What brought an end to war with Japan during world war 2 was the us justified in the this action?

In the final days of the Second World War, on Aug. 6 and 9, 1945, the U. S. dropped atomic bombs on Hiroshima and Nagasaki. Despite U. S. claims to the contrary, these actions were neither justified nor decisive in Japan's surrender ... The First World War, "the war to end all wars" ended in 1918.