Reasons for Decline
The Mesopotamian civilization declined because of two main reasons. The first is that the Mesopotamian life style was badly destroyed by war. The different city-states were fighting for control of each others lands and would wage all out conflicts among each other to gain territory. They mostly fought for farmland and irrigation waters. The second reason for the decline of the Mesopotamian civilization was due to the irrigation techniques they used. The same techniques that made farming possible also prevented farming from occurring in later dates. After irrigation water sits on the land, over time, the water leaves behind mineral salt which will eventually erode the farming land.
The Standard of Ur War