The author traces the long sequence of political, linguistic, and social developments across Europe that culminated in the great continental war, beginning with ancient invasions and the rise of centralized states. Chapters explain how kingdoms and empires grew from earlier chiefdoms, how borders were often imposed without regard to language and ethnicity, and how alliances, imperial ambition, and militarism made large-scale conflict likely. Using maps and clear exposition, the book outlines alternative national arrangements, surveys diplomatic and naval aspects, assesses the human and material cost, and proposes educational and institutional reforms aimed at preventing future wars.