President Franklin D. Roosevelt said the United States needed to become the "great arsenal of democracy" mainly because he was trying to assist the Allied nations. This is the correct answer to the question.
By providing military aid and support to the Allied nations during World War II, the United States played a crucial role in helping these countries fight against the Axis powers. Becoming the "great arsenal of democracy" meant that the U.S. would supply weapons, equipment, and resources to support the war effort of its allies, contributing to the overall goal of defeating the enemy forces.
This decision was significant in shaping the outcome of the war and showcasing the United States as a key player in promoting democracy and freedom globally. Through this assistance, President Roosevelt aimed to strengthen alliances, promote shared values, and contribute to the eventual victory of the Allied powers.
