Final answer:
The United States entered World War II in 1941 primarily because of Japan's attack on Pearl Harbor and tensions that had been building between the countries. This caused the U.S. to declare war on Japan.
Step-by-step explanation:
The correct answer is option History. The United States entered World War II in 1941 primarily because of Japan's attack on the U.S. naval base at Pearl Harbor.
This attack was the immediate cause for the U.S. to declare war on Japan. However, tensions between the United States and Japan, as well as the U.S.'s desire to assist the British and prevent a potential German invasion, had been building for some time.
The correct answer is option History. The United States entered World War II in 1941 primarily due to Japan's attack on Pearl Harbor. Prior to the attack, President Roosevelt had been supporting Britain against Nazi Germany and was concerned about the growing threat from the Axis powers.
However, American public opinion was largely isolationist until the attack, which united the country against a common enemy. After Pearl Harbor, Roosevelt delivered his famous "Day of Infamy" speech, urging Congress to declare war on Japan, which they did with overwhelming support.
Following this, Germany and Italy declared war on the United States, drawing the country fully into World War II.
Throughout the war, Roosevelt collaborated closely with Allied leaders like Winston Churchill to develop strategies for defeating the Axis powers, emphasizing the European theater first.
The war efforts also played a significant role in pulling the United States out of the economic struggles of the 1930s by massively increasing production and employment.
Roosevelt's leadership during the war helped lay the groundwork for the post-war order and established the United States' role as a global superpower.