The new Oppenheimer movie has everyone asking questions about the atomic bombs dropped on Japan in 1945 - were two bombs necessary? Would the war have ended without it? Was there an ulterior motive? Would the Americans have dropped a third if they had it?

To answer some of the questions and more, Professor Paul Poast joined our sister podcast, Dan Snow's History Hit. Paul, from the Department of Political Science at the University of Chicago, explains how the decision to drop the bombs was really made, what would have happened if they hadn't and reveals that the Manhattan Project was actually more about impressing Stalin than destroying Japan.

Produced by Mariana Des Forges and edited by Dougal Patmore.

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