Why was the manhattan project kept top secret?
the united states did not want great britain or france to know that it had nuclear technology.
no one was sure if the atom bomb would actually ever work and they didn't want negative feedback.
the allies were afraid that the technology would be stolen by spies belonging to germany or japan.
the united states was developing the technology illegally and with stolen technology and materials.

Which of the following arguments decided the debate over using the atomic bomb against japan in 1945? using the bomb would destroy the armaments still available to japanese forces in japan. using the bomb would demonstrate the power of the united states to the entire world. using the bomb would shorten the war and avoid heavy casualties among invading troops. using the bomb would enable allied forces to invade and take over the japanese mainland