Why do wars occur?

Understanding the causes of war is one way (possibly) to prevent it. World War II is used as a case study to facilitate an understanding of reasons why wars start. Topics covered included Totalitarianism, scarcity of resources, need for political and economic freedom. Unfortunately this presentation delves deeper into aspects and facts of WWII and fails to act as a true case study. It's still a wonderful slide-show on WWII and even includes quiz questions.