Later on, more liberal government policies were put into place; daimyo and officials were encouraged to take more ronin into their service as samurai. However, this option only could serve a minority of ronin; in an era of peace, few clans needed the large number of samurai that they would need in times of war.
The atomic bomb was not invented by any country, it was  invented in 1933 by Leo Szilard (he was in London at the time, so  when he patented the invention he sold it to the â¦ British Admiralty  who classified it to keep the idea away from the Nazis).
The Manhattan project was an initiative undertaken by president Franklin Roosevelt, to build an atomic bomb. It was going to be used against Nazi Germany, supposedly only if they developed nuclear weapons (which of course was a a great fear at the time).