It is USA.
If you have any disbelief, visit Hiroshima and its unique Gembaku (Atomic Bomb) musium beside the Gembaku Dome.
All the history is there.
Atomic Bomb
The US was the first country to develop the Atom bomb by the end of WWII and the president at the time (Harry Truman) used it to end WWII by droping it to Japan twice in different cities.
US
china
This is a massively complicated moral question. You will have to develop your own opinion.
Pakistan is the first and still the only Muslim country to make atomic bombs.
Yes, both.
Atomic Bomb
In what country was the plan devised to create an atomic bomb?
yes we did
The atomic bomb is too expensive to develop for a city to have them. They are weapons held only by industrialized countries.
USA
Manhattan Project
No, Albert Einstein did not develop the atomic bomb, which was developed by a team of researchers led by J. Robert Oppenheimer. Einstein's theoretical work does provide the basis upon which the bomb was developed.
Manhattan project
The Manhattan Project
Manhattan