Question

What was a primary reason President Truman decided to use the atomic bomb?

A. The leaders of the other Allied nations believed Japan was
preparing to invade Russia.
B. An Allied invasion of Japan was estimated to result in 1 million
Allied casualties.
C. The Allied forces were too weakened from fighting Germany to also defeat Japan.
D. Using the bomb would be U.S. retaliation for the attack on Pearl
Harbor.

Answer 1

B. An Allied invasion of Japan was estimated to result in 1 million Allied casualties.

President Truman decided to use the atomic bomb because an Allied invasion of Japan was estimated to result in 1 million casualties, both among Allied forces and Japanese civilians. The bombing of Hiroshima and Nagasaki convinced Japan's leaders to surrender, thus bringing a swift end to the war and avoiding the need for an invasion