SGS Operation Downfall

We all know that the atomic bombings of Hiroshima and Nagasaki in August 1945 hastened Japan’s surrender at the end of World War II. But what would have happened if the Manhattan Project had failed, or if there had been such delays that the bombs could not be built in time?

Operation Downfall was the code name for the Allied plan to invade the Japanese Home Islands. The operation consisted of two parts: Operation Olympic and Operation Coronet. Operation Olympic was to begin in November 1945 and was to capture the southern third of the southernmost main Japanese island of Kyushu, with the recently captured island of Okinawa to be used as a staging area. Operation Coronet, a planned invasion of the Kanto Plain, near Tokyo, on the main Japanese island of Honshu, would follow in early 1946. Air bases on Kyushu captured in Operation Olympic, and possibly others on the nearby island of Shikoku, would have provided ground air support for Operation Coronet. If Operation Downfall had taken place, it would have been the largest amphibious operation in history.

The geography of Japan made this invasion plan obvious to the Japanese themselves; they were able to accurately predict the Allied invasion plans and adjust their defensive plan, Operation Ketsugo, accordingly. The Japanese planned a total defense of Kyushu, with a small reserve force for subsequent defensive operations. Casualty estimates varied widely, but were extremely high. Depending on how much Japanese civilians resisted the invasion, Allied casualties were in the millions.

This game will allow you to experience two landings and a general amphibious assault on the Japanese home islands in 1945 and 1946.

The scale of the game is at the division level for land units, wings for air units. Naval forces are abstracted, and other special weapons such as Kamikaze or Midget submarines are represented by events or the play of battle cards. Each region is about 100 square miles in size, and a turn represents 1 week of real time.

Scenarios vary in length, from 10 to 27 turns. They offer you different starting options (more troops, more replacements, more air support, different starting positions, landing operations) that can change the historical balance and offer huge replay potential. The Soviet intervention in the operation planned against the northern island of Hokkaido is also included. Japanese domestic politics are also considered, as well as the role of the emperor and his defense against capture.