"All along, it has been a race with the enemy."

That the personnel of the Manhattan Project were in a race with Hitler Germany to develop the atomic bomb was a psychological device used by the Army to quell misgivings that some of the scientists might have had about the morality of developing such a weapon. It is also an ancient device of spurring people on to greater-than-normal effort.

While the idea of a German program to develop an atomic bomb was a prudent assumption early in the war, this assumption was never revised in the face of physical evidence to the contrary as it became available.

This unrelenting urgency at every level of the US government to develp and test the bomb on an inhabited city is consistent with the theory that the development of the atomic bomb was perceived as a weapon to achieve military superiority over the Soviet Union, one of the US' allies, after the defeat of the Axis Powers.