But because it's such a precious limited resource, the Nile has also long been a cause of conflict. 700 years ago, Ethiopia threatened to divert the Nile because what it said was Muslim prosecution of Christians down river in Egypt. Now the two countries once again locked in a bitter dispute over ownership and use of the river. To understand what's happening, I need to take to the air.
-When's your plane take off?
-It will take off for the moment actually. I got it. Thank you very much.
-Here beneath us is the Blue Nile.