Cant anyone help me with this WWII genocide question?

3. Both the Germans and the Japanese were responsible for major genocides during World War II. Discuss these atrocities. What factors in twentieth century history have led to violence such as the Holocaust, the Nanjing Macre, Rwanda, Bosnia, the Sudan, etc.? What are the similarities and differences between these organized movements targeting those who are different? Why do you think this kind of ethnic violence is possible?