Soviets invade Hokkaido?

Just how good of a chance did the Soviets have of invading Hokkaido if Japan hadn't surrendered when they did?

 

Not too bad a chance actually, we (America) had supplied them with a great number of amphibious landing craft and ships in June and July of 1945. Trained the Red Banner Fleet sailors in their use, and turned them over to Soviet control.

They had their own version of Marines, the Naval Infantry, and they were excellent fighters. The fact of the matter is the Soviets didn't stop fighting on Shakalin Island until well after the August acceptance of the Potsdam Declaration. They were still engaged in open combat near the end of the month as they didn't want the "lines" to be drawn at the moment of Japan's surrender. They continued on until they had taken the entire Island which they hold today.

The Red Army forces also completed the occupation of the Kuriles at this time, even though the "fighting" was supposed to be over. The last B-29 missions to the northern most part of Japan happened the night before Hirohito's announcement, and it isn't out of the realm of possibility that this was done to send a not so subtle message to our Soviet allies. "We can reach your troops with our bombers if you don't stay off of Hokkaido". And now they knew we had the atomics. They didn't know how many, but they knew we had them. I think the second drop was a surprise, and ramped up the thought that we had more than the two spares we did have at the moment.

I've got a great list of the amphibious ships and boats we had transferred to the Red Banner Pacific Fleet if you would like them?

 

The Red Army and the Naval Infantry could also have proceeded across from Shakalin Island onto the norther shore of Hokkaido with little if any resistance from the Japanese. If the atomics hadn't worked, they may well have. Let’s say, for argument’s sake that the "atomics" failed to function as designed, or failed to bring the Imperial Japanese to the point of surrender; America may well have welcomed the Soviet Red Banner Fleet and its armed forces invasion of northern Japan.

That may have been why America recognized the lack of ships in the Red Banner Fleet in the Pacific, and supplied them with specialty landing ships, and trained the crews to use them. By August of 1945, the Soviet Pacific Fleet only had these as indigenous warships; 2 cruisers (1 the flagship), 10 destroyers, 2 torpedo boats, 19 patrol boats, 78 submarines, 10 mine-layers, 52 mine-sweepers, 49 "MO" (light attack) boats, and 204 motor torpedo boats of their own design and construction.

Against this Red Fleet, the Imperial Japanese had nothing left to speak of, thanks to the USN and the USAAF. Recognizing the weakness of the Red Banner Fleet in the east, in the spring of 1945; numerous LCIs, LCTs, and 28 Coast Guard frigates were transferred by the United States to the Soviet Union under lend-lease to suppliment their Pacific Fleet. And Soviet sailors were trained in the use of the ships in Cold Bay Alaska by US Coast Guard sailors. The USCG transferred the ships to the USSR, and the Red Banner was hoisted over all of them by late July of 1945 and they sailed for Mother Russia with their new Soviet crews. These ships and training in their use was in anticipation of perhaps the need for a Soviet invasion from the north while America and the UK forces launched their own from the south.

Here is a complete list of all US specialized "landing craft" supplied to the USSR under Lend-Lease from mid-’44 to July ’45; this list was supplied by "Tiornu" (Richard Worth) on another forum:

2 LCVPs: C-42116, C-42737
2 LCS(S)s: C-7653 (Mk 1), C-51393 (Mk 2)
2 LCM(3)s: C-29301, C-29309

54 LCM(3)s: LCM 786, LCM 787, LCM 793, LCM 850, LCM 851, LCM 857, LCM 858, LCM 859, LCM 860, LCM 861, LCM 862, LCM 863, LCM 864, LCM 866, LCM 867, LCM 868, LCM 869, LCM 870, LCM 871, LCM 872, LCM 873, LCM 874, LCM 875, LCM 876, LCM 877, LCM 878, LCM 879, LCM 880, LCM 881, LCM 46972, LCM 46973, LCM 46974, LCM 46975, LCM 46976, LCM 46977, LCM 46978, LCM 46980, LCM 46981, LCM 52410, LCM 52411, LCM 52412, LCM 52413, LCM 52421, LCM 52422, LCM 52423, LCM 52425, LCM 52426, LCM 52427, LCM 52428 (Three of these were lost in attacks in the Far East in 1945 flying the Red Banner.)

2 LCTs: LCT 1163, LCT 1176

15 LCT(6)s: TDS.1 (ex-LCT 1047), TDS.2 (ex-LCT 559), TDS.3 (ex-LCT 561), TDS.4 (ex-LCT 563), TDS.5 (ex-LCT 745), TDS.6 (ex-LCT 1015), TDS.7 (ex-LCT 1046), TDS.8 (ex-LCT 1442), TDS.9 (ex-LCT 1445), TDS.10 (ex-LCT 744), TDS.11 (ex-LCT 1434), TDS.12 (ex-LCT 1435), TDS.13 (ex-LCT 1436), TDS.14 (ex-LCT 1437), TDS.15 (ex-LCT 1438)

30 LCIs: DS.1 (ex-LCI(L) 526), DS.2 (ex-LCI(L) 527), DS.3 (ex-LCI(L) 551), DS.4 (ex-LCI(L) 554), DS.5 (ex-LCI(L) 557), DS.6 (ex-LCI(L) 666), DS.7 (ex-LCI(L) 671), DS.8 (ex-LCI(L) 672), DS.9 (ex-LCI(L) 945), DS.10 (ex-LCI(L) 946), DS.31 (ex-LCI(L) 584), DS.32 (ex-LCI(L) 585), DS.33 (ex-LCI(L) 586), DS.34 (ex-LCI(L) 587), DS.35 (ex-LCI(L) 590), DS.36 (ex-LCI(L) 591), DS.37 (ex-LCI(L) 592), DS.38 (ex-LCI(L) 593), DS.39 (ex-LCI(L) 665), DS.40 (ex-LCI(L) 667), DS.41 (ex-LCI(L) 668), DS.42 (ex-LCI(L) 675), DS.43 (ex-LCI(L) 943), DS.44 (ex-LCI(L) 949), DS.45 (ex-LCI(L) 950), DS.46 (ex-LCI(L) 521), DS.47 (ex-LCI(L) 522), DS.48 (ex-LCI(L) 523), DS.49 (ex-LCI(L) 524), DS.50 (ex-LCI(L) 525). (Four or five were war losses before the PTO was done).

Richard Worth, i.e. "Tiornu" is generally quite accurate when it comes to ships, names and numbers. Not a bad little flotilla of amphibious ships and boats n’est pas? America was "hedging its bets" as per the atomics, and the need for Downfall, both the Olympic and Coronet operations. It is fortunate for America that the atomics worked, and not just because the Soviets might have gained ground in northern Japan and created a north and south Japan like the east and west Germany, or the north and south Korea.

When Okinawa (the staging area for Olympic), was hit with Typhoon Louise in October of '45, fortunately it was by then nearly abandoned. Yet it still represented the largest loss of USN ships and US armed forces in history to a "natural event". If Japan had still been holding out, and keeping the Red Army at bay, a real "divine wind" would have again decimated their foes, hundreds more ships and men, just as it had centuries before against Kublai Khan. I wonder how much harder they would have fought after that? With that obvious "intervention by the Gods", the correctness of their place in the world, and the support of the Gods would have made a surrender impossible without complete genocide annihilation (in the words of Halsey), "..when we are done with them, Japanese will only be spoken in hell !".

I'll post a "run-down" of that typhoon losses if anybody wishes to see it.

 

I was actually quite curious about that, would it be much trouble?

 

Not much trouble, when it comes to weather that is a force many don't take into account when looking in from the outside using hindsight.

Weather could have been devastating to Operation Downfall in the PTO. Admiral Halsey, and the fleet under his command had already been "mauled" by two separate typhoons, so "typhoon season" was certainly taken into account in the planning for the invasion of the home islands of Japan. Downfall was going to be larger by far than the Overlord operation, and an estimated 550,000 American troops alone were slated to the landing effort itself, that is just "boots on the dirt" !

Fourteen combat divisions of American soldiers and marines were slated to land on Kyushu after an unprecedented Naval and aerial "softening up" for Operation Olympic on November first, 1945. This was designed to be after the "traditional end" of the typhoon season. This would be followed by Operation Coronet which would land twenty two more America combat divisions on the Tokyo plain (if necessary) on March first, 1946 well before the new typhoon season would begin. America knew better than to "fight nature", or they were learning like the Japanese who never fought "nature" in the Pacific.

And where were they assembling and preparing for the massive effort in the most concentrated group? On Okinawa.

There were slated to be nearly 4,000 army, navy, and marine aircraft that would be packed into the small island of Okinawa for Olympic alone, not counting the thousands of ships, large and small which would have been crowded in what was now Buckner Bay or around the tiny island. Typhoon Louise was an abnormality, an aberration, a fluke, a one in a million. Navy meteorologists predicted that the out of season storm would (after they recognized its existence), sweep northward, pass between Okinawa and Formosa, and die out in the East China sea. That is NOT what occurred.

The most devastating storm ever encountered by the US Navy began on the evening of October eighth, when the storm changed direction and abruptly veered to the east. Now there was insufficient warning to allow the ships remaining in the harbor to get under way in order to escape the typhoon. By mid-morning of the ninth, torrential rains lashed by 80 mph winds, and rising 50 foot waves caused the 150,000 men remaining on the island to seek shelter and "hunker down" in the caves/trenches only recently abandoned by the enemy. By early afternoon their "tent city" was blown away, as were the most of the food supplies by the now 100 mph winds. By late afternoon the winds topped out at 150 mph, and waves were at 60 feet in the bay. The storm raged over the island for nearly twenty hours, and then slowly headed out to sea. Then as if it were a late, but still avenging "divine wind", it doubled back, and two days later howled in from the ocean to hit the island again. This "attack" seemed to deflate Louise, and she quietly died off a day later in the Sea of Japan and the bodies began to wash ashore.

The toll on the relatively small group of ships remaining after Downfall had been canceled was staggering. Almost 270 ships were sunk, grounded or damaged beyond repair. Fifty-three of the ships in too bad a state to be restored to duty were duly decommissioned, stripped and abandoned on site. Out of 90 ships which needed major repair the Navy decided only 10 were even worthy of salvage, and so the remaining 80 were simply scuttled or scrapped. General Joseph Stillwell, the 10th Army Commander, asked for immediate plans to evacuate all hospital cases from the island by air. All the aircraft had been destroyed, all power was gone, communications and supplies were nonexistent. The harbor facilities were useless. Casualties were low all things considered, like the extreme violence of the storm. This was very probably due to the active and well directed efforts of all hands in assisting one another, particularly in evacuation of grounded and sinking ships. By mid-October, reports had been sifted and it was found that there were 36 dead and 47 missing, with approximately 100 receiving fairly serious injuries.

Surprisingly, few people make the connection that an American invasion fleet of thousands (not hundreds) of ships, planes and landing craft, and a half million men would have been in that exact place at that exact time, poised to strike Japan, when this typhoon enveloped Okinawa and its surrounding seas IN REALITY. But thanks to the "atomics", the surrender documents had been signed just three weeks before Louise devastated Okinawa.

To add more irony to the picture, the area for assembling the forces to hit the Tokyo plain in the Coronet operations were to be in the Philippines, and when they would have been assembling, another typhoon hit that area in early 1946.

 

Another very informative post!

One question though, did the Japanese learn of this post war? If so were there any effects?

 

Are you sure the Soviets didn't know the US had more than two atomic bombs?

By August 1945, a prototype atomic bomb production line had been set up and was manufacturing one atomic bomb approximately every ten days. I believe the Soviet spies were still in place at that time, and it's entirely possible that they were in a position to at least be aware of the on-going production.

 

One hundred or so landing craft really isn't much of a fleet when one considers the thousands that would have been necessary for the projected Kyushu landings. Moreover, the landing craft supplied to the Soviets were not in very good shape after having been used for training and other miscellaneous uses. The certainty of heavy losses in an actual landing would have reduced the numbers of landing craft to the point that resupply and support of the landed troops would have quickly come into question.

I believe it was Richard Frank who wrote that the Soviets actually had tentative plans for a regimental size landing on Hokkaido. But this was abandoned for two reasons, one is as you suggest, subtle and not so subtle, hints by the US that a Soviet landing in the Japanese Home islands would NOT be welcome. The other was the Soviet realization that a regimental size landing, which was pretty much the maximum limit that could be supported by 100 landing craft, wouldn't have much chance against the numbers of defenders that could be brought to bear against an invasion of Hokkaido.

 

I believe the problem for the Soviets as per the number of "spares" was that their spies weren't in the loop as to the core production rates. I could be wrong there, but I also don't know how rapidly the like of Fuchs, Nunn, and Hall could get the data to the "powers that be" back in Moscow.

I suspect that there were more "believed" to be held in stockpile than the two plutonium bombs which actually existed (implosion type), and four uranium bombs (gun-type). But even that knowledge, six in stockpile would be a deterent to an invasion on the northern shores of Hokkaido after the B-29s had made their "last mission" to the oil refineries and tanks farms of that island. America was just "hitting its stride" as per production times, and there surely would have been many, many more needed if NEEDED. Fortunately the Imperial Japanese accepted their defeat and made them un-necessary when their enemies had apparently captured the power of their Sun Goddess and unleashed it on the people of The Land of the Rising Son, ruled by the Son of the Sun. Now the heavenly mandate of the Sun Goddess was NOT in their favor. And a great many Japanese were very religious and true believers in Shitoism.

Again, just guesses on my part.

 

I guess that this interesting thread has gone as far as it could for now. If anyone has more to offer, get this thread back on track by all means.

The idea of a Soviet amphibious invasion of Hokkaido makes me think why didn't the US pursue an avenue of invasion via the North Pacific instead of pushing up from South and Southwest Pacific. There were many islands that we took that could have been neutralized and left to wither on the vine (Tarawa and Peleliu comes to mind). How strongly fortified were the Kuriles and the southern portion of Sakhalin from 1943 on? Does anyone have access to those numbers? I know that operating from the Aleutions would be a daunting task, but could a strong diversionary campaign from the south or southwest to divert attention away from the drive from the north be feasible? This theory has been on my mind for some time now, and any help would be most welcome.

I really don't want to offer this as a "what if," but a "why not" or a "how come" would be better.

 

Staging an invasion of the scale anticipated would be nigh impossible from the north for the Americans, plus the Red Army was already there, or at least moving south of their border into the Japanese section wouldn't have been too difficult, but add in a huge Anglo/American presence and it may have been.

Stalin and the Soviets were sort-of "bribed" into the Far East by FDR in exchange for agreeing to join the UN post-war. He (FDR) also indicated at the Yalta Conferrence that he wouldn't object to their reclaiming the territory on Sakhalin they had surrendered in the 1905 Treaty of Portsmouth (engineered by his distant cousin TR).

Don’t forget that whole area (north of Japan home islands proper) has been in dispute since about the 1600s when the Russian Tzarist expansion began toward the east, in Russian sources Sakhalin and the Kuril islands are mentioned for the first time in 1646, the earliest detailed information about them was provided by the explorer Vladimir Atlasov in 1697. In the 18th and early 19th centuries, the Kuriles were explored by Danila Antsiferov, I.Kozyrevsky, Ivan Yevreinov, Fyodor Luzhin, Martin Shpanberg, Adam Johann von Krusenstern and Vasily Golovnin.

The fact that the islands were inhabited by the indigenous Ainu, and used occasionally by the Japanese fishing groups was of little import "in the grand scheme of things" geopolitically considereing the Japanese Empire was a new comer. Skip backward to this:

Time table of Sakhalin

From there the Japanese "claim" becomes a bit more defensible. But after the 1904-05 Russo-Japanese war the Kuriles and Sakhalin were split with the Russians (later Soviets) occupying the northern half and the Japanese the southern. That is why it was so easy for the Red Army to advance to the south at war's end, they had a port and half Sakalin island already under their control.

Here is a link to "who ran what" for centuries by map:

Secret of Sakhalin Island (Karafuto)

I seem to recall that about 600,000 Japanese were taken prisoner by the Soviets in those "northern islands", mostly soldiers and sailors, only about 10% of them were returned to Japan over the years from camps in Siberia. I don’t know the ratio of soldiers to civilians however. As I mentioned at the beginning of this post, the Soviets had been promised the southern portion of Sakhalin Island to be returned to them (which they lost in 1905), and Kuriles (which they lost in the 1875 [?] Treaty of St. Petersburg).

On August 14, 1945, Japan officially surrendered to the Allies by accepting the Potsdam Declaration, this included the Soviet Union, which had declared war on them a week before. At this time neither southern Sakhalin nor the Kuriles had been occupied by the Soviets.

President Harry Truman, who was decidedly less friendly to the Soviet Union than Roosevelt had been, stated that; " although the Soviets could occupy the Kuriles, they remained Japanese territory and their ultimate status would be determined by a future peace treaty." Truman also strongly rejected Soviet requests for an occupation zone in Hokkaido.

After that Red Army commanders wasted little time in attacking southern Sakhalin and the Kuriles, the former on August 18 and the latter on August 23. On September 2, the Japanese Foreign Minister Mamoru signed the surrender documents on the deck of the USS Missouri in Tokyo Bay.

By that time, the occupation of the Kuriles extended to Shikotan island, and was completed three days later with the occupation of Habomai. The occupation of the Kuriles, especially the islands of Habomai, Shikotan, Kunashiri and Etorofu (the Northern Territories), which had been Japanese territory since 1855, proved to be a bitter pill for the Japanese to swallow, especially since they viewed August 14th as their surrender date.

At the 1951 Conference of San Francisco that should have settled the definitive frontier between two countries, it was not signed by the Soviet delegation (Korean War was going on). They refused to sign the final document, because the Soviets felt it didn't state clearly enough that south Sakhalin and Kuriles would become Soviet territories permanently.

I am not sure how that stands now that the Soviet Union is no more, but I would assume it still hasn't been settled between the new Russia and Japan.

 

IIRC, Stalin never considered the Atom Bomb to be a serious threat, so it's unlikely that this would be a major factor in their planning. The overall threat of following up WWII with an immediate WWIII would be more of a factor than any individual weapon.

It's highly doubtful that the US would use atom bombs against Russia to defend Japan.

 

Stalin's mild reaction to being told of the atomics by Truman has been revised since the foreknowledge he had through the spies in MED came to light. When Truman informed him of them he thought Stalin didn't understand their full potential, but Stalin was aware of them (probably before Truman actually). It was the speed with which we advanced from the test at Alamagordo to two bombs being dropped which caught him unaware.

He advanced his declaration of war by about two weeks so that it fell in between the first and second bombs, but originally it was to have been at a later date. I still hold that those "final missions" of the B-29s to the Hokkaido refineries on the night of August 13/14th were a not too subtle message to Stalin that we could reach that area.

Knowing the atomics worked, and that our B-29s could reach northern Hokkaido must have been a sobering event for Stalin's plans, if he had any for an occupation zone on the Japanese home island. Stalin also announced that he would withdraw from northern Iran as soon as the war was over, he did. He announced he would withdraw from norther Korea after the war, and he did. I think the existance of the atomics may have come into play here, he certainly didn't observe all his promises made to the west, but those he did.

 

Absolutely correct. When Stalin was told of the new weapon it was almost as if he had shrugged it off. The allies telling him thought he either did not fully appreciate what they were hinting at or simply did not care. Little did they know...

 

Here is a fun link to the "atomic spies" page at PBS. It wasn’t until about 1995 that all the Venona cables were released, and the full extent of Soviet espionage in the Manhattan Project came to light.

See:

NOVA Online | Secrets, Lies, and Atomic Spies | Read Venona Intercepts

They aren't all in that little section, but it gives one an idea of how early on the Soviets were receiving information on the atomic project. I cannot recall where I heard this next, or even the exact words, but I think it was in one of Truman's diary entries from the Potsdam meeting.

Stalin replied (when informed of the bombs) that he; "hoped they would be put to good use against the Japanese soon." (paraphrasing)

 

Getting a bit off track here, but this is connected with Stalin finding out about the 'new explosive" at Potsdam.

Here is one section which deals with Truman telling Stalin of the "bomb", although he carefully avoided the words "atomic or nuclear":

On July 24, after the end of a session at the Cecillenhof, Truman walked carefully around to Stalin, who had stood up and was preparing to leave the hall and told about the test explosion of a nuclear bomb. Truman did not use the word "nuclear" and simply related that the United States had just successfully tested a new weapon of great explosive power and that he wanted the Soviets to know this fact. Stalin did not appear very impressed and, indeed, gave Truman the feeling that he had not quite understood the purpose of the revelation. But indeed he had, for when he got back to his quarters, Molotov was heard to say to Stalin, "We 'II have to talk it over with Kurchatov and get him to speed things up" (Memoirs of Marshal Zhukov). Professor Igor Kurchatov was in charge of the Russian nuclear program, which, after a lapse because of the removal of laboratories from Moscow during the war, had quickly resumed. At Potsdam the President obviously did not know that Russian spies had penetrated the bomb project and that Stalin would have the bomb "secret" within weeks of Alamogordo. Actually the first Russian bomb, which was tested August 1949, was a copy of the American plutonium bomb. Truman proudly annotated the photograph of adjournment of the July 24 session, "This is the place I told Stalin about the Atom Bomb, which was exploded July 6, 1945 in New Mexico. He didn't realize what I was talking about. (emphasis mine)

See:

Chapter 5: From the President's Diary, July 17, 18, and 25, Truman and the Bomb, a Documentary History

There also great links to Truman’s own diary input from Potsdam on that page.

 

I was theorizing about a US campaign in the North Pacific earlier than 1945, while the Soviets were still busy with the Germans, but probably that proposal would probably be just as much of a stretch as well. Thanks for the in-depth and informative response anyway!

 

I think the US gave up any idea of invading Japan through the northern route (Aleutians) because of the miserable weather, stormy seas that were common and the lack of any suitable place to stage from. And that was from experience gained in 1943.