Yvonne Chiu: Conspiring with the Enemy: The Ethic of Cooperation in Warfare. (New York: Columbia University Press, 2019. Pp. xvi, 344.)

Clausewitz made the intuitively appealing claim that wars tend to “absoluteness,” and that all limitations imposed by law and morality are in theory alien to it. Clausewitz of course knew that there are in practice many limitations to how wars are fought, but he saw them as contingent to what war is. Since then, however, historians such as John Lynn (Battle: A History of Combat and Culture [Westview Press, 2003]), John Keegan (A History of Warfare ([Random House,1993]) and Victor Davis Hanson (The Western Way of War [Oxford University Press, 1989]) have taught us to see things differently: war is a cultural phenomenon, and the limitations that rituals and taboos impose are essential to what war is. With Conspiring with the Enemy, her intelligent and erudite book on cooperation in war, Yvonne Chiu builds on that work by showing the wide variety of forms cooperation in war can take—something that, Chiu claims, we tend to overlook and take for granted at the same time.