This is the first of a two-part series about the twentieth century. The book attempts to explain the origins of World War I, which is vital to understand what caused World War II. Except for the naval battle at Jutland, the book does not attempt to give a detailed explanation of the various battles of the First World War. It simply discusses strategy and weapons. Some of the battles of World War II are covered in much greater detail. The longest segment on the Battle of Midway offers a highly detailed and thoroughly researched version of the conflict and the outcome.