Book excerpt: 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 century, new technologies continue to push warfare in unexpected directions, while warfare stimulates stunning new technological advances. Yet even now, the newest and best technology cannot guarantee victory. Brimming with dramatic narratives of battles and deep insights into military psychology, this book shows that although military technologies keep changing at great speed, the principles and patterns behind them abide.