Operation Downfall

Operation Downfall, the planned invasion of the Japanese main islands. This was supposed to occur begin in October of 1945. The operation was called due to the Japanese surrender in August. I was wondering what effects might it have if the Japanese didn't surrender for what ever reason; the emperor was stubborn, the war staff performed a coup, or what ever.

How long would it have taken to defeat and occupy Japan if Downfall had to be executed?

I few questions I had about this. The Russians managed to invade the Kuril Islands and occupy them before the Japanese surrendered, and there is still a dispute over those Islands today. I guess the biggest question here is, how much of Japan could the soviets take before Japan was completely taken by the Allies? Would Japan be split up into occupation zones like Germany was, or would it be split into communist and democratic like Korea was?
 
I had a thread about this a couple of months ago...

Anyway, the invasion would have been a blood bath, considering that the Japanese had thousand of aircraft saved for just such an occasion. They would have dove upon troop transports and other easy targets packed with soldiers. I'm not fully convinced the invasion would have been successful.
 
How long would it have taken to defeat and occupy Japan if Downfall had to be executed?

Presuming there's liberal use of Atomic bombs, possibly the summer of 1946 considering due to weather conditions it couldn't be launched in late 1945.

I few questions I had about this. The Russians managed to invade the Kuril Islands and occupy them before the Japanese surrendered, and there is still a dispute over those Islands today. I guess the biggest question here is, how much of Japan could the soviets take before Japan was completely taken by the Allies? Would Japan be split up into occupation zones like Germany was, or would it be split into communist and democratic like Korea was?

The Soviets will likely invade and occupy Hokkaido but probably not get onto northern Honshu. The portion of Japan that was taken by America will be occupied by America and likewise with the Soviets. And afterwards it will likely become a Korea analouge but with no war.
 

Markus

Banned
I guess the biggest question here is, how much of Japan could the soviets take before Japan was completely taken by the Allies? Would Japan be split up into occupation zones like Germany was, or would it be split into communist and democratic like Korea was?

At least the Kurils and Hokkaido. Hokkaido was defended by too few troops(2*division,1*brigade) that were also concentrated in the wrong place, preparing for a US invasion. And given the short distance to Honshu probably a part of that island too, if the war had draged on into 1946.
 
If Japan was divided into communist and democratic like korea, could the following deal be done. The Americans trade southern korea for the northern Japan, creating a fully communist Korea, and a fully democratic Japan.
 
Considering that a typhoon his Okinawa in OCtober of 1945, that alone would have delayed the invasion for it would have ravaged the ships massing off the island. It would have also encouraged the Japanese for the typhoon, once again, muddled the invader.
 

CalBear

Moderator
Donor
Monthly Donor
Hokkaido was meat on the table for the Red Army. They wouldn't have had it as easy as the number suggest, mostly because they lacked the specialized amphibious shipping. I would actually expect the Soviets to lose more men by drowning than by any other single reason.

The entire concept of Downfall was undergoing serious revision as the day approached. The Intel was starting to make Kyushu look REAL unattractive. There is a fair chance, especially with the October typhoon, that the invasion might have been postponed until Spring of 1946. If that had happened you might well have seen a direct strike to Honshu, leaving the IJN and IJA stuck on the wrong Island without the fuel to move to the Kwanto Plain and contest the field. There is also a decent chance that, even without the Bomb, that by Spring of '46, the Japanese might have surrendered.
 
Assuming that Little Boy and Fat Man were dropped successfully, I can't see any way that we can reach a scenario where even Olympic is launched. Another poster mentioned dropping more A-bombs; so if the Americans continued to do this, how long would it be before they drop one on Tokyo? It doesn't matter how stubborn the Emperor is if he's dead.
On a side note, I always wondered what would have happened if they had dropped little boy on the top of Mount Fuji as a demo of the bomb's power?
 
Gents,

There's a Downfall thread every quarter or so seemingly. The Search function should pull up one from earlier this year that contains all the answers IBDK is asking for.

To cover a few high points:

- In the OTL, it was becoming very apparent that Downfall was not going to be launched as planned. King and Nimitz had only signed off on preparations for Downfall during the June JCS meeting. Since then and especially given the growing intel picture of what awaited the landings on Kyushu, their concerns had only multiplied and others, like Marshall and Arnold, had swung round to King's and Nimitz's opinion.

The only JCS member who still wanted Downfall to go ahead unchanged was MacArthur and that was because he didn't believe the intel.

The Downfall we see in the planning documents was not going to happen.

- The October '45 typhoon is blown out of all proportion, no pun intended. The US' demobilization had a huge effect on the limited warning about the typhoon and it's destructiveness. The US meteorological assets in western Pacific and Asia had been all but shutdown. The extent of the damage suffered was strongly linked to the lack of personnel required to move, secure, and other prepare both the invasion fleet and Okinawa for the storm.

With the war still on and with the lessons of Halsey's Typhoon still fresh in everyone's minds, the US would be on top of the storm's track and would not risk typhoon damage to an assembled invasion fleet. There would be enough men on hand to move, secure, and otherwise prepare both the fleet and Okinawa for the storm.


Bill
 
I never knew a Typhoon was in the area during the scheduled invasion time... the divine wind almost saves Japan again. :p
 
Top