How do you feed 10 billion people? It is not just a humanitarian question, but a vital U.S. national security imperative. A recent U.N. report projects a 46 percent population increase by 2100. Africa, home to more than a quarter of the world's undernourished people and more than 20 violent conflicts in the past half century, is predicted to more than double its population. We must not only consider how to feed all of these people — but what it means if we can't. Food commodity prices are at record highs, leading to instability in already volatile regions. The Pentagon's……