We have wars because two or more groups cannot or were unable to agree with idea or beliefs through communication dialog. Eventually each group is forcing for other group to concede to his idea, rather than their own by force. When this force is used, it becomes a war.
War is good under the right circumstances. Just imagine if you were hiding under your bed from people who were trying to get you. If that has never happened to you in your life, it's probably because your country has a strong military and they aren't afraid to use it. It has happened to alot of people though, throughout history... hiding under their bed from Nazis or Ethnic Cleansing people.
Say I want your property ... You're too small to stop me, so I take it ... Another person tells me to give it back, but I refuse ... now what? Unless those who think I should give it back are willing to use force to make me (war) - I'm not giving it back, and you're out of luck. And then I keep taking things from you, and nobody stops me. Sure, they may call me a bad person and say they won't be my friend (sanctions) - but I don't care. >> Now do you understand why war is sometimes necessary?
Here it is short and sweet okay? think of it as population control if we don't have war we over populate and die anyway so war is an easy solution to our problems WHY NOT just kill of north Korea and call it a day... well we cant cause than china would be on us and so would half of Asia and most of Russia (not sure it is still a country) also as Walt said we need war to keep things! like for example world war 2 the Nazis were bad people at were killing Jews and being one myself i know that Nazis caused and are the Holocaust i understand Germany needed a leader to bad it turned out to be a physcobath! Anyhow i hope you now understand the evil that comes from war but that is human nature we want we take we not very bright when it comes to asking