What's wrong with a world government, incidentally? We started out as bickering tribes, and over time those coalesced into nations, which are basically just big tribes. Why not go the next step and have all of us humans be part of the same tribe? The nice thing about that is that tribes very rarely war against themselves; all one tribe, no more wars. It seemed to work okay for the folks in the Star Trek universe!

I figure we'll eventually grow up from the tribal view of the world (nations vs. other nations). The human race could accomplish much more if so much of its energy wasn't spent on factions fighting factions. Of course, I could be totally wrong and we'll just maintain the status quo and keep killing ourselves, and eventually wipe ourselves out.