As one of my professors once pointed out, we would have never dropped it on the Germans.That tiresome old canard again, that racism was behind Hiroshima and Nagasaki. This must have been your professor of Historical Revisionism.
The whole Manhattan Project was STARTED because of German progress in nuclear research. Because of that progress, in 1939 Albert Einstein wrote his famous letter to FDR about the threat of a nuclear-armed Nazi Germany.
Just how seriously the Allies took that threat can be determined by one of the most bizarre missions of WWII. In 1944, German physicist Werner Heisenberg gave a lecture in Zurich, Switzerland. The OSS (ancestor of the CIA) sent an agent to Zurich with orders to stand up and shoot Heisenberg immediately if he mentioned an atomic bomb. The potential assassin was the fascinating character Mo Berg: pro baseball pitcher, graduate of Columbia Law School and fluent German speaker.
As a side note, even the aircraft that dropped the first atomic bomb, the B-29, was developed to use against Germany. With war looming for America in 1940 and the battle of Britan far from certain, the U.S. had to design aircraft capable of bombing Europe directly from America. That was the impetus for the B-29 (and its lesser-known sister, the B-32 Dominator).
By 1944, Germany's V-1 and V-2 missiles were devastating London, and Hitler was ranting daily about even better "miracle weapons" to come. The Allies had to assume one of those weapons might be nuclear. The absolute nightmare was a V-2 missile with a nuclear warhead.
And on that subject, there's this fascinating historical note. The British wanted to threaten Hitler with a nuclear weapon almost a year before it even existed:
One of Britain's most senior intelligence officers wanted the wartime leader, Winston Churchill, to threaten to drop atomic bombs on Nazi Germany a year before they were first used on Japan.
The scheme was seriously intended to be urged on the US president, Franklin Roosevelt, as a retaliation if V2 rockets were fired on British cities.
The call came from MI5's chief spycatcher, Guy Liddell, and revealed in his 12-volume private diaries, disclosed today by the public record office under the 60 year rule...
The idea of a nuclear threat figures in an entry on August 22, 1944. It was in response to warnings from agents that Germany was about to start attacking London with V2s, the most dreaded weapon used against civilians in the war. Britain had known the V2 was under development since 1942.
Liddell wrote: "I told about the plan for threatening the Germans with the uranium bomb if they threatened to use the V2".
On August 25, he saw the MI5 head, Sir Stewart Menzies, about the issue...
In advocating a nuclear threat, Liddell and Menzies were either apparently urging a policy based on sheer bluff - or were unaware that work to develop a uranium-based bomb was nowhere near ready. Liddell believed it was far advanced. But the first test explosion was not carried out till nearly 11 months later, in Los Alamos, New Mexico. http://www.buzzle.com/editorials/12-2-2002-31409.asp