Sanger has done an excellent job of reporting, and now accumulating, accounts of cyberwarfare for many years now. History has shown that generals and presidents or rulers the world over have always prepared for the previous war, not the one that confronts them. Today’s war is being fought remotely through networks. Sanger does a good job of explaining how devastating an all-out attack could be. The United States is more vulnerable than any other nation because we are more connected than any other. Just consider what life would be like permanently without electricity or your local water system. Gas stations will have no gas or no way to pump what they have, so even generators won’t work long. The book is not written with an alarmist aim, but it is sobering. It can seem repetitive, but it is informative and readable.