The U.S.-Mexican border – the border fence runs through the bottom of the photo – spans some 2,000 miles. Two thousand miles is just as long as it sounds. It is twice the length of the Europe-Soviet Cold War border. Securing the U.S.-Mexican border is simply impossible, not only for the Mexicans, but also for the United States. If the United States relocated all of its military forces to the border, it would only be enough for one solider about every 50 feet. Between the region’s desolation and remoteness, it almost seems it was designed expressly for smuggling, whether that be for smuggling people or narcotics. The open, unsecurable nature of that border is at the core of the greatest geopolitical challenge the United States faces. For more information, see Chapter 13 of The Accidental Superpower