War

[3] 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.

[6] Anthropologists disagree about whether warfare was common throughout human prehistory, or whether it was a more recent development, following the invention of agriculture or organised states.

Some sources claim that most Middle and Upper Paleolithic societies were possibly fundamentally egalitarian[12][13][14][15] and may have rarely or never engaged in organized violence between groups (i.e.

[21] In 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,[22] and many fought constantly.

[28] 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.

In every war in which American soldiers have fought in, the chances of becoming a psychiatric casualty – of being debilitated for some period of time as a consequence of the stresses of military life – were greater than the chances of being killed by enemy fire.Swank and Marchand's World War II study found that after sixty days of continuous combat, 98% of all surviving military personnel will become psychiatric casualties.

[89] Most wars have resulted in significant loss of life, along with destruction of infrastructure and resources (which may lead to famine, disease, and death in the civilian population).

A medium-sized conflict with about 2,500 battle deaths reduces civilian life expectancy by one year and increases infant mortality by 10% and malnutrition by 3.3%.

[94] Since a high proportion of those killed were young men who had not yet fathered any children, population growth in the postwar Soviet Union was much lower than it otherwise would have been.

[110] This aggressiveness is fueled by displacement and projection where a person transfers his or her grievances into bias and hatred against other races, religions, nations or ideologies.

The Italian psychoanalyst Franco Fornari, a follower of Melanie Klein, thought war was the paranoid or projective "elaboration" of mourning.

[111] Fornari thought war and violence develop out of our "love need": our wish to preserve and defend the sacred object to which we are attached, namely our early mother and our fusion with her.

Fornari focused upon sacrifice as the essence of war: the astonishing willingness of human beings to die for their country, to give over their bodies to their nation.

Some proponents of the idea argue that war, while innate, has been intensified greatly by developments of technology and social organization such as weaponry and states.

[118] Psychologist and linguist Steven Pinker argued that war-related behaviors may have been naturally selected in the ancestral environment due to the benefits of victory.

[121] Montagu's argument is supported by ethnographic research conducted in societies where the concept of aggression seems to be entirely absent, e.g. the Chewong and Semai of the Malay peninsula.

Marxist economists Karl Kautsky, Rosa Luxemburg, Rudolf Hilferding and Vladimir Lenin theorized that imperialism was the result of capitalist countries needing new markets.

Since the workers in a capitalist economy would be unable to fill the demand, producers must expand into non-capitalist markets to find consumers for their goods, hence driving imperialism.

[129] The violent herder–farmer conflicts in Nigeria, Mali, Sudan and other countries in the Sahel region have been exacerbated by land degradation and population growth.

[133][134] Heinsohn saw both past "Christianist" European colonialism and imperialism, as well as today's Islamist civil unrest and terrorism as results of high birth rates producing youth bulges.

Discipline came from drills and marching in formation, target practice, and creating small "artificial kinship groups: such as the company and the platoon, to enhance psychological cohesion and combat efficiency.

"Information asymmetry with incentives to misrepresent" occurs when two countries have secrets about their individual capabilities, and do not agree on either: who would win a war between them, or the magnitude of state's victory or loss.

[147] Within the rationalist tradition, some theorists have suggested that individuals engaged in war suffer a normal level of cognitive bias,[148] but are still "as rational as you and me".

Critics respond that military force may sometimes be at least as effective as trade at achieving economic benefits, especially historically if not as much today.

[154]: 150 These theories suggest differences in people's personalities, decision-making, emotions, belief systems, and biases are important in determining whether conflicts get out of hand.

[162] The principle of discrimination determines who are the legitimate targets in a war, and specifically makes a separation between combatants, who it is permissible to kill, and non-combatants, who it is not.

A ceasefire is a stoppage of a war in which each side agrees with the other to suspend aggressive actions often due to mediation by a third party.

Ceasefires may be intended to meet short-term limited needs (such as providing humanitarian aid), manage a conflict to make it less devastating, or advance efforts to peacefully resolve a dispute.

[169] An actor may not always intend for a ceasefire to advance the peaceful resolution of a conflict but instead give the actor an upper hand in the conflict (for example, by re-arming and repositioning forces or attacking an unsuspecting adversary), which creates bargaining problems that may make ceasefires less likely to be implemented and less likely to be durable if implemented.

[170][169][171] The durability of ceasefire agreements is affected by several factors, such as demilitarized zones, withdrawal of troops and third-party guarantees and monitoring (e.g. peacekeeping).