Franklin D. Roosevelt's strategy ended in the defeat of the Allies.
The Axis powers ( Achsenmächte , 枢軸国 Sūjikukoku , Potenze dell ` Asse ) , also known as the Rome -- Berlin -- Tokyo Axis , were the nations that fought in World War II against the Allied Powers . Franklin D. Roosevelt . As an active military leader , Roosevelt implemented a war strategy on two fronts that ended in the defeat of the Axis Powers , and he initiated the development of the world 's first atomic bomb .