"By far, the most destructive aftershock of World War I was World War II, coming a mere 20 years after the Treaty of Versailles. While the rise of the Nazis in Germany in the 1930's generally took center stage, events elsewhere, some of them as far away as East Asia, also contributed to the outbreak of war. Three main factors, all resulting from World War I, would lead to war: the Treaty of Versailles, the Great Depression, and the Russian Revolution."

Source: Chris Butler, http://www.flowofhistory.com

The quicktime file as PPT:

Task: You, as the president of the great nation of Yusistan, are appalled at the aftermath of World War I and determine to do something about preventing such a thing from happening again. You come up with a plan for preventing wars and your vision is global. You think that after this event, the powers of the world will be able to be persuaded to join you. What's your plan?