How is the water within the Nile politically important?
Water is the world's most precious natural resource. No living creature, and certainly not humans, can live without it. Supplies of fresh water are in danger globally of disappearing. While the importance to the global economy of oil is widely acknowledged and discussed, the threat to the world's fresh water supplies receives much less attention. As arid regions of the planet begin to compete for increasingly scarce supplies of water, the potential for wars to break out over access to or control of such supplies will continue to grow.
The Nile is the longest river in the world, and between the main river and its various tributaries it touches many countries in northeastern Africa. The tens of millions of people in poverty-stricken and strife-torn countries like Egypt, Sudan, South Sudan, the Democratic Republic of Congo, Ethiopia, Eritrea and others are all dependent to one degree or another upon the Nile for their fresh water. Egypt, with its 82 million people, is deeply tied to the Nile, economically, culturally, and politically.
With so many countries touched by the Nile, any changes, man-made or natural, that affect it also affect millions of people. When Egyptian leader Gamal Abdul Nasser contracted with the Soviet Union to construct a large dam, known as the Aswan High Dam, to control the annual flooding of the Nile, countries along the Mediterranean Sea were concerned. Because the Nile flows northward toward the Mediterranean, the so-called upriver countries were not affected. The Mediterranean, however, was adversely affected, as the Nile is a major source of fresh water into the salt water sea. The decrease in the flow of fresh water altered the composition of the Mediterranean, which in turn adversely affected fishing in the sea.
To the extent that political control of the Nile could be attained, such control would give its holder tremendous influence over northeastern Africa. In addition to the countries listed above, Tanzania, Burundi, Rwanda, Uganda and Kenya would all be held hostage to some degree to the demands of whatever government controlled the Nile. That is why any attempt by countries close to the source of the Nile (possibly Lake Victoria) to take actions that could affect the river would raise alarm bells not just in Africa, but across the entire world.