This chapter discusses international diplomacy and America's changing role in the world from 1921-1941. It covers topics like early 20th century agreements like the Kellogg-Briand Pact, the rise of isolationism in the 1930s as shown by the Neutrality Acts, President Roosevelt's increasing efforts to aid allies like the Lend-Lease program, and concludes with Japan's attack on Pearl Harbor that led to America's entry into World War II.