The end of World War I did not bring peace and prosperity to Europe. The harsh peace terms imposed on the Central Powers in 1919 left the losers, especially Germany, deeply resentful. The war saddled both sides with a huge financial debt and produced economic instability, which contributed to the Great Depression. In the Far East, Japanese invasions of China and Southeast Asia threatened America’s Open Door policy (see “Opening the Door in China” in chapter 20). The failure of the United States to join the League of Nations dramatically reduced the organization’s ability to maintain peace and stability. German expansionism in Europe in the late 1930s moved President Roosevelt and the nation toward war, but it took the Japanese attack on Pearl Harbor to bring the United States into the global conflict.