1939: Japan gets The Bomb (RAR!)

[Zor]

In this rather dark scenario, the Japanese government acquires a strange artifact found off off the coast of Korea in 1934. It is part of a greater device that they believe to be a form of mining robot of some sort and is dated to being over a million years. The artifact that is intact and functional is a 2 meter cylindrical shaped affair with both an input and output that they manage to power up after some time. What it does is that if you feed ground up material into it it would process it into small cubed pellets about 0.3mm to a side, sorted by both elements and isotopes. Among these these is Uranium 235. As such, they are soon able to produce enough more than enough material so that the Navy can begin work on an actual device. On April-5th, 1939 they demonstrate to the US, British, German, French and Soviet Ambassadors (as well as some select members of the press) on the island of Iturup a 15 kiloton "Second Sunrise". This is the second such detonation, an earlier test bomb was detonated two months beforehand. In both cases, the devices were large and complex machines intended to test if the devices could work rather than something intended to be dropped out of an airplane, though they are working on that.

The Processor can provide enough Uranium every year for five such weapons every year. They are continuing research into other methods of processing uranium in case the Processor stops working. They are also looking into nuclear power.

Zor

[Purple]

Knowing the Japanese they'd end up using most of these on Chinese cities for maximum overkill and still lose to America. After all, that's what they did historically with most of the resources that were sent to the IJA.

[Ziggy Stardust]

Where are they getting the heavy water? IIRC, in real life, the major obstacle to the Japanese nuclear program was the lack of a source of heavy water. They had the theoretical knowledge (Nishina was one of the pre-eminent nuclear physicists in the world) and they had the capability to obtain uranium (admittedly, not in large amounts, but some of this was a consequence of wartime resource shortages and Allied bombing raids, which wouldn't be happening in this hypothetical scenario), but had no way of producing heavy water.

[Borgholio]

Well first thing is a massive arms race. The major powers would immediately start work on their own bombs as well as countermeasures against the Japanese bombs should war begin sooner than expected. We needed the massive B-29 to carry the first Atomic Bombs...so the Japanese would need to use something similar. Against an enemy with a working air force and intact air defenses, delivering the bomb would be much more difficult than it was against Hiroshima or Nagasaki, since the Japanese heavy bombers were basically big, fat, slow targets.

If it came to war, the Japanese would be stuck between a rock and a hard place. If they attacked sooner rather than later, they'd have a limited number of bombs and that might not help vs a large scale attack. If they waited until they had a large number, other nations might have time to build their own bombs which would negate their advantage.

I can also see war starting almost immediately by some who want to knock out their ability to build new bombs. While I'm sure the processor would be incredibly top secret, eventually it would become a target.

[Elheru Aran]

Japanese war technology was, apart from some minor points here and there, fairly unimpressive compared to what the Western world could achieve mainly due to limited resources and unimaginative designers. They had a superb light fighter (Zero) and some excellent pilots, but frankly the only thing they really had going for them was an insane compulsion to defeat the enemy no matter what the cost and the resultant willingness to completely brutalize the people they defeated.

They had a pretty decent navy but without an carrier aircraft capable of carrying the Bomb-- which could be possible if they're able to miniaturize it in time to something that can be carried by a B-25 equivalent, though that would be an one-way trip for the pilot as it can't be landed back on the carrier again.

Anybody want to give us an IRL timetable for nuke sizes? I know they had the Davy Crockett by the 60s...

[Simon_Jester]

The Japanese can probably downscale their bombs to the one or two ton or so level required to deliver them out of the available airplanes after... I don't know, five years sounds about right. Lack of precision tooling and supplementary technologies may hurt them, as might lack of computers to do calculations.

However, Japan is going to chronically lag in airplane technology for the foreseeable future, so nuclear bombing missions will remain risky.

[Elheru Aran]

Really the only reason the Japanese had a lot of initial success in the East was because they first knocked over a good chunk of China, which was in no shape to fight back, and then they started hitting various colonies that had essentially either been emasculated by powers paying more attention to the conflict in Europe or taking them by surprise. Pearl Harbor was the quintessential example of a surprise attack.

After that, about the only thing they had to their advantage was their tenacious hold on the various islands necessary for strategic purposes, forcing the US to spend a lot of time rooting them out, and a pretty decent navy with plenty of carriers. After the Coral Sea (inconclusive for both sides, IIRC) and Midway (clear American victory) though, they got a kick in the teeth and as far as I know they never really had anything they could legitimately call a victory against the US or the Brits. When the Soviets got into the game, they folded (although one could argue that it was more a matter of them getting nuked right before the Russians declared war).

As for the hypothetical:

More or less, it comes down on how actively hostile the other world powers are towards Japan having the bomb. If they're like "hmm that's interesting, let's do that ourselves" it's quite possible a Cold War type situation could develop.

On the other hand, if the Japanese start using nukes in warfare-- say to level Chinese cities-- then it's possible someone might move against them, perhaps trying to eliminate their bomb-production facilities. An open attack might be out of order due to fears of getting blown out of the water, but a stealth attack along the lines of the Doolittle Raid might do the job.

Since the Japanese already have the bomb, it behooves them to focus upon miniaturizing it for tactical use. It would be an extremely useful naval deterrent, for example-- a couple of aircraft could completely obliterate a carrier group. Methods of delivery are also worth developing, namely rockets. The rest of the world has to play catch-up, although the US does have the benefit in that (at this point, IIRC) they have Einstein and all the other scientists they had for the Manhattan Project.

If the Japanese have signed the Axis pact with Germany and Italy at this point, it's quite possible they might be induced to share... well, a Google indicates it was signed in September 1940. They may feel they no longer need to join the pact. That could make things different from a diplomatic and military perspective. It's vaguely conceivable, for example, that America might go to war against Japan alone rather than joining WWII in Europe as well.

[K. A. Pital]

Japan nukes Pearl Harbor

[Borgholio]

Japan nukes Pearl Harbor

That was actually my first thought...but even assuming they can drop a nuke with the hardware at their disposal, the end result could very well be the same...we declare war but we start using our own atom bombs much sooner and much more frequently.

[K. A. Pital]

Japan nukes Pearl Harbor

That was actually my first thought...but even assuming they can drop a nuke with the hardware at their disposal, the end result could very well be the same...we declare war but we start using our own atom bombs much sooner and much more frequently.

What if they actually manage to nuke the continental US?

[Isolder74]

What if they actually manage to nuke the continental US?

The only way that the Japanese could manage that would be from aircraft either from a full carrier or from one of their Submarine carriers. Given the size of the available aircraft that would be defiantly a Kamikaze mission from start to finish. They didn't have any craft that wasn't a seaplane, and that would still need a refueling sub, that would be able to reach a west coast city and drop a weapon on it. They'd be better off trying to drop nukes using their balloon bomb rigs then with a manned aircraft and that wouldn't give reliable results.

[Borgholio]

Japan nukes Pearl Harbor

That was actually my first thought...but even assuming they can drop a nuke with the hardware at their disposal, the end result could very well be the same...we declare war but we start using our own atom bombs much sooner and much more frequently.

What if they actually manage to nuke the continental US?

If they somehow had the hardware to do that, well...things would get really nasty really fast. I know the paranoia and anti-Japanese sentiment would be an order of magnitude worse than it was IRL, so I would think the Japanese living in the US would not fare too well.

As far as military action, we adopted the "Europe First" policy because we felt Hitler was the bigger threat. This might reverse the situation...where we focus everything on the Pacific and give just the bare minimum we can get away with to Europe. I can't imagine we'd sit out of the fight knowing we were nuked without provocation. Probably the safest course of action (without knowing exactly how many bombs they have), is to fight delaying actions with their fleet to knock out as many ships as possible without exposing our own forces to nuclear attack. We'd still have industry on our side...so using that to build submarines and long-range bombers would be a good idea. Our carriers would have to stay always on the move but they could harass the enemy fleet units as well, or be used as a picket line to try and intercept any potential long-range Japanese atomic bombers. Our island-hopping campaign would probably not happen since as soon as we overrun an island, it can be nuked. We'd want to wait until we had our own bombs so we can nuke THEM instead, keeping a few key islands to be used as airfields but glassing the smaller ones.

The Manhattan project would probably begin much sooner as we try to develop our own atom bombs to use against the Japanese mainland. Once that happened...millions would die.

Long story short, the Japanese would advanced farther but eventually they'd be pushed back with far more devastating results. Even if they can fly all 5 bombs they make every year, over the standard timeline of 4 years (1941 to 1945), that's "only" 20 cities / fleets / military bases destroyed. That wouldn't be enough to stop us dead in our tracks. And if the Soviets got into this, there's no way 5 atom bombs a year can stop the millions of troops that could flood into Japanese-held territory.

[Elheru Aran]

Our island-hopping campaign would probably not happen since as soon as we overrun an island, it can be nuked. We'd want to wait until we had our own bombs so we can nuke THEM instead, keeping a few key islands to be used as airfields but glassing the smaller ones.

Bear in mind that the Japanese had a taste for extensive tunneled fortifications. They wouldn't be awesome protection against getting a nuke dropped on their heads... but they were pretty good as it was. We're talking withstanding hours of bombardment from ship artillery and rockets. A 1940s nuke would be a bit more powerful than that, but not by a whole lot; it would just happen a lot more quickly.

[Borgholio]

Bear in mind that the Japanese had a taste for extensive tunneled fortifications. They wouldn't be awesome protection against getting a nuke dropped on their heads... but they were pretty good as it was. We're talking withstanding hours of bombardment from ship artillery and rockets. A 1940s nuke would be a bit more powerful than that, but not by a whole lot; it would just happen a lot more quickly.

True but I'm mainly thinking about their ability to use the island bases as airstrips for their atomic bombers. Sure we may not get the pilots and troops in the tunnels, but we'll wipe out the runway and infrastructure they'd need to launch atomic attacks.

[Simon_Jester]

Since the Japanese already have the bomb, it behooves them to focus upon miniaturizing it for tactical use. It would be an extremely useful naval deterrent, for example-- a couple of aircraft could completely obliterate a carrier group.

Well, a couple of dozen. A very small number of aircraft would be likely to get fried by the group's air defenses, and if the ships of a carrier group observe a reasonable level of dispersion then you more or less need direct hits with these (relatively) low-yield nuclear weapons to sink them. On the other hand, since air defense consists entirely of AA guns, you lose a lot of the escorts' effectiveness this way.

Even making an air-droppable version of the bomb will probably take Japan some years of effort and several test iterations, plus a matching effort to improve the payload of their bomber aircraft.

Methods of delivery are also worth developing, namely rockets. The rest of the world has to play catch-up, although the US does have the benefit in that (at this point, IIRC) they have Einstein and all the other scientists they had for the Manhattan Project.

The technology to build rockets that are accurate enough to matter here is... still a ways away. The Japanese supply of fissiles is quite limited, and if they try to build an ICBM with 1940 technology it won't get close enough to the target to be worth the effort.

They'd do better to load the bomb into a stupidly large flying boat and fly the distance...

[Elheru Aran]

Re: rockets. Absolutely, although the US had Goddard and the Germans had von Braun. Bit academic though.

I think the most important question here is, is WWII actually going to happen? If so, how will it look?

Before this point, Japan has already colonized Korea, invaded China and have some decent holdings in these countries. On April 5th, 1939 nothing of particular note happened. The Spanish Civil War had just concluded. Italy will invade Albania on the 7th. Germany and Italy haven't signed the Pact of Steel yet. The invasion of Poland may happen in August and set off the war.

Is the Bomb going to change the dynamics of global relationships enough that the War won't happen? Or will it happen anyway, just looking very differently? Are the various nations going to ally the same way they did previously? And so forth...

[K. A. Pital]

Yeah, pretty much the question may be asked on whether the US would want to risk open war now or, alternatively (as its own atomic project is nonexisting) start making the bomb while Japan enjoys its newfound deterrent powers and actually completes the conquest of Asia and gets to keep the holdings, more or less.

There may not be a war at all, or it may be a very different war. Knowing that one of Hitler's allies in the Axis has a working atomic bomb, would Britain and France really go to war over an attack on Poland? Would the USSR ever sign a pact with someone whose Axis (Anticomintern!) ally has an atomic bomb and whose Strike Group North will soon attack Soviet forces.

[Borgholio]

Yeah, pretty much the question may be asked on whether the US would want to risk open war now or, alternatively (as its own atomic project is nonexisting) start making the bomb while Japan enjoys its newfound deterrent powers and actually completes the conquest of Asia and gets to keep the holdings, more or less.

There may not be a war at all, or it may be a very different war. Knowing that one of Hitler's allies in the Axis has a working atomic bomb, would Britain and France really go to war over an attack on Poland? Would the USSR ever sign a pact with someone whose Axis (Anticomintern!) ally has an atomic bomb and whose Strike Group North will soon attack Soviet forces.

Well as you questioned earlier, what if Japan nuked Pearl Harbor or the US Mainland to try and scare us out of the war? I'd wager there would very much be war, not a nuke going off over Honolulu followed by 4 years of playing catchup before we fight back...

[K. A. Pital]

That is if Japan did attack, yeah. But given the months before any real action, and given that the Japanese naval buildup was incomplete at the time, not to mention that its prevailing opinion was an attack North (on the USSR)... the whole US-Japan war might be doubtful.

On the other hand, a Nazi-Japanese joint attack against the USSR is quite possible. With a bomb Japan won't pussy out like they did IRL after being beaten in September 1939 at Khalkin-Gol.

[Elheru Aran]

In this situation Japan is suddenly holding a massive upper hand. However, the same economic pressures that forced it into fighting the Allies are still present. They are especially going to need petroleum (why they attacked the Dutch East Indies; the US cut off 80% of their oil imports in 1941) and metal supplies (in 1940 the US embargoed quite a bit of scrap-metal exports, which Japan depended upon for recycling into usable metal).

So they are going to have to get their resources from somewhere, and now they have the big stick to get it and do so with relative impunity. The US IRL started its embargoes when the Japanese initiated hostilities in East Asia and made connections with Germany and Italy. In this situation, it's possible they may not bother. Or they might start even earlier. There's no way to really know as the paradigm has just shifted considerably.

[Borgholio]

How long would the Japanese wait before attacking the USSR? The Soviets were industrializing rapidly, so Japan might not have time to build dozens of bombs. They might only have a few on hand which would not be enough to stop the entire Red Army.