Reality:
If you managed to create this global government, in five years these 6000 people would have offices in Belgium. They would become part of the system, same as happens everywhere governments get enough power. We change parties in the U.S., the only thing that really changes is the numbers in the lobbyist rolodexes.
All of this, of course, is accepting Rothkopf's premise at face value. I haven't read his book, but I've seen plenty of similar-sounding "Illuminati-type" theories about the Secret Rulers of the World.
Some people see it differently.