"Arsenal of Democracy" was the central phrase used by U.S. President Franklin D. Roosevelt in a radio broadcast on the threat to national security, delivered on December 29, 1940—nearly a year before the United States entered the Second World War (1939–1945). Roosevelt promised to help the United Kingdom fight Nazi Germany by selling them military supplies while the United States stayed out of the actual fighting. The president announced that intent a year before the attack on Pearl Harbor, at a time when Germany had occupied much of Europe and threatened Britain.