When and why did the US enter World War 2?
the US joined WWII because of the attack on pearl harbor which
took place 7th of December, 1941, the US joined quickly after
America joined WW2 shortly after the Pearl Harbor bombing. Japan and the US were on hot ground, fighting over oil pipes in Japan.
In December 1941, after the Japanese attacked Pearl Harbor resulting in the loss of several ships and the deaths of 2,000 sailors, despite the fact the nations were not at war with each other. Japan was anticipating war with the US, especially after the Americans stopped supplying oil and moved their Pacific fleet to Hawaii.
For the most part, the American public had no desire to enter World War 2. Though they empathized and even provided material support to Britain and Canada, the people wished to remain neutral. However, US leadership was anxious to go to war with Germany, and were able to do so upon Japan's attack on Pearl Harbor. Hitler actually made this easier on Roosevelt by declaring war on the US, as Roosevelt was going to have…