This three-page undergraduate essay analyzes the three great wars of the twentieth century, examines how they started, where they were fought, and how they changed the world. The author notes that these three great wars were linked together by political, military, nationalist, and ideological sequences of cause-and-effect. In many ways, The Great War caused World War II, and World War II caused the Cold War, for the aftermath of each war created conditions that led to the outbreak of new conflict.