Before I explore the main subject of this essay, I wanted to relate a tale about Alexander the Great’s leadership acumen. The historian Arrian relates an event that he believes best distills Alexander’s genius for command. It can be found in VI.26 of his History of Alexander. When Alexander and his army were passing through the Gedrosian desert (a part of what is now Baluchistan), they ran low on water and began to be tormented by extreme thirst. Water was almost nowhere to be found, and it would be some time before they could reach a reliable aquifer.