The war instinct is part of human nature, but the means to fight war depend on technology. Alex Roland traces the co-evolution of technology and warfare from the Stone Age to the age of cyberwar, describing the inventions that changed the direction of warfare throughout history: from fortified walls, the chariot, battleships, and the gunpowder revolution to bombers, rockets, improvised explosive devices (IEDs), and nuclear weapons. In the twenty-first...