There has long been a scholarly debate about whether it was necessary for the United States to use atomic weapons to bring World War II to an end. Traditionalists say yes: If not for Fat Man and Little Boy, Japan would have fought to the last man. But revisionists argue that by August of 1945: (a) Japan’s situation was catastrophically hopeless; (b) they knew it and were ready to surrender; and (c) thanks to decoded Japanese diplomatic messages, Harry Truman and other American leaders knew they were ready. A Japanese surrender could have been negotiated in fairly short order with or without the destruction of Hiroshima and Nagasaki.
Why Did World War II End? | Mother Jones