Thoughtful and brilliant insights into the very nature of war—from the ancient Greeks to modern times—from the world's foremost expert historian. War—its imprint in our lives and our memories—is all around us, from the metaphors we use to the names on our maps. As books, movies, and television series show, we are drawn to the history and depiction of war. Yet we nevertheless like to think of war as an aberration, as the breakdown of the normal state of peace. This is comforting but wrong. War is woven into the fabric of human civilization. In this sweeping new book, international bestselling author and historian Margaret MacMillan analyzes the tangled history of war and society and our complicated feelings towards it and towards those who fight. It explores the ways in which changes in society have affected the nature of war and how in turn wars have changed the societies that fight them, including the ways in which women have been both participants in and the objects of war. MacMillan's new book contains many revelations, such as war has often been good for science and innovation and in the 20th century it did much for the position of women in many societies. But throughout, it forces the reader to reflect on the ways in which war is so intertwined with society, and the myriad reasons we fight.