It's pretty simple:
Terran Republic: NC and VS = Traitors to the Republic. Crucify them!
New Conglomerate: TR and VS = Enslavers of Humanity. Kill it with fire!
Vanu Sovereignty: TR and NC = Dangerous juveniles who have guns. Zap everyone who's not mature enough to know that wearing purple is awesome!
Of course the VS seem a little out of place. The TR and NC are still fighting over petty ideas like "Unity!" and "Freedom!" which are thousands of years out of date. The VS are fighting to protect humanities future transcendence.