he set of techniques used by a group to carry out war is known as warfare. An absence of war is usually called peace. While some scholars see warfare as an inescapable and integral aspect of human nature,[1] others argue that it is only inevitable under certain socio-cultural or ecological circumstances.[2] For some, the practice of war is not linked to any single type of political organization or society. Rather, as discussed by John Keegan in his A History of Warfare, war is a universal phenomenon whose form and scope is defined by the society that wages it. Another argument suggests that since there are human societies in which warfare does not exist, humans may not be naturally disposed for warfare, which emerges under particular circumstances. The deadliest war in history, in terms of the cumulative number of deaths since its start, is the Second World War, with 60–85 million deaths, followed by the Mongol conquests.[3] Proportionally speaking, the most destructive war in modern history is the War of the Triple Alliance, which took the lives of over 60% of Paraguay's population, according to Steven Pinker. In 2003, Richard Smalley identified war as the sixth (of ten) biggest problems facing humanity for the next fifty years.
