Throughout history we see that continuity and change have characterized the history of the world. Also, history ultimately repeats itself. In many instances throughout history we see the rising and falling of many nations, leaders, militias, etc. Many of these stick in my mind, such as the Rationalist's (John Locke, Voltaire, Montesqiue, and Rousseau) in France, or the Revolutionary War led by the Continental Army and George Washington, or General Napolean Bonaparte and his rise to power and dramatic downfall in Russia, or the two great World Wars, or Hitler and his racial hierarchy which was centered around the Aryan race, Anti-Semitism, and the extermination of the Jewish race and culture. .
All of these people and things are examples of how the world dramatically changed just through each nations leaders and ideas. Throughout history there have been many people and cultures that were labeled as "others."" First to mind is the Jews during World War II. Hitler's Anti-Semitic ideas of having the pure Aryans (Germans) ruling over the non-pure Aryans (British, Dutch, and Scandinavians), the Latin's (Italian, French, and Spanish), the Slavs who would be used as slave laborers, and lastly the Jews who were to be dealt with at the extermination death camps which used gas chambers and crematories and were spread all across Europe (Mostly in Poland and Germany.) The Jews were labeled as others because of one man's hatred for them. Hitler felt that the Jews ruled too much and the Germans ruled not enough.
Historically we have come to accept war for many reasons, they are to support the fighting cause, for imperialism or colonization, to boost ones economy, or simply for freedom. In history, war has been used as a center of nationalism and pride. If a nation wins a war they linger on it for ages; it shows muscle. The United States, for example, has been in many wars. An example is the Revolutionary War, which was started by militiamen who were fighting the great British Army.