Military logistics
Encyclopedia
Military
logistics
is the discipline of planning and carrying out the movement and maintenance of military forces. In its most comprehensive sense, it is those aspects or military operations that deal with:
adjective logistikos meaning "skilled in calculating". The first administrative
use of the word was in Roman
and Byzantine
times when there was a military administrative official with the title Logista. At that time, the word apparently implied a skill involved in mathematical computations.
Research indicates that its first use in relation to an organized military administrative science was by the Swiss writer, Antoine-Henri Jomini
, who, in 1838, devised a theory of war
on the trinity of strategy
, ground tactics
, and logistics
. The French still use the words logistique and loger with the meaning "to quarter".
The military activity known as logistics probably is as old as war itself. In the early history
of man when the first wars were fought, each man had to find his own food, stones, and knotted clubs. Each warrior
was responsible for foraging for his own food and firewood.
Not until later, when fighters joined as groups and fighting groups became larger, was there any basis for designating certain men to specialize in providing food
and weapons to the combatants. The men who provided support to the fighters constituted the first logistics organization.
By the seventeenth century, the French were using a magazine
system to keep a network of frontier towns supplied for sieges and to provide for campaign
s beyond their borders. The American Civil War
saw the introduction of railways for transport of personnel, supplies and heavy field pieces.
Until the Napoleonic wars
, the military supply was ensured by looting, requisition
or private companies. In 1807, Napoleon created the first Train
regiments, entirely dedicated to the supply and the transport of the equipment.
During the Seven Weeks War
, railways enabled the swift mobilization of the Prussian Army, but the problem of moving supplies from the end of rail lines to units at the front resulted in nearly 18,000 tons trapped on trains unable to be unloaded to ground transport. The Prussian use of railways during the Franco-Prussian War
is often cited as a prime example of logistic modernizations, but the advantages of maneuver were often gained by abandoning supply lines that became hopelessly congested with rear-area traffic.
During World War I
, unrestricted submarine warfare had a significant impact on the ability of Britain's allies to keep shipping lanes open, while the great size of the German Army proved too much for its railways to support except while immobilized in trench warfare.
", must address highly uncertain conditions. While perfect forecasts are rarely possible (this is also true in most sciences) forecasts models can reduce uncertainty about what supplies or services will be needed, where and when they will be needed, or the best way to provide them.
Ultimately, responsible officials must make judgments on these matters, sometimes using intuition and scientifically weighing alternatives as the situation requires and permits. Their judgments must be based not only upon professional knowledge of the numerous aspects of logistics itself but also upon an understanding of the interplay of closely related military considerations such as strategy
, tactics
, intelligence
, training
, personnel, and finance
.
However, case studies have shown that more quantitative, statistical analysis are often a significant improvement on human judgment. One such recent example is the use of Applied Information Economics
by the Office of Naval Research and the Marine Corps for forecasting bulk fuel requirements for the battlefield.
In major military conflicts, logistics matters are often crucial in deciding the overall outcome of wars. For instance, tonnage war
- the bulk sinking of cargo ships - was a crucial factor in World War II
.
The successful Allied anti-submarine campaign and the failure of the German Navy to sink enough cargo in the Battle of the Atlantic allowed Britain to stay in the war and establish the second front against the Nazis; by contrast, the successful U.S. submarine campaign
against Japanese maritime shipping across Asian waters effectively crippled its economy and its military production capabilities.
More generally, protecting one's own supply lines and attacking those of an enemy is a fundamental military strategy; an example of this as a purely logistical campaign for the military means of implementing strategic policy was the Berlin Airlift.
Military logistics has pioneered a number of techniques that have since become widely deployed in the commercial world. Operations research
grew out of WWII military logistics efforts. Likewise, military logistics borrows from methods first introduced to the commercial world.
The Kargil Conflict in 1999 between India and Pakistan also referred to as Operation Vijay (Victory in Hindi) is one of the most recent examples of high altitude warfare in mountainous terrain that posed significant logistical problems for the combating sides. The Stallion which forms the bulk of the Indian Army’s logistical vehicles proved its reliability and serviceability with 95% operational availability during the operation.
is a key factor in military affairs. The shorter the distance, the greater the ease with which force can be brought to bear upon an opponent. This is because it is easier to undertake the supply of logistics to a force on the ground as well as engage in bombardment
. The importance of distance is demonstrated by the Loss of Strength Gradient
devised by Kenneth Boulding. This shows the advantage of supply that is forward based.
Supply chain management in military logistics often deals with a number of variables in predicting cost, deterioration, consumption, and future demand. The US Military's categorical supply classification was developed in such a way that categories of supply with similar consumption variables are grouped together for planning purposes. For instance peacetime consumption of ammunition and fuel will be considerably less than wartime consumption of these items, whereas other classes of supply such as subsistence and clothing have a relatively consistent consumption rate regardless of war or peace. Troops will always require uniform and food. More troops will require equally more uniforms and food.
In the table above, each class of supply has a consumer. Some classes of supply have a linear demand relationship - as more troops are added more supply items are needed - as more equipment is used more fuel and ammo is consumed. Other classes of supply must consider a third variable besides usage and quantity: time. As equipment ages more and more repair parts are needed over time, even when usage and quantity stays consistent. By recording and analyzing these trends over time and applying to future scenarios, the US Military can accurately supply troops with the items necessary at the precise moment they are needed. History has shown that good logistical planning creates a lean and efficient fighting force. Lack thereof can lead to a clunky, slow, and ill-equipped force with too much or too little supply.
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...
logistics
Logistics
Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...
is the discipline of planning and carrying out the movement and maintenance of military forces. In its most comprehensive sense, it is those aspects or military operations that deal with:
- Design, development, acquisitionMilitary acquisitionMilitary acquisition is the bureaucratic management and procurement process dealing with a nation's investments in the technologies, programs, and product support necessary to achieve its national security strategy and support its armed forces...
, storage, distribution, maintenance, evacuation, and disposition of materielMaterielMateriel is a term used in English to refer to the equipment and supplies in military and commercial supply chain management....
. - Transport of personnel.
- Acquisition or construction, maintenance, operation, and disposition of facilities.
- Acquisition or furnishing of services.
- Medical and health service support.
Origins
The word "logistics" is derived from the GreekGreek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
adjective logistikos meaning "skilled in calculating". The first administrative
Public administration
Public Administration houses the implementation of government policy and an academic discipline that studies this implementation and that prepares civil servants for this work. As a "field of inquiry with a diverse scope" its "fundamental goal.....
use of the word was in Roman
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
and Byzantine
Byzantine Empire
The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...
times when there was a military administrative official with the title Logista. At that time, the word apparently implied a skill involved in mathematical computations.
Research indicates that its first use in relation to an organized military administrative science was by the Swiss writer, Antoine-Henri Jomini
Antoine-Henri Jomini
Antoine-Henri, baron Jomini was a general in the French and later in the Russian service, and one of the most celebrated writers on the Napoleonic art of war...
, who, in 1838, devised a theory of war
War
War is a state of organized, armed, and often prolonged conflict carried on between states, nations, or other parties typified by extreme aggression, social disruption, and usually high mortality. War should be understood as an actual, intentional and widespread armed conflict between political...
on the trinity of strategy
Strategy
Strategy, a word of military origin, refers to a plan of action designed to achieve a particular goal. In military usage strategy is distinct from tactics, which are concerned with the conduct of an engagement, while strategy is concerned with how different engagements are linked...
, ground tactics
Military tactics
Military tactics, the science and art of organizing an army or an air force, are the techniques for using weapons or military units in combination for engaging and defeating an enemy in battle. Changes in philosophy and technology over time have been reflected in changes to military tactics. In...
, and logistics
Logistics
Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...
. The French still use the words logistique and loger with the meaning "to quarter".
The military activity known as logistics probably is as old as war itself. In the early history
History
History is the discovery, collection, organization, and presentation of information about past events. History can also mean the period of time after writing was invented. Scholars who write about history are called historians...
of man when the first wars were fought, each man had to find his own food, stones, and knotted clubs. Each warrior
Warrior
A warrior is a person skilled in combat or warfare, especially within the context of a tribal or clan-based society that recognizes a separate warrior class.-Warrior classes in tribal culture:...
was responsible for foraging for his own food and firewood.
Not until later, when fighters joined as groups and fighting groups became larger, was there any basis for designating certain men to specialize in providing food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
and weapons to the combatants. The men who provided support to the fighters constituted the first logistics organization.
By the seventeenth century, the French were using a magazine
Magazine (artillery)
Magazine is the name for an item or place within which ammunition is stored. It is taken from the Arabic word "makahazin" meaning "warehouse".-Ammunition storage areas:...
system to keep a network of frontier towns supplied for sieges and to provide for campaign
Military campaign
In the military sciences, the term military campaign applies to large scale, long duration, significant military strategy plan incorporating a series of inter-related military operations or battles forming a distinct part of a larger conflict often called a war...
s beyond their borders. The American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...
saw the introduction of railways for transport of personnel, supplies and heavy field pieces.
Until the Napoleonic wars
Napoleonic Wars
The Napoleonic Wars were a series of wars declared against Napoleon's French Empire by opposing coalitions that ran from 1803 to 1815. As a continuation of the wars sparked by the French Revolution of 1789, they revolutionised European armies and played out on an unprecedented scale, mainly due to...
, the military supply was ensured by looting, requisition
Requisition
A requisition is a request for something, especially a formal written request on a pre-printed form.An online requisition is an electronic document, which can be originated by the requester and then using the company workflow or hierarchy rules, can be submitted to the subsequent levels, until it...
or private companies. In 1807, Napoleon created the first Train
Train (military)
In military contexts a train can refer to logistic elements of a force or organisation. In this context the term train usually does not mean a railway train.Historically and for land forces, this usually referred to troops that are endowed with horses...
regiments, entirely dedicated to the supply and the transport of the equipment.
During the Seven Weeks War
Austro-Prussian War
The Austro-Prussian War was a war fought in 1866 between the German Confederation under the leadership of the Austrian Empire and its German allies on one side and the Kingdom of Prussia with its German allies and Italy on the...
, railways enabled the swift mobilization of the Prussian Army, but the problem of moving supplies from the end of rail lines to units at the front resulted in nearly 18,000 tons trapped on trains unable to be unloaded to ground transport. The Prussian use of railways during the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...
is often cited as a prime example of logistic modernizations, but the advantages of maneuver were often gained by abandoning supply lines that became hopelessly congested with rear-area traffic.
During World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, unrestricted submarine warfare had a significant impact on the ability of Britain's allies to keep shipping lanes open, while the great size of the German Army proved too much for its railways to support except while immobilized in trench warfare.
Modern developments
Logistics, occasionally referred to as "combat service supportCombat service support
Combat service support is a subset of military logistics. Combat service support is more limited in depth than logistics, as it primarily addresses those factors directly influencing combat operations.-United States Army:...
", must address highly uncertain conditions. While perfect forecasts are rarely possible (this is also true in most sciences) forecasts models can reduce uncertainty about what supplies or services will be needed, where and when they will be needed, or the best way to provide them.
Ultimately, responsible officials must make judgments on these matters, sometimes using intuition and scientifically weighing alternatives as the situation requires and permits. Their judgments must be based not only upon professional knowledge of the numerous aspects of logistics itself but also upon an understanding of the interplay of closely related military considerations such as strategy
Strategy
Strategy, a word of military origin, refers to a plan of action designed to achieve a particular goal. In military usage strategy is distinct from tactics, which are concerned with the conduct of an engagement, while strategy is concerned with how different engagements are linked...
, tactics
Military tactics
Military tactics, the science and art of organizing an army or an air force, are the techniques for using weapons or military units in combination for engaging and defeating an enemy in battle. Changes in philosophy and technology over time have been reflected in changes to military tactics. In...
, intelligence
Intelligence (information gathering)
Intelligence assessment is the development of forecasts of behaviour or recommended courses of action to the leadership of an organization, based on a wide range of available information sources both overt and covert. Assessments are developed in response to requirements declared by the leadership...
, training
Training
The term training refers to the acquisition of knowledge, skills, and competencies as a result of the teaching of vocational or practical skills and knowledge that relate to specific useful competencies. It forms the core of apprenticeships and provides the backbone of content at institutes of...
, personnel, and finance
Finance
"Finance" is often defined simply as the management of money or “funds” management Modern finance, however, is a family of business activity that includes the origination, marketing, and management of cash and money surrogates through a variety of capital accounts, instruments, and markets created...
.
However, case studies have shown that more quantitative, statistical analysis are often a significant improvement on human judgment. One such recent example is the use of Applied Information Economics
Applied information economics
Applied information economics is a decision analysis method developed by Douglas W. Hubbard and partially described in his book How to Measure Anything: Finding the Value of Intangibles in Business . AIE is a method for the practical application of several proven methods from decision theory and...
by the Office of Naval Research and the Marine Corps for forecasting bulk fuel requirements for the battlefield.
In major military conflicts, logistics matters are often crucial in deciding the overall outcome of wars. For instance, tonnage war
Tonnage war
A tonnage war is a military strategy aimed at merchant shipping. The premise is that an enemy has only a finite number of ships, and a finite capacity to build replacements for them. The concept was made famous by U-boat commander Karl Dönitz, who wrote: The shipping of the enemy powers is one...
- the bulk sinking of cargo ships - was a crucial factor in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
The successful Allied anti-submarine campaign and the failure of the German Navy to sink enough cargo in the Battle of the Atlantic allowed Britain to stay in the war and establish the second front against the Nazis; by contrast, the successful U.S. submarine campaign
Allied submarines in the Pacific War
Allied submarines were used extensively during the Pacific War and were a key contributor to the defeat of the Empire of Japan. During the war, submarines of the United States Navy were responsible for 55% of Japan's merchant marine losses; other Allied navies added to the toll. The war against...
against Japanese maritime shipping across Asian waters effectively crippled its economy and its military production capabilities.
More generally, protecting one's own supply lines and attacking those of an enemy is a fundamental military strategy; an example of this as a purely logistical campaign for the military means of implementing strategic policy was the Berlin Airlift.
Military logistics has pioneered a number of techniques that have since become widely deployed in the commercial world. Operations research
Operations research
Operations research is an interdisciplinary mathematical science that focuses on the effective use of technology by organizations...
grew out of WWII military logistics efforts. Likewise, military logistics borrows from methods first introduced to the commercial world.
The Kargil Conflict in 1999 between India and Pakistan also referred to as Operation Vijay (Victory in Hindi) is one of the most recent examples of high altitude warfare in mountainous terrain that posed significant logistical problems for the combating sides. The Stallion which forms the bulk of the Indian Army’s logistical vehicles proved its reliability and serviceability with 95% operational availability during the operation.
Loss of Strength Gradient
Geographic distanceDistance
Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, or an estimation based on other criteria . In mathematics, a distance function or metric is a generalization of the concept of physical distance...
is a key factor in military affairs. The shorter the distance, the greater the ease with which force can be brought to bear upon an opponent. This is because it is easier to undertake the supply of logistics to a force on the ground as well as engage in bombardment
Bombardment
A bombardment is an attack by artillery fire directed against fortifications, troops or towns and buildings.Prior to World War I the term term was only applied to the bombardment of defenceless or undefended objects, houses, public buildings, it was only loosely employed to describe artillery...
. The importance of distance is demonstrated by the Loss of Strength Gradient
Loss of Strength Gradient
The Loss of Strength Gradient was devised by Kenneth Boulding in 1962. He argued that the amount of a nation’s military power that could be brought to bear in any part of the world depended on geographic distance. The Loss of Strength Gradient demonstrated, in graphical form, that the further away...
devised by Kenneth Boulding. This shows the advantage of supply that is forward based.
U.S. Armed Forces classes of supply
The United States Military logistics support is grouped into 10 classes of supply:| Class | Description | Consumer Class |
|---|---|---|
| Class I | Subsistence (food), gratuitous (free) health and comfort items. | Troops |
| Class II | Clothing, individual equipment, tent-age, organizational tool sets and kits, hand tools, unclassified maps, administrative and housekeeping supplies and equipment. | Troops |
| Class III | Petroleum, Oil and Lubricants (POL) (package and bulk): Petroleum, fuels, lubricants, hydraulic and insulating oils, preservatives, liquids and gases, bulk chemical products, coolants, deicer and antifreeze compounds, components, and additives of petroleum and chemical products, and coal. | Equipment |
| Class IV | Construction materials, including installed equipment and all fortification and barrier materials. | Troops |
| Class V | Ammunition of all types, bombs, explosives, mines, fuzes, detonators, pyrotechnics, missiles, rockets, propellants, and associated items. | Equipment |
| Class VI | Personal demand items (such as health and hygiene products, soaps and toothpaste, writing material Writing material Writing material refers to the materials that provide the surfaces on which humans use writing instruments to inscribe writings. The same materials can also be used for symbolic or representational drawings. Building material on which writings or drawings are produced are not included... , snack food, beverages, cigarettes, batteries, alcohol Alcoholic beverage An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption... , and cameras—nonmilitary sales items). |
Troops |
| Class VII | Major end items such as launchers, tanks, mobile machine shops, and vehicles. | Equipment |
| Class VIII | Medical material (equipment and consumables) including repair parts peculiar to medical equipment. (Class VIIIa – Medical consumable supplies not including blood & blood products; Class VIIIb – Blood & blood components (whole blood, platelets, plasma, packed red cells, etc.). | Troops |
| Class IX | Repair parts and components to include kits, assemblies, and sub-assemblies (repairable Repairable Repairable is a military logistics term for a hardware component of a weapons system that can be designated for repair.Repairable components tend to be more expensive than non-repairable components, known as consumables. This is because for items that are inexpensive to procure, it is often more... or non-repairable) required for maintenance support of all equipment. |
Equipment |
| Class X | Material to support nonmilitary programs such as agriculture and economic development (not included in Classes I through IX). | Civilians |
| Miscellaneous | Water, salvage, and captured material. | Troops |
Supply chain management in military logistics often deals with a number of variables in predicting cost, deterioration, consumption, and future demand. The US Military's categorical supply classification was developed in such a way that categories of supply with similar consumption variables are grouped together for planning purposes. For instance peacetime consumption of ammunition and fuel will be considerably less than wartime consumption of these items, whereas other classes of supply such as subsistence and clothing have a relatively consistent consumption rate regardless of war or peace. Troops will always require uniform and food. More troops will require equally more uniforms and food.
In the table above, each class of supply has a consumer. Some classes of supply have a linear demand relationship - as more troops are added more supply items are needed - as more equipment is used more fuel and ammo is consumed. Other classes of supply must consider a third variable besides usage and quantity: time. As equipment ages more and more repair parts are needed over time, even when usage and quantity stays consistent. By recording and analyzing these trends over time and applying to future scenarios, the US Military can accurately supply troops with the items necessary at the precise moment they are needed. History has shown that good logistical planning creates a lean and efficient fighting force. Lack thereof can lead to a clunky, slow, and ill-equipped force with too much or too little supply.
Logistics related
- Aerial refuelingAerial refuelingAerial refueling, also called air refueling, in-flight refueling , air-to-air refueling or tanking, is the process of transferring fuel from one aircraft to another during flight....
- Airlift (military)Airlift (military)An airlift is the organized delivery of supplies or personnel primarily via aircraft.Airlifting consists of two distinct types, strategic and tactical airlifting...
- Army engineering maintenanceArmy engineering maintenanceArmy engineering maintenance consists of those engineers, technicians,and military organizations responsible for the expert repair and maintenance of army vehicles, weapon systems, and other equipment....
- Expeditionary maneuver warfareExpeditionary maneuver warfareExpeditionary maneuver warfare is the current concept that guides how the United States Marine Corps organizes, deploys and employs its forces...
- Integrated logistics supportIntegrated logistics supportIntegrated logistics support is an integrated approach to the management of logistic disciplines in the military, similar to commercial product support or customer service organisations...
- Line of communicationLine of communicationA line of communication is the route that connects an operating military unit with its supply base. Supplies and reinforcements are transported along the line of communication. Therefore, a secure and open line of communication is vital for any military force to continue to operate effectively...
or communications (LOC) - Logistician
- Logistics OfficerLogistics OfficerA Logistics Officer is a member of an armed force responsible for overseeing the support of an army, air force, or navy both at home and abroad. Logistics Officers can be stationary on military bases or deployed as an active part of a field army, air wing, or naval force. The responsibilities of...
- Military supply chain managementMilitary Supply Chain ManagementMilitary supply chain management is a cross-functional approach to procuring, producing and delivering products and services. The broad management scope includes sub-suppliers, suppliers, internal information and funds flow.-Supply:...
- NATO Stock NumberNATO Stock NumberA NATO Stock Number, or National Stock Number as it is known in the US, is a 13-digit numeric code, identifying all the 'standardized material items of supply' as they have been recognized by all NATO countries including United States Department of Defense...
- Performance-based logistics
- SeabasingSeabasingSeabasing is a naval capability that provides commanders with the ability to conduct selected functions and tasks at sea without reliance on infrastructure ashore. It describes the concepts and methods for sustaining large military forces during operations at large distances from traditional...
- SealiftSealiftSealift is a term used predominantly in military logistics and refers to the use of cargo ships for the deployment of military assets, such as weaponry, vehicles, military personnel, and supplies...
- Train (military)Train (military)In military contexts a train can refer to logistic elements of a force or organisation. In this context the term train usually does not mean a railway train.Historically and for land forces, this usually referred to troops that are endowed with horses...
- Underway replenishmentUnderway replenishmentUnderway replenishment or replenishment at sea is a method of transferring fuel, munitions, and stores from one ship to another while under way.-History:...
Further reading
-
- Biography of Brehon B. SomervellBrehon B. SomervellBrehon Burke Somervell was a General in the United States Army and Commanding General of the Army Service Forces in World War II. As such he was responsible for the U.S. Army's logistics...
, head of the United States ArmyUnited States ArmyThe United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
's Army Service ForcesArmy Service ForcesThe Army Service Forces were one of the three autonomous components of the Army of the United States during World War II, the others being the Army Air Forces and Army Ground Forces. They were created on February 28, 1942 by Executive Order Number 9082 "Reorganizing the Army and the War Department"...
during World War IIWorld War IIWorld War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.