In 1940, the world was deeply affected by World War II, which had begun the previous year. Major events included the fall of France to Nazi Germany and the Battle of Britain, where the Royal Air Force defended the United Kingdom against German air attacks. This year marked a significant escalation in the conflict, with many countries becoming involved. In the United States, President Franklin D. Roosevelt was re-elected for a third term, emphasizing the need for national defense. Meanwhile, the Lend-Lease Act was introduced, allowing the U.S. to supply military aid to its allies, particularly Britain and China.