After remaining primarily isolationist through the 1920s, in the 1930s, the U.S. became increasingly involved in world
affairs and took a leading role in maintaining world order. The supporters of the Kellogg-Briand Pact hoped to initiate the
process toward the outlawing of war. The Clark Memorandum of 1930 repudiated the Roosevelt Corollary to the Monroe Doctrine.
The signatories of the Five Power Treaty at the Washington Conference in 1921 agreed to limit the size of their naives. The
Good Neighbor Policy promised Latin American countries a cooperative, rather than paternalistic, relationship with the U.S.
in 1931, the illusion of peace was shattered by the Japanese invasion of Manchuria. The dictator of Fascist Italy was
Benito Mussolini. Britain and France responded to initial German aggression by attempting to appease Hitler. The outbreak
of war in Europe in 1939, Franklin D. Roosevelt declared American neutrality. The Lend-Lease Act of 1941 ensured the British easier
access to American war supplies. The American fleet at Pearl Harbor was caught by surprise when Japan attacked because of
human miscalculations and mistakes.