Why Wars Happen is a groundbreaking inquiry into the crucial yet surprisingly understudied question of why wars occur. Jeremy Black, one of Britain's foremost military historians, presents an interdisciplinary study that draws on subjects such as history, political science, and international relations and marshals a vast range of material with global examples spanning from the fifteenth century to today.

Black examines several major modern wars in their historical contexts, taking into account cultural differences and various conflict theories. He analyzes the three main types of war—between cultures, within cultures, and civil—and explores the problems of defining war. Black's investigation inspires fascinating questions such as: Do wars reflect the bellicosity in societies and states, or do they largely arise as a result of a diplomatic breakdown? How closely is war linked to changes in the nature of warfare, the international system, or the internal character of states? Black also considers contemporary situations and evaluates the possible course of future wars. Offering a valuable and thought-provoking analysis on the causes of war and conflicts, Why Wars Happen will interest historians and readers of military history alike.