Oil is the Middle East's glamor product, sought after by the entire world and bringing the region wealth beyond the dreams of avarice. But water is the mundane resource that matters even more to locals for, without it, they face the horrible choice of leaving their homes or perishing within them.

That choice may sound hyperbolic, but the threat is real. Egypt stands out as having the largest population at risk and being the country, other than Iraq and Yemen, with the most existential hydrologic problem.

As every schoolchild learns, Egypt is the gift of the Nile and the Nile is by far the globe's longest river. Less well known is that most of the Nile's volume, 90 percent, comes from the highlands of Ethiopia and that the river passes through 11 countries. For uncounted eons, its water flowed to Egypt in uncounted quantities.