不戦条約
In 1928 the two nations were the chief sponsors of the Kellogg–Briand Pact which outlawed war. The pact, which was endorsed by most major nations, renounced the use of war, promoted peaceful settlement of disputes, and called for collective force to prevent aggression. Its provisions were incorporated into the United Nations Charter and other treaties and it became a stepping stone to a more activist American policy. Diplomatic intercourse was minimal under Franklin D. Roosevelt from 1933 to 1939.