This week's episode of Horns of a Dilemma is a must-listen for anyone who knows that microchips are a national security issue, but perhaps doesn't really understand just why chips are so strategically important. It is equally enlightening for those who have been closely following the security issues around microchips and are eager to know more. Professor Chris Miller of the Fletcher School at Tufts University gives a detailed, accessible overview of what microchips are, how they are used, where and how they are made, and the implications of the microchip supply chain for national security.  His talk is based on his book, Chip Wars: The Fight for the World's Most Critical Technology. Miller spoke in early November at the University of Texas, Austin.