War

War is a state of armed conflict between societies. It is generally characterized by extreme aggression, destruction, and mortality, using regular or irregular military forces. An absence of war is usually called peace.  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 casualties.

The deadliest war in history was World War 2, from 1939 to 1945, with 60–85 million deaths. followed by the Mongol conquest which was greater than 41 million. In 2013 war resulted in 31,0000 deaths, down from 72,000 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.

While some people see war as a universal aspect of human nature, to others it is a result of specific socio-cultural or ecological circumstances. Another byproduct of some wars is the prevalence of information by some or all parties in the conflict, and increased revenues by weapons manufacturers.