The International Day for Preventing the Exploitation of the Environment in War and Armed Conflict was established on November 5, 2001 by the United Nations General Assembly, during Kofi Atta Annan's tenure as Secretary-General. Of this observance Secretary-General Ban Ki-moon has since written, "We must use all of the tools at our disposal, from dialogue and mediation to preventive diplomacy, to keep the unsustainable exploitation of natural resources from fueling and financing armed conflict and destabilizing the fragile foundations of peace." Various calendars found on the World Wide Web reference November 6th in abbreviated fashion as 'World Day to Protect the Environment in War.
War is a state of armed conflict between states, governments, societies and informal 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.
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.
The earliest evidence for prehistoric warfare belongs to the Mesolithic cemetery Site 117, which has been determined to be approximately 14,000 years old. About forty-five percent of the skeletons there displayed signs of violent death. Since the rise of the state some 5,000 years ago, military activity has occurred over much of the globe. The advent of gunpowder and the acceleration of technological advances led to modern warfare. According to Conway W. Henderson, "One source claims that 14,500 wars have taken place between 3500 BC and the late 20th century, costing 3.5 billion lives, leaving only 300 years of peace (Beer 1981: 20)." An unfavorable review of this estimate mentions the following regarding one of the proponents of this estimate: "In addition, perhaps feeling that the war casualties figure was improbably high, he changed "approximately 3,640,000,000 human beings have been killed by war or the diseases produced by war" to "approximately 1,240,000,000 human beings. Primitive warfare is estimated to have accounted for 15.1 per cent of deaths and claimed 400 million victims. For comparison, an estimated 1,680,000,000 people died from infectious diseases in the 20th century. Nuclear warfare breaking out in August 1988, when nuclear arsenals were at peak level, and the aftermath thereof, could have reduced human population from 5,150,000,000 by 1,850,000,000 to 3,300,000,000 within a period of about one year, according to a projection that did not consider "the most severe predictions concerning nuclear winter". This would have been a proportional reduction of the world’s population exceeding the reduction caused in the 14th century by the Black Death, and comparable in proportional terms with the plague’s impact on Europe's population in 1346–53.
In War Before Civilization, Lawrence H. Keeley, a professor at the University of Illinois, says approximately 90–95 per cent 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 organised in a relatively advanced way, were renowned for their studied cruelty...'archaeology yields evidence of prehistoric massacres more severe than any recounted in ethnography after the coming of the Europeans.