Logistics is the science of providing and maintaining men, equipment, and supplies for military operations.
Modern armies armed with complex weapons and equipment require tremendous logistical effort to put them into battle and keep them there. For example, almost half of the total strength of the United States Army in World War II had to provide logistic support for the other half that came in direct contact with the enemy. One out of 4 men in a combat division performed duties related to logistics, such as supply and administration.
The extraordinary task of supplying an army can be imagined by comparing the amounts of artillery ammunition fired in World War I and in the American Civil War. During one average month of World War I, the British and French armies fired more than twice as much artillery ammunition as did the Union army during the entire four years of the Civil War.
Supply forms only one part of the task of logistics. Military forces must be moved from place to place. They must have lodging. Food must be prepared, and the sick and wounded must be cared for. Records on the fighting forces must be kept.
On land and in the air, chemical, engineer, medical, ordnance, quartermaster, signal, and transportation units provide logistic support for combat units. Service forces at sea composed of cargo ships, hospital ships, icebreakers, mine layers, oilers, repair ships, transports, and tugs provide this support to the warships of the
fighting fleets.
