Atomic bombs were first used in ww2. The bomb was dropped twice on Japan. It ended ww2. This was last time atomic bomb was used. Estimates say between 100000 to 200000 died.
As the war Europe was at an end. The war in the Pacific was ending. Japan was pushed back to mainland. The task was to invade Japan. The human cost would have been high.
The Japanese civilian people were ready to fight. The Japanese strengthened there defences. The lack of raw materials was an issue for Japan. Allies were bombing Japan from 1944.