Egypt, the most populous country in the Arab world, is facing a crisis: a growing shortage of food and water. How do you feed a population of 113 million people – estimated to grow to 160 million over the next 25 years – when even water is running short? The Nile, Egypt’s lifeline, is under stress. The government is drilling deep into the Sahara to tap underground aquifers and urging families to have fewer children. But are these measures enough? Edouard Dropsy and Mathilde Delvigne report.