One thing I fear is that eventually we'll reach a point where a dictatorship will establish itself and be so cruel and effective that it'll represent a permanent power which will dictate until it's own will to govern expires. North Korea seems like a close enough approximation but with the weapons and technology of the modern world it doesn't take that much creativity for a psychopath to imagine a world where that can occur.
Perhaps it's time I re-read Cryptonomicon.