Answer:
1.) He wanted to quickly end the war in the Pacific without invading Japan.
2.) Outraged by the attack on Pearl Harbor, Roosevelt asked Congress to declare war on Japan.
Step-by-step explanation:
1.) The war had been dragging on, and President Truman thought that this would end the war.
2.) America was known for its isolationist attitude towards the problems in Europe both during economic depression before the war, which was potentially caused the expansion of Nazism and the possibility of war, as well as the issue of World War II itself. It changed after the Japanese attack on Perl Harbor in 1941, when the entire American public was shocked and outraged, after which America declared the war on Japan.