An army marches on its stomach – Napoleon Bonaparte
While we have no real idea how much insight Xenophon possessed when he joined the invasion of Persia, the Anabasis is written by a professional with a profound appreciation of the issues of logistics (as is the Agesilaus). From beginning to end, the Anabasis is replete with not just the story of the Persian expedition, but how the Greek forces managed to maintain themselves in supply, from the time of their entry into Persia, until their retreat is complete. Xenophon understands that other professionals will be interested in this as much as in anything else that he relates. It is likely that Alexander read these logistical details with great attention. For instance, if you re-read the Anabasis from the perspective of a logistician, you will find that it serves as a nearly complete narrative of the logistics of the Persian expedition. In most instances, you are far more certain of how the Greeks remained in supply than of what happened to them in battle. If you compare it to other histories you have read, you may well find that there is, well, no comparison.
“Amateurs talk about strategy, professionals talk about logistics.” – US Army dictum
Logistic considerations are a principal determinant of the route Cyrus chooses for his army as he advances into Persia to engage his brother’s army. While he hopes to delay the detection of his advance until his army is in Babylon, his choices are limited to those that can keep his army in supply. Logistics also constrains the route of retreat selected by the Greeks under Xenophon. What constitutes a suitable route for egress? The land must be rich enough to provide for the Greeks; whether they purchase their supplies at market or loot the land as its inhabitants flee before them. It must be passable to the wagons and animals of the baggage train that accompany the Greek army. As the Greeks seek to avoid war with every Satrapy they traverse, they negotiate the purchase of supplies at market, or limit their looting to their minimum needs. Others with more specialized expertise might have more to say about this, but to this reader this policy seems like a prescient and radical departure from the custom of war for most of the past three thousand years. For most of history, advancing armies stripped the land of food, fodder, and loot; to the occupants, the only thing that distinguished ‘friendly’ forces from their foes was the uniform of the troops wreaking destruction. It is likely that their reputation preceded the Greeks, and that several of the Satraps conducted only token operations against the Greeks as they passed through; enough to fulfill their obligation to their king, not so much that they got a large number of their soldiers killed. Similarly, Xenophon understood that the Greek army could not endure pitched battles with the army of every Satrapy they crossed; avoiding battle whenever possible was synonymous with avoiding destruction. Ironically, it also seems inevitable that the Greeks paid for their supplies with the loot from Satraps that had chosen to oppose their retreat. If all of the Satrapies had opened their markets to the Greeks, they would have run out of money long before they got back to Greek territory.
As long as there have been armies, there have been camp followers. Camp followers enable infantry to deploy with the maximum combination of fighting power and mobility. Camp followers enable infantry to patrol and to fight, and an army to move with more speed and safety that it would otherwise. Soldiers marching into battle will carry whatever equipment they believe will increase their chances of surviving and prevailing, and as little of everything else that they can. Given a choice between carrying the bedding, the squads cooking utensils, or their tent, and increased mobility, infantry have always chosen in favor of more mobility. At times in history, some armies have used their own soldiers to operate and guard their camps, but this has been the exception, not the rule. Why leave perfectly good infantry behind to run and guard the camp, when you could use them to bolster your ranks? Thus, in history, most camps have been run by camp followers, who, by virtue of their physical ability, age, ethnicity, lack of skill-at-arms and training, or gender, were less useful or completely useless for combat.
At one point, Xenophon exhorts his army to abandon everything that might slow their movement, an ancient version of modern attempts to reduce the tooth-to-tail ratio. No success. The Anabasis makes the vital role of camp followers clear: in spite of a potentially existential benefit to leaving them behind, the Greek army finds itself unable to continue reduce the tail by much. Modern economists would be completely unsurprised that an ancient army would benefit from this kind of specialization, matching expertise with role in a larger organization; but at the time, it was likely difficult to understand or articulate, at least until after you had worked through it and figured out how poorly it would work out. History is replete with account of battles in which troops break away from their battlefield deployments when their baggage train or encampment is threatened by enemy forces. Amateurs attribute this concern to base greed on the part of the masses of troops; professionals understand that an army that has lost its baggage train has lost a substantial amount of its power. The fate of an army that has lost its camp followers is not much different than the fate of camp followers who have last their army. Xenophon understood this, and throughout the retreat deploys his army in such a way to not only insure the safety of his baggage train, but also make certain that all of the troops of his army understand this as well. At points, his deployments and evolutions risk his army to protect his baggage train.
Xenophon’s narrative emphasizes logistics, the mark of a true professional. Xenophon understood that logistics considerations shape military operations. He also understood that the lower the price he paid in blood to fulfill his logistic requirements, the greater the chances were that he would see Greece again. He understood the critical role that his camp followers played in producing the military power that he was controlling. Aristotle tutored Alexander, and many experts believe that Alexander studied Xenophon’s work with professional interest. Alexander’s subsequent campaign in Persia was either shaped by the same forces that Xenophon describes, or by the narrative that he read.