I don't know, sometimes we take the factional oppositions and tensions too seriously I think. There has to be SOME inter group peace for the economy in Sirius to function. And just because people don't like to let international bodies tell them what to do doesn't mean they don't participate. Just look at the UN Security Council. The US, Russia, and China are all in a war to see who gets the most vetoes of otherwise unanimous options.
It might not be a particularly functional or potent body but it could be a fun little arena to show off and develop the complicated inter-Sirius politics of the day.