The only reason Egypt has even existed from ancient times until today is because of the Nile River, which provides a thin, richly fertile stretch of green through the desert.

The country now fears a potential threat to that lifeline as Ethiopia is finalizing construction of the Grand Ethiopian Renaissance Dam.

It's Ethiopia's first major dam on the Blue Nile — one of the Nile's two main tributaries — and the project includes a giant reservoir that will power the largest hydroelectric dam in Africa.

The Nile provides over 90 percent of Egypt's water supply.

Egypt fears Ethiopia's dam will cut into its water supply, destroying parts of its precious farmland, hampering its large desert reclamation projects and squeezing its bourgeoning population of 93 million people already facing water shortages.