A look back, from 50 years later, at the political and military circumstances and events leading up to the atomic bombing of Nagasaki on August 9 1945.

To compel Japan's unconditional surrender, President Truman threatened a "rain of ruin" culminating in the bombing of Nagasaki on August 9th 1945. Rain of ruin investigates the key political and military motivations for the atomic bombings, especially the Nagasaki bombing. Did Japan finally surrender because of the atomic bombs or were there other reasons? Was the bombs true aim to make an impression on Stalin? And why did the Soviet Union enter the Pacific War on the very date Nagasaki was bombed. This documentary reveals the bombing to be a more complex historical event than previously believed.