War is an armed conflict between the armed forces of states, or between governmental forces and armed groups that are organized under a certain command structure and have the capacity to sustain military operations, or between such organized groups.
It is generally characterized by widespread violence, destruction, and mortality, using regular or irregular military forces. War aims typically involve the pursuit of political, economic, or territorial objectives. Warfare refers to the common activities and characteristics of types of war, or of wars in general. Total war is warfare that is not restricted to purely legitimate military targets, and can result in massive civilian or other non-combatant suffering and casualties.
War has changed in numerous ways over the course of history. Since 1945, great power wars, territorial conquests and war declarations have declined in frequency.
History
thumb|left|Cave painting in Galeria del Roure, in [[Morella, Spain|Morella la Vella depicting archery combat.]]Anthropologists disagree about whether warfare was common throughout human prehistory, or whether it was a more recent development, following the invention of agriculture or organized states. It is difficult to determine whether warfare occurred during the Paleolithic due to the sparsity of known remains. Some sources claim that most Middle and Upper Paleolithic societies were possibly fundamentally egalitarian and may have rarely or never engaged in organized violence between groups (i.e. war). Evidence of violent conflict appears to increase during the Mesolithic period, from around 10,000 years ago onwards. In his book Warless Societies and the Origin of War he explores the origins of modern wars and states that high surplus product encourages conflict, so "raiding often begins in the richest environments".
In his 1996 book War Before Civilization, Lawrence H. Keeley, a professor at the University of Illinois, says approximately 90–95% of known societies throughout history engaged in at least occasional warfare, and many fought constantly. Keeley describes several styles of primitive combat such as small raids, large raids, and massacres. All of these forms of warfare were used by primitive societies, a finding supported by other researchers. Keeley explains that early war raids were not well organized, as the participants did not have any formal training. Scarcity of resources meant defensive works were not a cost-effective way to protect the society against enemy raids. William Rubinstein wrote "Pre-literate societies, even those organized in a relatively advanced way, were renowned for their studied cruelty.'"
Since the rise of the state some 5,000 years ago, military activity has continued over much of the globe. In Europe the oldest known battlefield is thought to date to 1250 BC. The Bronze Age has been described as a key period in the intensification of warfare, with the emergence of dedicated warriors and the development of metal weapons like swords. Two other commonly named periods of increase are the Axial Age and Modern Times. The invention of gunpowder, and its eventual use in warfare, together with the acceleration of technological advances, have fomented major changes to war itself.
thumb|right|upright=1.4|The percentages of men killed in war in eight tribal societies, and Europe and the U.S. in the 20th century. (Lawrence H. Keeley, archeologist)
In Coercion, Capital, and European States, AD 990–1992, Charles Tilly argued that "war made the state, and the state made war", saying that wars have led to creation of states which in their turn perpetuate war. Tilly's theory of state formation is considered dominant in the state formation literature.
thumb|American tanks moving in formation during the [[Gulf War]]
Since 1945, great power wars, territorial conquests and war declarations have declined in frequency. Wars have been increasingly regulated by international humanitarian law. and despite advances in weapons. In Western Europe, since the late 18th century, more than 150 conflicts and about 600 battles have taken place, but no battle has taken place since 1945.
However, war in some aspects has not necessarily declined. The major exceptions were the Korean War, the Indo-Pakistani War of 1971, the Iran–Iraq War, the Gulf War, the Eritrean–Ethiopian War, and the Russo-Ukrainian War.
Types of warfare
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- Asymmetric warfare is the methods used in conflicts between belligerents of drastically different levels of military capability or size.
- Biological warfare, or germ warfare, is the use of biological infectious agents or toxins such as bacteria, viruses, and fungi against people, plants, or animals. This can be conducted through sophisticated technologies, like cluster munitions, or with rudimentary techniques like catapulting an infected corpse behind enemy lines, and can include weaponized or non-weaponized pathogens.
- Chemical warfare involves the use of weaponized chemicals in combat. Poison gas as a chemical weapon was principally used during World War I, and resulted in over a million estimated casualties, including more than 100,000 civilians.
- Cold warfare is an intense international rivalry without direct military conflict, but with a sustained threat of it, including high levels of military preparations, expenditures, and development, and may involve active conflicts by indirect means, such as economic warfare, political warfare, covert operations, espionage, cyberwarfare, or proxy wars.
- Conventional warfare is a form of warfare between states in which nuclear, biological, chemical or radiological weapons are not used or see limited deployment.
- Cyberwarfare involves the actions by a nation-state or international organization to attack and attempt to damage another nation's information systems.
- Insurgency is a rebellion against authority, where irregular forces take up arms to change an existing political order. An insurgency can be fought via counterinsurgency, and may also be opposed by measures to protect the population, and by political and economic actions of various kinds aimed at undermining the insurgents' claims against the incumbent regime.
- Information warfare is the application of destructive force on a large scale against information assets and systems, against the computers and networks that support the four critical infrastructures (the power grid, communications, financial, and transportation).
- Nuclear warfare is warfare in which nuclear weapons are the primary, or a major, method of achieving capitulation.
- Radiological warfare is any form of warfare involving deliberate radiation poisoning or contamination of an area with radiological sources.
- Total war is warfare by any means possible, disregarding the laws of war, placing no limits on legitimate military targets, using weapons and tactics resulting in significant civilian casualties, or demanding a war effort requiring significant sacrifices by the friendly civilian population.
- Unconventional warfare can be defined as "military and quasi-military operations other than conventional warfare" and may use covert forces or actions such as subversion, diversion, sabotage, espionage, biowarfare, sanctions, propaganda or guerrilla warfare.
Aims
thumb|[[United States Army soldiers engaged in a firefight with Taliban insurgents during the War in Afghanistan, 2009]]
Entities contemplating going to war and entities considering whether to end a war may formulate war aims as an evaluation/propaganda tool. War aims may stand as a proxy for national-military resolve.
Definition
Fried defines war aims as "the desired territorial, economic, military or other benefits expected following successful conclusion of a war".
Classification
Tangible/intangible aims:
- Tangible war aims may involve (for example) the acquisition of territory (as in the German goal of Lebensraum in the first half of the 20th century) or the recognition of economic concessions (as in the Anglo-Dutch Wars).
- Intangible war aims – like the accumulation of credibility or reputation – may have more tangible expression ("conquest restores prestige, annexation increases power").
Explicit/implicit aims:
- Explicit war aims may involve published policy decisions.
- Implicit war aims can take the form of minutes of discussion, memoranda and instructions.
Positive/negative aims:
- "Positive war aims" cover tangible outcomes.
- "Negative war aims" forestall or prevent undesired outcomes.
War aims can change in the course of conflict and may eventually morph into "peace conditions" – the minimal conditions under which a state may cease to wage a particular war.
Effects
thumb|upright=1.35|Global deaths in conflicts since the year 1400.
Conflict zones
When a war takes place, one or more areas within a country or across border becomes a war zone or conflict zone. Daily life is interrupted, travel to or across the area may be difficult and international visitors may be advised to leave the area.
Casualties
thumb|upright=1.35|[[Disability-adjusted life year for war per 100,000 inhabitants in 2004
]]
Estimates for total deaths due to war vary widely. In one estimate, primitive warfare from 50,000 to 3000 BCE has been thought to have claimed 400million±133,000 victims based on the assumption that it accounted for the 15.1% of all deaths. Ian Morris estimated that the rate could be as high as 20%. Other scholars find the prehistoric percentage much lower, around 2%, similar to the Neanderthals and ancestors of apes and primates.
For the period 3000 BCE until 1991, estimates range from 151million to severalbillion. The lowest estimate for history of 151 million was calculated by William Eckhardt. He explained his method as summing the recorded casualties and multiplying their average by the number of recorded battles or wars. This method excludes indirect deaths for premodern wars and all deaths for unrecorded wars. Few premodern wars were recorded beyond Eurasia and only 18 wars were recorded for period 3000 - 1500 BC worldwide.
Data cumulated since the research of Eckhardt, especially for the non-European world, was collected in this list. Averaging the ranges it provided, the total for 500 BC - 2023 AD is about 570 million, or 0.95% of people born in the same period, of them 58 million for 500 BC - AD 500, 117 million for AD 500 - 1700, and 396 million for 1700 - 2023.
Meanwhile, researchers shifted from Eckhardt's approach to general estimations of the percentage of the population killed by wars. Azar Gat and Ian Morris both give the lowest estimate of 1% for history including all the 20th century, or about 1 billion. The highest estimates of both scholars exceed the famous "hoax" of 3,640,000,000 people killed in wars which circulated decades in scholarly literature in various countries. Gat gives 5%, or about 5 billion. Morris gives for the 20th century 2%, for 1400-1900 3% in Europe and "slightly higher" elsewhere, 5% for the ancient empires in 500 BC - AD 200, 10% for the rest of history and 20% for prehistory. His total for history is thus about 9 billion.
Largest wars by death toll
The deadliest war in history, in terms of the cumulative number of deaths since its start, is World War II, from 1939 to 1945, with 70–85 million deaths, followed by the Mongol conquests at up to 60 million. As concerns a belligerent's losses in proportion to its prewar population, the most destructive war in modern history may have been the Paraguayan War (see Paraguayan War casualties). War resulted in 31,000 deaths in 2013, down from 72,000 deaths in 1990.
War usually results in significant deterioration of infrastructure and the ecosystem, a decrease in social spending, famine, large-scale emigration from the war zone, and often the mistreatment of prisoners of war or civilians. For instance, of the nine million people who were on the territory of the Byelorussian SSR in 1941, some 1.6 million were killed by the Germans in actions away from battlefields, including about 700,000 prisoners of war, 500,000 Jews, and 320,000 people counted as partisans (the vast majority of whom were unarmed civilians). Another byproduct of some wars is the prevalence of propaganda by some or all parties in the conflict, and increased revenues by weapons manufacturers.
Three of the ten most costly wars, in terms of loss of life, have been waged in the last century. These are the two World Wars, followed by the Second Sino-Japanese War (which is sometimes considered part of World War II, or as overlapping). Most of the others involved China or neighboring peoples. The death toll of World War II, being over 60 million, surpasses all other war-death-tolls.
{| class=wikitable
|-
! Deaths<br />(millions)
! Date
! War
|-
| || 1939–1945 || World War II (see World War II casualties)
|-
| || 13th century || Mongol Conquests (see Mongol invasions and Tatar invasions)
|-
| || 1850–1864 || Taiping Rebellion (see Dungan Revolt)
|-
| || 755–763 || An Lushan Rebellion (death toll uncertain)
|-
| || 1616–1662 || Qing dynasty conquest of Ming dynasty
|-
| || 1937–1945 || Second Sino-Japanese War
|-
| || 1370–1405 || Conquests of Tamerlane
|-
| || 1862–1877 || Dungan Revolt
|-
| || 1917–1922 || Russian Civil War and Foreign Intervention
|}
On military personnel
Military personnel subject to combat in war often suffer mental and physical injuries, including depression, posttraumatic stress disorder, disease, injury, and death.
