WAR is a human Nature

War: is an organized and often prolonged conflict that is carried out by states or non-state actors. It is generally characterized by extreme violence, social disruption, and economic destruction. War should be understood as an actual, intentional and widespread armed conflict between political communities, and therefore is defined as a form of political violence or intervention. The set of techniques used by a group to carry out war is known as warfare. An absence of war is usually called peace.
Etymology:
The English word war derives from the late Old English (c.1050) words wyrre and werre; the Old North French werre; the Frankish werra; and the Proto-Germanic werso. The denotation of war derives from the Old Saxon werran, Old High German werran, and the German verwirren: “to confuse”, “to perplex”, and “to bring into confusion”.Another posited derivation is from the Ancient Greek barbaros, the Old Persian varhara, and the Sanskrit varvar and barbara. In German, the equivalent is Krieg; the equivalent Spanish, Portuguese, and Italian words for "war" is guerra, derived from the Germanic werra (“fight”, “tumult”).Etymologic legend has it that the Romanic peoples adopted a foreign, Germanic word for "war", to avoid using the Latin bellum, because, when sounded, it tended to merge with the sound of the word bello ("beautiful") Polemology- is the science and study of human conflict and war.
Behavior and conduct in war:
The behavior of troops in warfare varies considerably, both individually and as units or armies. In some circumstances, troops may engage in genocide, war rape and ethnic cleansing. Commonly, however, the conduct of troops may be limited to posturing and sham