Most conflicts between people are a result of misunderstanding. The best way of clearing the misunderstanding and reconciling is through discussion between the two parties.
But Man–the intelligent, Man–the genius, Man–the cogitating animal, has thought of another way of clearing misunderstandings, and that is, by the abolition of the enemy. War seems to have become the way to resolve conflicts. In time, thinking Man will no longer exist and will be replaced by non-thinking animals, if they make it out alive in the world that Man has devised.
Perhaps one of the most abhorrent traits of Man is jealousy. There are other characteristics which you can describe as inherently evil, but jealousy or envy is at the root of most misperceptions. Tragically, most misperceptions are blown out of proportion.
Is it in the nature of man to be envious and to want things that belong to others? Perhaps so, from a toy belonging to another child, to natural resources belonging to another country, Man has shown his capacity to covet.
What you do not have, you must work hard for. But if Man has gotten it by means other than what is morally acceptable, not only is his nature shallow, but Man is no better than an animal who does not think.