Although logistics, the art of supplying and moving armed forces, do not possess the drama of battle, they underlay strategy and determine victory or defeat. As the old axiom goes, "Amateurs study tactics; professionals study logistics."
Navies evolved mechanisms of supply before armies did because sailors could not live off the land as soldiers could. Whatever a vessel and its crew required during its voyage, or at least until its next port of call, had to be stowed aboard from the start (see
Feeding Armed Forces). Thus, navies developed arsenals and warehouses to take care of all of their needs (see
Arsenals). However, although navies existed in a more demanding logistical environment than did armies, they also enjoyed certain advantages. First, ships provided an excellent means to carry the very supplies their crews required, since water transport has always been the best means to move bulk cargoes. Second, a major logistical concern for armies—horses—was irrelevant to navies.
Armies too tried to exploit water transport when possible, but ultimately they had to rely upon overland communications. The simplest supply method required that men on foot carry their own foodstuffs, as did the
Zulu of southern Africa, but since a man can lug only about sixty or seventy pounds at best, this method had inherent limitations. Pack and draft animals increased an army's carrying capacity but added the need for fodder to the army's already great need for food. Armies lessened some supply difficulties by living off the country, and until the twentieth century, this was common practice. In particular, the bulk and weight of fodder for animals prohibited its overland shipment in most circumstances; instead, it had to be gathered in the field during the spring and summer. Horse peoples of the steppe and central Asia raided widely on their grasslands but suffered when they moved into forested or arid lands. It was probably more the lack of sufficient fodder that stopped
Attila than the Roman and German forces he encountered. In the early modern era, European armies dependent on horses for transport could campaign only while grass was in the fields, so as fall set in and fodder withered, armies retired to winter quarters.
Feeding men by living off the country was more risky than collecting fodder in the field. Ancient and medieval armies certainly understood the advantages of living off the enemy's resources, of making war feed war. Early modern European armies, however, discovered that as forces grew larger, living off the country could destroy discipline—that men sent out to forage often marauded and deserted. The excesses of foraging soldiers became legendary during the
Thirty Years' War (1618-1648). By the late seventeenth century, armies undertook to supply their soldiers with food from regular magazines and field ovens, but this traded one problem for another, since maneuver became more constrained by supply lines. The armies of the
French Revolution and
Napoleon dispensed with umbilical cords of supply to some extent by again resorting to foraging for food.
The coming of steam-driven transport speeded the movement of supplies. Yet naval logistics became increasingly complicated as steam replaced sails, because ships now frequently called at port to refill their bunkers, and imperial powers required coaling stations prepared around the globe to ensure their mobility. Although the transition to oil-fired boilers in the early twentieth century simplified refueling at sea, the need for supply bases to feed engines as well as crews persisted.
Although ocean-going vessels accelerated long-range transport, river steamers and railroads could rarely bring supplies right up to an army on the move. Moreover, railroads were notoriously fragile supply lines, since rails and bridges made tempting targets for enemy raiders and could easily be destroyed as an army retreated. Thus, horses remained indispensable to link river ports and railheads with armies, and horse transportation still limited the speed of advance. During the
Franco-Prussian War, and even in
World War I, the advancing Germans outstripped railroads and wagons and thus relied very much on what they could take from French fields.
The internal combustion engine transformed the logistical environment of warfare on land more radically than steam power did. Trucks proved essential in World War I, which was probably the first war in which the main forces depended entirely upon supplies shipped in from the rear. Trucks, perhaps even more than tanks, made the mobile warfare of
World War II possible. But although trucks opened up new possibilities they were not without limitations. When
Erwin Rommel ground to a halt at
El Alamein, it had a great deal to do with the fact that he had exceeded the maximum range at which his trucks could ferry supplies to the Afrika Korps.
The emphasis on motorized transport created a whole new logistical need for armies: petroleum fuel and lubricants. For U.S. land and air forces in Europe during World War II, this amounted to 37 percent by weight of supplies shipped, making it the single greatest burden on the supply system. And modern armies also have increased needs for ammunition. Until the mid-nineteenth century, provided an army did not undertake a siege, it could probably conduct a campaign with the powder and shot it carried with it at the start. In contrast, modern weapons shoot off vast quantities of ammunition, making resupply a major logistical task.
Since World War II, air transport has helped to move troops and matériel. Göring's failed promise to supply German forces at
Stalingrad by air in 1942-1943 demonstrated the inability of airplanes to keep up a steady flow of supplies before 1945. Today, although the great mass of war matériel must still move by water or overland, huge cargo planes can rapidly deploy the supply necessary for small forces or ship in selected key cargoes for larger forces; they did both during the
Gulf War. Still, aircraft have proved more valuable in moving troops than matériel, because the physics of air transport makes the carrying of bulk cargo difficult and expensive.
John A. Lynn, Feeding Mars (1993); Martin van Creveld, Supplying War (1977).