What we see in places like Syria may ultimately spread to the whole world.
IMO World War III will include civil wars, often with more than two factions, within many existing states concurrent with international conflicts.
So there will be alliances and hostilities both within and across national boundaries. Both alliances and hostilities will be based on a wide variety of factors from geography to class to religion.
As this goes on, perhaps for hundreds of years, there may be a global resorting of populations according to various affinities and identities–and in the end the geopolitical map may be completely redrawn.
Hopefully the new world order won’t be a global corporatocracy, but it very well might be.