How has a persistent state of water scarcity influenced conflict and insecurity in Yemen?

The civil war in Yemen has old origins, but the recent violence can be traced back to the Arab Spring of 2011, and protests in Yemen over unemployment, corruption, and general dissatisfaction with President Ali Abdullah Saleh. On the surface, the civil war seems to be a politically-motivated competition for power among many actors with varying motives. However, underneath the obvious political and societal tensions, there lies a more basic tension: water.