A seasoned peacebuilder and acclaimed expert on violence explains the five reasons why conflict (rarely) blooms into war and how to avoid that deadly result, Why We Fight draws on decades of economics, political science, psychology, and real-world interventions to lay out the root causes and remedies for war, showing that violence is not the norm, that there are only five reasons why conflict wins over compromise, and how peacemakers turn the tides through tinkering, not transformation. From warring states to street gangs, ethnic groups and religious sects to political factions, there are common dynamics to heed and lessons to learn. Along the way, through Christopher Blattman's time studying Medellin, Chicago, Sudan, Britain, and more, we learn from vainglorious monarchs, dictators, mobs, pilots, football hooligans, ancient peoples, and fanatics. What of remedies that shift incentives away from violence and get parties book to dealmaking? Societies are surprisingly good at interrupting and ending violence when they want to-even do it. Realistic and optimistic, this is a book that lends new meaning to the adage "Give peace a chain."