Question about Alliances

You're supposed to be able to deal with the alliance as if it were one big unified empire. But it's not working right.

I can't think of much that will help, but don't let the alliance spread - it'll only get worse. Take them out if you must, or work to keep them from getting cozy with the other AI's.

Since it's not working right, the alliance members will (if they share any systems) grow to hate each other and it may break up on its own. But take no chances.

If you're big & dominant, you might gift some junk planets in the same system to the alliance. If they accept, the planets should go in turns one to each member - then they'll start hating each other that much quicker.

Alliances and their members are unable to make peace (an undocumented feature). They can't make treaties of any kind. So avoid war unless you're ready to fight to the bitter end. Not that there's any other way, really...

If the alliance has more than 2 members, they should eventually kick out the ones who don't have enough votes to keep themselves in.

If you want to see what works and what doesn't, start an alliance of your own. It'll spoil your game if you take it seriously, but you'll soon find out the mix of what's bugged and what isn't.

A couple of patches ago some of the alliance problems were fixed. So maybe the rest will follow. It'd be cool if it worked. But the game might just get way too easy. A big alliance is an economic powerhouse, and let's not mention tech sharing... But a no bombardment clause will mean no offense whatsoever for AI allaince members, and if their enemies aren't restricted it makes for a 1-way war.