Marc:

Lots of people actually know how to create borders---but they must be definitive, accepted, and defensible if they are to survive without conflict.

Demographics, culture and economics often run over poorly defined borders that are obstructed from natural change (or correction).

This idea of borders cannot change is what stands against the march of history: read USA, Germany, Pakistan, etc...

History has been, and will continue to be written by conflicts surrounding improperly set, or conflicting borders and national/sub-national governance structures.

Aversion to change is a characteristic of empires, often creating the history of conflicts.