The Japanese had every chance to surrender after the first bomb was dropped, so why did they not surrender, well it was because they still thought that they could fight on. Now by dropping those bombs it brought WW2 to a much quicker end with far less bloodshed that would have happened if an invasion had taken place. Had the invasion taken place then the Allies could have been fighting every man woman and child in Japan. The Japanese army already had plans in place for this to be put into effect, also another thing to consider ids that the Japanese had plans to kill every POW that they could lay there hands on. I worked with a chap who was just out side Nagasaki when the bomb was dropped and he was being march to a death camp, and he was always thankful to the bomb and the Americans that dropped it.
LeEnfield Rides again