The quote below was taken from a speech given on august 29, 1945, to engineers on the manhattan project by the military commander in charge of the project: "the only thing that we have to think about is that the war is over and that a great many of [sic] americans are going to be safe and in good hands who wouldn't have been if it hadn't been for the manhattan district " --general leslie grove why would grove have told the engineers "the only thing we have to think about is that the war is over"? the decision to use atomic weapons was opposed by some who felt it was immoral. the decision to use atomic weapons was not supported by most americans the decision to use atomic weapons prolonged the war against japan. the decision to used atomic weapons allowed german scientists to develop similar weapons.