We can delve deeper later, when you have time. =) Hmm, I understand that you are a GM and set the rules, but it's not necessary to have an "us vs. them" mentality.

If you wish, you can try to sit on two chairs, risking, however, getting a slap from both. ;) This is only impossible when one set of obligations contradicts another. For example, simultaneous membership in KOSAP and RPA will make it impossible to fulfill the obligations. Or AFTA and FEU.

Although, yes, I just reread Menta, and it's not a security council there, but almost a military bloc: "This could be a direct ban on aggression, economic sanctions, or any other form of deterrence, up to and including international military intervention in the aggressor state."
Then yes, Revan is right. I thought the security council in both cases was more like a platform for dialogue.