A huge proponent to the use of the atomic bomb on Hiroshima and Nagasaki on August 6 and August 9 of 1945 was President Harry Truman. Although they value the ideas and contributions out in by the committee they choose, the president ultimately has the last say on war time decisions. It just so happens that President Truman wanted to drop the bomb. President Truman believed that Japan's leaders would not surrender to the terms outlined in Potsdam meeting. He saw it fit to drop the bombs and end all doubt.
Another man that backed the use of the atomic bombs was James Byrnes. Secretary of State, Byrnes was, in essence, Truman's right hand man. He did not want the Russians to get involved in the war in Asia and felt that the atomic bomb would keep them away.
One of the main opponents to the atomic bomb was William Leahy. Chief of Staffs to the president, Leahy saw the bombings as barbaric and unnecessary as he believed the war against the Japanese was already won. He believed war should not be won by killing women and children.
General Douglas MacArthur also believed that the dropping of the atomic bombs were militarily unjustified. He thought the war could have need ended without the use of them.
2) The first use of the atomic bomb by the United States has its pros and cons. However, when you look at it in perspective, it was a wise decision in diplomatic and political terms, but not so much in ethical