if we could choose what kind of intelligence to share, like any intelligence regarding our mutual enemy, intelligence about our militaries (possibly limited to selected armies, even). For example, we might want each other to know where our offensive forces are for better coordination and such without sharing any information about defenses that we don't think are relevant - basically, sharing information on a need-to-know basis.

I could have sworn I already posted in support of this, but because I apparently didn't: Good idea!

Alliance of Convenience sounds fine to me. However, to me the Unholy Alliance suggests an extremly far-fetched one between two that are polar opposites. To continue with the WWII reference, Unholy Alliance would be to me Hitler and Churchill teaming up. In GalCiv2 terms, it'd be the morally righteous do-gooder Altarians allying with the xenophobic nd genocidal Korath. 

But that would only happen if a third party came a long that was hated by the Altarians and Korath even more than they hate each other, and only if the Altarians and Korath understood that their only chance of victory against this abomination is to join forces. Once that's over (assuming they win) they'd be back at each others' throats - and there would probably be a lot of backstabbing and deception between them even during the conflict.

I'd love to see this happen. For even most hated enemies to temporarily work together against something they both think is even worse, rather than choosing certain destruction by going it alone. Like every other aspect of AI, though, I'd like there to be some randomness, some unpredictability - so even if all the conditions are there, this wouldn't always happen. And it might happen on occasion even when you don't quite expect it to.

For me an "unholy alliance" is any alliance of a weak but devious evil individual and a powerful and eviller force. Sort of like Wormtounge and Saruman in LOTR, or Pettigrew and Voldemort in Harry Potter...... or the Drengin and Dread Lords in GC2. They don't particularly LIKE each other, but are willing to share domination of others.

Space Empires V had a great treaty and alliance structure, which unfortunately suffered from so many bugs as to make it far less useful than it could be.  I think something with that number of options, or even a few more, would be great.

Personally, I prefer the term "Strange Bedfellows" alliance as opposed to "Unholy" alliance.    Regardless, though, I love the idea!  

+ 1 karma for Strange bedfellows,   I think it's a much better term then unholy alliance to describe the deired alliance type.