As much as it may sound like I have a vested interest in Whitemarch, the very reason I live there is because it is a neutral state. I don't work FOR the Regent, I merely assist her when she requests me. I've also done a great deal of work in Nilhasse. I'm a doctor; I go where I'm needed. As far as the coffers being dry, that's only monetarily; both Etrugia and Nilhasse pay tribute in the form of dry goods to Whitemarch for taking on the refugees. Trade is thriving because of the ever-increasing cross section of peoples, and so humans and Mamono both are moving in all the time because it's safe and secure and with expansion, jobs are guaranteed. As far as the Golems go, the Elves of Auturesse are the primary source of magic material, and this is their tribute for living in the State's boundaries. Likewise, the Dwarves contribute enormously with their metallurgy. (Incidentally, Auturesse is where I was raised.)
I wear the red robes of neutrality; I don't take sides. (Well, not really robes, but you get the idea.) My oath forbids it. If you want to discuss trade agreements, you'll have to go through the Regent.