War’s fundamental nature is largely enduring, but it is not immutable. The essential elements are always present, but can and will be altered by ongoing social and technological changes presented in the emerging Age of Autonomous Systems. The accelerating introduction of cyber weapons, robots, and artificial intelligence will be major sources of change in how war is conducted. The impact in the conduct of war will influence the interactions of policy, populations, and their military forces in ways we are only beginning to consider. Advances in artificial intelligence will introduce a new source of rationalism in war that alters the existing relationship in Clausewitz’s trinity. Decades from now, this new source of rational calculation and genius may well deserve recognition as a new element in war.