Answer :
One cause of WWII was the death of Archduke Ferdinand, Pearl Harbor was what caused the US to enter the war, Japan was a member of the Axis Powers, and Franklin D Roosevelt was president for most of the war.
Answer:
1. Treaty failure caused WWII, not Ferdinand assassination. That was WWI. 2. Pearl Harbour 3. Japan and 4. (I think) Franklin Roosevelt.
Explanation:
I'm late, but here.