Why was it right for the US to drop the bombs on Japan?
There is no way to be sure that the actions of the United States in using atomic weapons were 'right'. The only real justification of the Hiroshima bomb was the unwillingness of Japan to surrender without invasion of the home islands, which would have resulted in millions of causalities on both sides. The Nagasaki bomb was unneeded, as Japan was already suing for peace. The U. S. military just wanted to see if it would work.
Japan was trying to develop weapons which could reach the US. balloon carrying fire bombs did reach the US but those didn't do much. The real deal was that Germany was trying to develop an atomic bomb but the US beat them. We don't have proof that Japan were trying to develop one. August 6 and 9 1945, Japan suffered the pain of the nuclear bombs.