Divides the powers into Branches - Separation of powers
Divides the power between central and state govern. - Federalism
Each Branch of govern. - Checks and Balances
I think it becomes difficult because they all wanted to have more advantages than anyone else, that became too much for the country that they defeated. The Potsdam Conference became difficult because they have problems on the things that they should do with Germany that they want to completely disarm the country.
Mesopotamia was the location for an empire founded by "Sargon"--known as "Sargon of Akkad," since this was a highly advantageous place to build an empire due to the fertile soil and trade possibilities.
Darius divided the Persian Empire into serval provinces to make it easier to govern.
