Olympic
X-Day was the date 01 Nov 1945 of planned invasion of Japan, Operation OLYMPIC/MAJESTIC.
Operational Downfall, or the American invasion of the Japanese home islands was planned sometime during October of 1945. The operation became moot after the total capitulation of Japan after the nuclear strikes on Hiroshima and Nagasaki.
See "The Planned Invasion of Japan: Bibliography of works by D. M. Giangreco" at http://www.waszak.com/giangreco_bibliography.htm .
It provided an alternative to the planned invasion of japan which would have cost thousands of lifes
The invasion of Japan was planned as two distinct phases: #1. Operation OLYMPIC -- The original invasion of the Japanese island of Kyushu -- schuduled for November of 1945. #2.Operation CORONET -- The follow-up invasion of the northern Kanto Plain area of Japan -- scheduled for March of 1946. I feel I can confidently state that Marines, fresh from Okinawa, would NOT have been aware of EITHER code word. That was all very hush-hush, top, top secret stuff at the time. Only the very top brass in the Marine corps would have been aware of some or all of the details concerning the invasion of Japan or its code words. My WWII outfit -- fresh from Okinawa -- was scheduled for the eventual November invasion and we had never heard the words. In fact I didn't know anything about them until long after the war, while reading about them in a book.
Okinawa was the island that the Americans used as a basis for casualities and losses to human life for the planned invasion of the main islands of Japan. When the island was taken, the projected losses ran to over a million American lives which was deemed too costly for an invasion of mainland Japan so an alternative way to defeat Japan had to be found which resulted in the two atomic bombs being dropped on Hiroshima and then Nagasaki in August 1945. This effectively ended the Second World War with not a single American being killed by invading Japan.
Estimates vary greatly as to the casualties to American Forces for Operation OLYMPIC, the invasion of Kyushu, planned for Nov. 1, 1945 & Operation CORONET, the invasion of Honshu, planned for Mar. 1, 1946. I respectfully suggest the following book that covers the casualty estimates in detail. Codename: DOWNFALL by Thomas B. Allen & Norman Polmar New York Simon & Schuster 1995 ISBN: 0-684-80406-9 Richard V. Horrell WW 2 Connections.com 250.000 to 500,000 would be a safe guess including my dad and uncles. so i am glad that we dropped the A bomb on japan.
The Atomic Bomb
During the early part of World War Two, the distance of Japan was so far from the US that the Pacific Ocean protected Japan from invasion. The Chinese had no chance to invade Japan and the USSR had an agreement not to engage in combat until the very last days before Japan's surrender.
tojo
Japan's invasion of China and its attack on the US at Pearl Harbor. Italy's invasion of Ethipoia. Germany's Invasion of Poland and Russia.
the decision to drop the bombs caused the Japanese surrender. This prevented massive casualties on both sides in the Operation Downfall invasion of Japan and from an otherwise prolonged war.