Good point. During Sun Zi’s time, war was not considered a productive activity. It took men away from the fields. It’s industrialization that makes protracted war possible, and unprecedented economic debt (theft from other parts of the world and future generations). Our environment is paying the price. In the long run, Sun Zi is right in that protracted war is unsustainable. Stay tuned for the incipient economic and climate collapse. We are only at the start of that.