I must say, traquet, that's a pretty heavy topic for a first post. Lemme see if I can put in my two cents on this. I must warn you, two cents nowadays ain't worth that much.
The Princess of Wands represents Asia, the cradle of civilization. Wands represent the Fire element, which is also a symbol of civilization, as in the tale of Prometheus giving the gift of fire to Mankind.
The Princess of Cups represents the Pacific Ocean. Cups represent the Water element. No idea what role the Pacific Ocean has played in world history, so I'll leave it up to others to fill in this blank.
The Princess of Swords represents the Americas. Swords represent the Air element, which is also a symbol for thought and mental activity. Much of the progress that we enjoy today can be traced back to revolutionary ideas that emanated from the Americas. Swords also represent violence, and no one can deny that the Americas have been responsible for much of the conflict that the world has seen over the past century or so.
Finally, the Princess of Disks represents Europe and Africa. Disks represent the Earth element. As we move from a money-based society to one that is resource based, resource-rich Europe and Africa will become the strongest regions in the world and global leadership will eventually transfer to this region from the Americas, which is close to bankruptcy.