Throughout history two distinct styles of warfare can be identified. The most ancient is the war of attrition: the enemy surrenders because you have killed so many of its men. A general fighting a war of attrition will calculate ways to overwhelm the other side with larger numbers, or with the battle formation that will do the most damage, or with superior military technology. In any event, victory depends on wearing down the other side in battle. Even with today’s extraordinary technology, attrition warfare is remarkably unsophisticated, playing into humanity’s most violent instincts.