Political Systems and War

When a culture decides to engage in a conflict on foreign soil, it often has ways in which to justify the cost (both the loss of money and the loss of lives). Discuss three reasons which have been promoted in history to invade foreign culture.
Be specific in your examples and cite scholarly evidence to support your argument: for example: America engaged in a military conflict in the 1960's-1970's in North Vietnam in order to prevent the spread of communism" (CNN - http://vvww.cnn.com/2014106/20/us/vietnam-war-five-things/). This fear of communism was fed by the Cold War and in turn allowed Americans to believe that it was the 'right thing to do'; we were not only justified in entering the conflict but were morally required based on the Judeo-Christian values prevalent in the U.S. in the 1960's.
Questions to consider:
• How does the justification represent the values and traditions of culture? • Do the justifications ever have a hidden agenda? • Does a certain group profit more from the conflict? • Does religion ever play a role in the justification?