Operation Downfall

[Sanny]

If President Truman decided not to drop the bomb on Japan, Operation Downfall would have taken place and would have been the largest amphibious assault in human history. 30 Allied Divisions were needed to invade Japan whilst Japan dug in on the Southern island of Kyushu. It was estimated there would have been millions of casualties on both sides if this fight went down (based on the action at Okinawa).

What do you all think about this operation? Was it careless to attempt it? Would it have postponed the Cold War?

How do you think Operation Downfall will be reflected in Hearts of Iron IV?

 

[CrasherZZ]

In real life Japan would have surrendered because after Manchukuo and Korea were conquered by the Soviet Union, there was clearly no hope of even survival. The Soviet Union was actually the more "hated" enemy of Japan, as it was in Germany. Japan preferred surrender to the US rather than the SU, so once the SU was involved it was time to give in to the US before the SU could stake any claims to the mainland.

On the American side, there were some who thought that Downfall was unnecessary, even without the A-Bomb. They reasoned that Japan could be bombed and starved into submission - they were helpless to stop it. If Olympic happened, it would have undoubtedly succeeded. Unfortunately, there would have been massive civilian casualties, possibly even worse than what the a-bombs caused. Japan probably would've surrendered before then, and the US would've been anxious to end the war too because they wanted SU to have less opportunity to claim any more Japanese territory.

 

[Kozer]

I think you are under estimating the hate Japan built for the US. Their whole goal of the war was to make the US have such high causalities that they would be able to sue for peace on their terms.
Not only that, but the nukes did less damage to their country then the fire bombing that the US had been doing for months. But they were willing to fight to the end. Just to get that peace deal.

 

[CrasherZZ]

But they were willing to fight to the end. Just to get that peace deal.

Actually, we agree that they were willing to get a peace deal. Don't underestimate the "hate" between the Russians and the Japanese. There's a mucher longer history of conflict with Russia than with the US. Keep in mind that many officers and officials had gone to college or spent some time in the US, not in the SU.

The SU actually planned to invade Hokkaido before Olympic would have started. That would have forced Olympic to happen for sure. The end result would have been a divided Japan - a communist puppet in the north and a US occupied south. That's precisely what both Japan and the US wanted to avoid.

The cold war would not have been delayed because it was already on.

 

[PaxHadrian]

I think peace between the Allies and the Soviets was heavily influenced by the Allies use of A-bombs on Japan. While the Japanese did not know how many more A-bombs we could drop, neither did the Soviets. They certainly knew that we could reach significant Soviet cities and industrial zones if we launched B-29 raids out of India as well as those portions of Europe under Allied control (as well as the Soviet Far East). The cold war was, indeed, underway before the end of WW2. There is some interesting reading out there about the amount of Lend Lease from the Allies that the Soviets held in reserve for the conflict that they thought would break out between the remaining two major power groupings once the AXIS was defeated. I've heard that Churchill actually pushed for the liberation of Poland after it had been 'recovered' by the Soviets.

Has anyone seen anything about the odds of Operation Unthinkable occurring - newly declassified info since 2000?

 

[Darksaber501st]

What do you all think about this operation? Was it careless to attempt it? Would it have postponed the Cold War?

It would have been brutal, but without an atomic bomb it would have been necessary, if only to keep the SU from doing it themselves. It might have actually accelerated the Cold War by forcing the US military into yet another situation where it came into direct contact with nearby Soviet forces participating in their own offensives.

How do you think Operation Downfall will be reflected in Hearts of Iron IV?

I doubt most people will manage to keep history that in line until the war's end, but maybe the AI will surprise us. I expect to see a US island-hopping campaign, and I hope the AI is intelligent enough to mount an effective assault against the Japanese home islands if the island-hopping works. It's really going to need to be able to plan a coordinated, multi-prong attack, and also have enough first-wave and reserve troops to make it successful. None of this 1-2 divisions at a time HOI3-esque silliness, but a real, massive invasion force. If the devs can, I'd like to see atomic weaponry used in a tactical setting the way they planned for Downfall (if the AI has enough bombs), rather than just the strategic setting it was most used IRL and in HOI3.

 

[CrasherZZ]

On the Japanese side, they were planning a massive kamikaze campaign far larger than even Okinawa. They had thousands of aircraft and hundreds of boats a short distance from where the invasion fleet would have been. They planned to target the transports and assault ships instead of the capital ships.

Tactical nuclear weapons plus massive kamikaze attacks on troop transports would have made it far more hellish than even the Battle for Berlin.

Don't know if HOI4 is going to model it that way.

 

[Vukodav]

As Crasher said, it would be rather pointless. Japan would surrender after the fall of Korea and Manchuria anyway, just like Germany wanted to surrender as much as it could to the western Allies instead of Soviets. The operation on that scale could very well take the war into 1946. Just look how much it took to prepare Overlord, and that was for Germany that was in a worse position to defend than Japan. By that time, the only remaining industry Japan had, that was in Manchuria, would have been overrun by Soviets (who agreed to enter the war 3 months after Potsdam conference) in August anyhow.

As soon as that happened, Japan would seek an agreement with the USA in order to stop any Soviet landing on the mainland Japan.

If the Downfall did happen, yes, it would be hellish. But no one wanted it to be implemented and there was no real need for it. It is like operation Unthinkable - a plan made just in case it was needed but no one wanted to actually use it.

Well, at least that is what I think on the subject