Plausibility Check: Japan divided between US and USSR

[MrNumbahOne]

I had what I though would be an interesting idea for a TL. With a POD of the Manhattan Project never coming to fruition, how likely would it be for Operation Downfall to end up involving a secondary invasion by Soviet forces? Is it more likely to become split between East and West or South and North? There weren't any actual amphibious invasions planned on Japan's Western coast but that'd also be very awkwardly divided.

I appreciate any input.

 

[ObssesedNuker]

I had what I though would be an interesting idea for a TL. With a POD of the Manhattan Project never coming to fruition, how likely would it be for Operation Downfall to end up involving a secondary invasion by Soviet forces.

Practically guaranteed. The plans and assets were already in place by mid-August, Stalin just needed to give the go.

Chances of success? Probably high. The Japanese had very little understanding of Soviet amphibious assault doctrine at this time, as the Kuriles and North Korean landings demonstrated, not to mention the whole detail of their forces being in the wrong place but something could still go wrong.

Terms of division? North/South definitely. The bigger question is whether the Soviet zone would stop with Hokkaido or if they are able to carry out a second invasion into Honshu. The logistics there are questionable and it would require a significant pause even if feasible.

 

[Saphroneth]

An Ezo People's Republic?

 

[MrNumbahOne]

The bigger question is whether the Soviet zone would stop with Hokkaido or if they are able to carry out a second invasion into Honshu. The logistics there are questionable and it would require a significant pause even if feasible.

Question Barrage: What are the chances the Stalin would delve farther into Honshu? How far could the Americans have encroached into Honshu before their logistical pause was over? And would Stalin be content with the sparesly populated Hokkaido or try to expand? How densely populated is Northern Honshu?

And, out of curiousity, what exactly was the Soviet amphibious doctrine? Wouldn't they be inexperienced with it because it's the first time in history that they had to pull this off.

 

[The Red]

Wouldn't they be inexperienced with it because it's the first time in history that they had to pull this off.

They had pulled off amphibious invasions of northern Korea, the Kuril Islands and in Sakhalin in mid-August.

 

[Dan1988]

Question Barrage: What are the chances the Stalin would delve farther into Honshu? How far could the Americans have encroached into Honshu before their logistical pause was over? And would Stalin be content with the sparesly populated Hokkaido or try to expand? How densely populated is Northern Honshu?

To me, the only area of Honshû that the USSR would go for would be the Tôhoku region; maybe even Nîgata prefecture. What happens to it is anyone's guess; ideally, it would be a mix of Stalinism and Titoism together (which would be interesting to see, even if much of its economy would in practice be similar to an ordinary SSR, like Mongolia during its Communist period).

 

[ObssesedNuker]

What are the chances the Stalin would delve farther into Honshu?

Until Hokkaido is secured, any designs Stalin had on Honshu would be entirely speculative and not worth planning for, so there are probably no records. So the simple answer is: we don't know.

Of course, given how scared the Japanese were of Soviets actually making it onto Japan, a Soviet seizure of Hokkaido would probably be what prompts Japan to surrender, instead of the A-Bomb.

How far could the Americans have encroached into Honshu before their logistical pause was over?

That depends entirely on how events develop after August of '45, aside from the Soviet invasion. Do the Japanese surrender in response to the Soviet invasion? Do they surrender in response to oncoming famines? Do they surrender during the oncoming famines? Do the Japanese ever surrender at all or do they go down fighting? Do the Americans go through with Olympic? How well/badly does Olympic go? Does the famines and destruction of infrastructure lead to Japanese society collapsing into chaos completely?

There are many, many unknowns here.

And, out of curiousity, what exactly was the Soviet amphibious doctrine? Wouldn't they be inexperienced with it because it's the first time in history that they had to pull this off.

I've posted on this subject before, have a link.

 

[Visigoethe]

I have seen this map used as what a Japan with multinational occupation zones would look like. I could see The British and American zones merging together and The Soviet zone turning into it's own communist state. But I wonder what would happen to The Chinese Zone, Post War.

Note: I have not been able to find an actual source for the map so you should use with your own discretion.

 

[ObssesedNuker]

I really doubt there would be either a Chinese or a British zone, for the simple reason that there are not going to be Chinese or British troops involved in the invasion.

 

[David T]

Practically guaranteed. The plans and assets were already in place by mid-August, Stalin just needed to give the go.

Chances of success? Probably high. The Japanese had very little understanding of Soviet amphibious assault doctrine at this time, as the Kuriles and North Korean landings demonstrated, not to mention the whole detail of their forces being in the wrong place but something could still go wrong.

Terms of division? North/South definitely. The bigger question is whether the Soviet zone would stop with Hokkaido or if they are able to carry out a second invasion into Honshu. The logistics there are questionable and it would require a significant pause even if feasible.

Doug Muir had a post about this some years ago in soc.history.what-if:

https://groups.google.com/d/msg/soc.history.what-if/dZ5YlCyUuuo/DBQXF9ypq2QJ (he had a similar post here at https://www.alternatehistory.com/discussion/showpost.php?p=3875365&postcount=19)


***

Just to nail this one down ('cause it does keep popping up...)

1) Stalin asked Zhukov how many men he'd need to invade Hokkaido. "Two
armies," Zhukov replied. That's armies -- not divisions, armies. Don't know
how many divisions in a Soviet army but I'm guessing that's at least a couple
of hundred thousand men.

Both Zhukov and Vassilevsky hated the idea of invading the home islands.

2) In August '45, Soviets launched exactly one (1) amphibious assault. This
was against Shumshun, in the Kuriles. This islands was held by lightly armed
reserve troops without artillery or air support. Soviets took 1500 casualties
(to 1000 Japanese) in two days of fighting. Both sides then called a truce,
which turned into a Japanese surrender a few days later, since this battle
took place in mid-August.

Other Kuriles were occupied peacefully in late August and early September,
after Japan had surrendered.

3) Soviet sealift capability in this theater is hinted at in the description
of the fighting on Shumshun. Ships broke down because of lack of lubricant,
and Soviet troops were reduced to living on dry biscuit. This after six
months of preparation. Not exactly Overlord.

Soviets were using minesweepers to land occupation troops in the northern
Kuriles, which reinforces the idea that they didn't have too many landing
craft on hand.

4) Soviets invaded south Sakhalin after six months of preparation with clear
numerical superiority, total command of the air, and overwhelming superiority
in armor and artillery. In this, they were following much the same
sledge-hammer model as in their attack on the Kwantung Army in Manchuria.
However, the results were not the same. While the Kwantung Army more or less
collapsed, Japanese resistance on Sakhalin was "stubborn" and "savage" (Soviet
description... and keep in mind that these troops were veterans of combat
against the Germans, thus not likely to use such words lightly).

I have found no record of Red Army casualties, but note that it took nearly
three weeks of fighting -- August 9 to August 28 -- for the Red Army to
capture Otomori, near the southern end of the island. Apparently there was
still heavy fighting on Sakhalin two weeks after the Japanese surrender!

5) Soviet plans for landings in Hokkaido were limited in scope; they were
intended to seize beachheads and a modest amount of territory in order to
secure Stalin a voice in the occupation of Japan. AFAICT, the Soviets never
had any serious plan -- comparable to the American Olympic or Coronet -- to
actually conquer Hokkaido.

Note that Stalin tried to gain this at the bargaining table, asking Truman to
grant him an occupation zone in northern Hokkaido "in accord with the spirit
of Yalta"... a proposal that Truman firmly rejected.

So, to summarize... Soviets in Hokkaido, just maybe, though I doubt it.
Soviets in Honshu, no.

 

[ObssesedNuker]

1) Stalin asked Zhukov how many men he'd need to invade Hokkaido. "Two armies," Zhukov replied. That's armies -- not divisions, armies.

First, I never heard that Zhukov actually give an estimate, so I'm going to need a source. The Soviet assault echelon was going to be a corps (so three divisions) inserted over the space of a week. The landing spot chosen was completely undefended and once ashore the Japanese have no capability to repel the Soviets on Hokkaido.

And with only 2.5 Japanese divisions on the entire island, the Soviets would probably need just a single army at absolute maximum to clear the island, at which point it is as good as theirs.

Both Zhukov and Vassilevsky hated the idea of invading the home islands.

They had objections, but hated is a strong word.

In August '45, Soviets launched exactly one (1) amphibious assault. This was against Shumshun, in the Kuriles.

Factually untrue. The Soviets launched three separate amphibious assaults in mid-August: the Kuriles, North Korea, and Southern Sakhalin. All three amphibious operations were near simultaneous, meaning they all used assets independent of each other. Furthermore, unlike on the Kuriles, the Japanese do not have anywhere near sufficient troop strength to defend every inch of invadable territory on Hokkaido. Finally, despite all the difficulty the Soviets experienced in landing on the Kuriles, the point remains that the Soviets were able to establish their beachhead and the Japanese were unable to dislodge them.

This pretty much goes for the next bunch of his comments as well.

Soviet plans for landings in Hokkaido were limited in scope; they were intended to seize beachheads and a modest amount of territory in order to secure Stalin a voice in the occupation of Japan. AFAICT, the Soviets never had any serious plan -- comparable to the American Olympic or Coronet -- to actually conquer Hokkaido.

Completely ignores that once the soviets defeat the Garrison on Hokkaido, the island is de-facto conquered. All Japanese ferries between it and the rest of the home islands had already been destroyed, so they have no capability to bring in any further forces.

Note that Stalin tried to gain this at the bargaining table, asking Truman to grant him an occupation zone in northern Hokkaido "in accord with the spirit of Yalta"... a proposal that Truman firmly rejected.

Technically, it wasn't Stalin asking Truman... it was Molotov on the behalf of Stalin asking Harriman on the behalf of Truman after the Japanese had surrendered.

If Japan hasn't surrendered, Stalin's going to go ahead and land at which point Truman is presented with a fait accompli.

So, to summarize... Soviets in Hokkaido, just maybe, though I doubt it. Soviets in Honshu, no.

Depends on how long the war drags out after the Soviets land on Hokkaido.

 

[DevonPasty]

I really doubt there would be either a Chinese or a British zone, for the simple reason that there are not going to be Chinese or British troops involved in the invasion.

I dunno. My grandad was pretty convinced his unit would've been called up to join an assault on Japan if they hadn't surrendered. He was a commander of an artillery unit so I don't know if there were plans for British artillery to join an assault on Japan or whether it was just speculation.

He was sent out to Singapore I think it was, somewhere out East following the German surrender for a while (can't remember how long) so it doesn't seem impossible that there would have been a British involvement.

 

[The Red]

I dunno. My grandad was pretty convinced his unit would've been called up to join an assault on Japan if they hadn't surrendered. He was a commander of an artillery unit so I don't know if there were plans for British artillery to join an assault on Japan or whether it was just speculation.

He was sent out to Singapore I think it was, somewhere out East following the German surrender for a while (can't remember how long) so it doesn't seem impossible that there would have been a British involvement.

Perhaps he was going to take part in Operation Zipper?

It's likely that Commonwealth troops would have taken part in Coronet, which had been agreed shortly before Japan's surrender.

 

[David T]

First, I never heard that Zhukov actually give an estimate, so I'm going to need a source.

William Taubman writes in *Khrushchev: The Man and His Era*, "Should the Red Army invade Hokkaido, an effort that Zhukov estimated would require four full-scale armies?" http://books.google.com/books?id=8n7zYmshBNgC&pg=PA332 OTOH, Tsuyoshi Hasegawa in *Racing the Enemy: Stalin, Truman, and the Surrender of Japan* writes "Stalin asked Zhukov how many additional divisions would be needed to carry out this operation. Zhukov answered at least four." http://books.google.com/books?id=iPju1MrqgU4C&pg=PA116

Obviously, there is a big difference between four divisions and four "full-scale armies." Both Taubman and Hasegawa cite Boris Slavinsky, but his article in the Japan Forum on "Soviet Occupation of the Kurile Islands and the Plans for the Capture of Northern Hokkaido" in the April 1993 *Japan Forum* seems to be unavailable online.

 

[Roisterer]

Does this mean we see a communist "North Tokyo" enclave?

Regards

R

 

[The Red]

OTOH, Tsuyoshi Hasegawa in *Racing the Enemy: Stalin, Truman, and the Surrender of Japan* writes "Stalin asked Zhukov how many additional divisions would be needed to carry out this operation. Zhukov answered at least four." http://books.google.com/books?id=iPju1MrqgU4C&pg=PA116

That seems far more reasonable, though that could simply mean to police the island. Hokkaido was far less populous than Kanto or Kyushu but it's still a big ask for three divisions to hold it alone.

 

[Tyr]

It's a bit totally un common trope in Fringe Japanese fiction. I've often mused with trying such a tl myself. It is pretty possible and could be very interesting. Sadly however the main interesting parts would likely be in culture which is hard to show in tl format and replicating a country's culture, even a theoretical country's, as one foreign individual is tough.


I love the idea of a split tokyo. I think it's vital for such a scenario to play out to its fullest. The border perhaps right through the imperial palace. From there saitama is in the north and the border naturally takes in kanto, Niigata is a toss up, perhaps split too. This would give a fairly nice and Germany analogous balance with most of kanto in the north and kinki in the south


Re Chinese and British zones- there was iotl, I don't see why not here. Even if the us does all the work (they would do most but I'm not sure on all) it would appreciate the help in occupying, and the other nations would like some credit for the victory.



As to how communist japan would look- well... It depends how tight a reign the soviets keep. But essentially North Korea is an imperial japan remnant state. It could be argued that japan itself given such an opportunity would be like NK on crack. Then again japan did have far more of an established communist presence than Korea did. I'm afraid I don't know much at all about their leanings at the time

 

[The Red]

It's a bit totally un common trope in Fringe Japanese fiction. I've often mused with trying such a tl myself. It is pretty possible and could be very interesting. Sadly however the main interesting parts would likely be in culture which is hard to show in tl format and replicating a country's culture, even a theoretical country's, as one foreign individual is tough.

I'm always open to ideas, if you'd like to share?