There is no institution in America as big as the Department of Defence, and the Pentagon is a vast and powerful presence. Yet to most citizens it is mysterious - especially now, as the president levels accusations against his intelligence agencies. The need for this book, which demystifies the Pentagon and lays bare the inner workings of the Department of Defence, is more urgent than ever. 25th U.S. Secretary of Defence, Ash Carter, provides clear insight and sheds light on exactly what is happening inside one of the USA's most iconic buildings and most closely guarded institutions.