Ray Kerkhove's How They Fought brings to light a big question: how do we measure warfare? War, as a concept, is difficult to define. A complex idea such as 'war' has multiple pasts, and it is the role of a legal historian such as me to show the paths taken to our modern understandings - fashionably called 'intellectual genecology'. War, being a fundamentally political concept, must be seen within its historical construct. It is due to its historical basis that its employment successfully constitutes a generative metaphor.