War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents and militias. It is generally characterized by extreme violence, aggression, destruction, and mortality, using regular or irregular military forces. 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.
|Clockwise from top left: Ancient warfare: Stele of the Vultures, c 2500 BC. Medieval warfare: Battle of Hastings, 1066. Early modern warfare: Retreat from Moscow, 1812. Industrial age warfare: Battle of the Somme, 1916. Modern warfare: Into the Jaws of Death, 1944. Nuclear warfare: Nuclear weapon test, 1954.|
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While some scholars see war as a universal and ancestral aspect of human nature, others argue it is a result of specific socio-cultural, economic or ecological circumstances.