The early twentieth century witnessed the breakdown of the international political and economic order. Great power rivalries, an arms race, competition for colonies and markets, and domestic turmoil contributed to the explosion in 1914. The First World War destroyed much of European civilisation by bringing an end to four empires, and greatly weakening the power of several others. Countries like the United States and Japan became key players in the new order. New ideologies and new forms of government developed as a result of the changes, giving rise to even more instability and conflict: evidenced in the rise of Mussolini, Stalin, and Hitler. The global economic crisis in the 1930s brought additional pressures that eventually erupted in another world war between 1939 and 1945. How and why did this happen? Why did Europe self-destruct? What about other countries? This course will explain the enormity of changes that occurred with First World War and the subsequent attempts to re-establish a stable international order in the 1920s and 1930s. We will also examine how and why these attempts failed, and why the Second World War occurred. A wide array of topics and events will be addressed, such as imperialism; nationalism; militarism; technological advancements; pressures for war; the Paris Peace Conference and dismantling of empires; ideological extremism and the rise of Hitler and Stalin; Japan’s conquests in Asia; the Great Depression; American isolationism; appeasement policy; the coming of WWII; the Holocaust; the atomic bomb; “total war”; and the development of a new “cold war” between the United States and the Soviet Union after 1945. In the process, we will examine the historical roots, structures, and problems that shape the international order today.