AHC: Longest Time Needed to Change Tide Against Japan in WW2

The challenge, if you choose to accept it, is to posit a plausible series of events that keeps the tide from turning against Japan for the longest period time. Plausible changes of events in the European are allowed to add knock-on benefits.

The rules are:

-No PODs before the attack on Pearl Harbor other than...
-The Japanese do not have their codes broken by the British or Americans; and this continues for the remainder of the war
-They do attack Hong Kong and thereby bring the British into the war

Could the Japanese avoid a Coral Sea misadventure? Without the codes broken, what happens in Midway? Can New Guinea be taken in its entirety?

What weapons and tactics could the Japanese invest in to their benefit? What campaigns can they avoid that proved to be to their detriment?

I just watched Unbroken and now I am on a Japan kick :cool:
 
The best way to do it would be to wipe out the US carrier forces in the first six months - say, Big-E/Lex/Sara at Pearl, followed by Hornet, Yorktown, Wasp and maybe Ranger at alt-Coral Sea/Midway. Both battles turned on sufficiently fine margins that it wouldn't take much to turn them, and without breaking JN-25, Midway would be utterly transformed. This would give them at least twelve months carte blanche before the first of the war-built carriers started arriving.

I see the key implications of this as follows:
1) The Japanese will be able to continue to extend their hold over the south-west Pacific, and give them more time to fortify them, forcing the counter-offensive to reclaim more of these outer islands, and probably at even greater cost than OTL.
2) Far stronger forces will be available to respond to the counter-offensive, in terms of both carriers (no OTL Midway, more time to carry on building) and aircrew (no Santa Cruz, more time to carry on training).
3) The counter-offensive will begin against a backdrop of prolonged Japanese ascendency, rather than with them still reeling from the physical and psychological shock of Midway. This will probably cause it to be delayed until a far more favourable balance of forces is obtained than OTL's invasion of Guadalcanal, and to be pushed less forcefully. This will exacerbate point 2).

The end result is that I can't see the counter-offensive beginning until the first half of 1944, when the Pacific Fleet has been built up to sufficient strength to be confident of defeating Kido Butai in any likely action. This puts back the timeline approximately eighteen months from OTL's Guadalcanal, and three months from Tarawa. I believe the former is the more realistic delay, given the vital role the battles in the Solomons played in degrading the strength and capability of the Japanese forces to resist the Central Pacific offensive. Adding in the additional advance required and the far stronger Japanese starting point (say, another six months) I believe that TTL's advance would reach the same culminating point as OTL's (i.e. preparing for the invasion of the Home Islands) by approximately June 1947. If Downfall proves necessary, that pushes the end of the war back to at least March-April 1948 (assuming TTL Olympic is 1 Nov 47 and Coronet 1 March 48).

There are three major factors that aren't or may not be affected by this POD.

The first is that it won't delay the Manhattan Project, which will still produce a deployable atomic weapon by July 1945. This means that it is possible that the first Superfort raids on Japan (approximately November 1946, assuming the rule above of OLT+2 years) will be nuclear, and will bring an end to the war as OTL. On the other hand, Truman (assuming this this chain of catastrophes doesn't kill Roosevelt early, cost him the '44 election, or change his thinking regarding his running-mate) may be advised or want to hold off launching nuclear raids until Japanese air defences have been degraded.

The second is August Storm. Despite the US still being half-way across the Pacific at this point, I believe it's still likely that the Russians will come stomping across the Manchurian border in August 1945, perhaps moreso, as they'll have a plenty of time to grab what they want before the US shows up. Whether this will by itself trigger a Japanese collapse probably largely depends on your view of what caused the OTL surrender, but in this case it will probably occur at either the same time or shortly after the invasion of the Marianas. What Stalin does next is anyone' guess - he may try and launch an invasion of the home islands or he may content himself with the Kuriles and turn his attention to the rest of the Japanese army in China.

The third wildcard is the submarine campaign. While I do not believe it could end the war on its own, it would effectively isolate the home islands, and accelerate the fall of bypassed outlying positions by reducing the defenders to a state of starvation. Whether it could do so to a sufficient degree to accelerate the progress of the main offensive is highly questionable.
 

Ian_W

Banned
The third wildcard is the submarine campaign. While I do not believe it could end the war on its own, it would effectively isolate the home islands, and accelerate the fall of bypassed outlying positions by reducing the defenders to a state of starvation. Whether it could do so to a sufficient degree to accelerate the progress of the main offensive is highly questionable.

Considering neither of the two sovereign powers allied against the West in the Pacific War, the IJA and IJN, considered building oil tankers, oil storage facilities, oil refineries or oil drilling capability important, yes, the submarine campaign alone will do the job by running Japan out of oil tankers and therefore oil.
 
Cutting to the chase: mid to late 1943. That was when US naval construction surpassed the Japanese in absolute terms, even assuming a flawless IJN performance at Coral Sea, Midway, and the like.
 
It's implausible that the Japanese could keep their codes a secret; their cryptography was way too unsophisticated to be secure.
 
I'm more inclined to say, all things being equal, late 1943 up to early part of 1944, this assuming a flawless performance of the Kido Butai in 1942 and possibly a third CV battle with a still not numerically superior USN carrier force in late 1943 (say 10 vs 10 or so), which might give the japanese a pyrrhic victory if the americans are on the wrong foot again (in OTL the americans apparently split their CV force in several small groups for the Tawara operation). So it could be spring 1944 when things finally turn for good against Japan, but starting from the shores of Australia and the South Pacific (assuming Port Moresby was taken in 1942 as well as at least the New Hebrides and maybe New Caledonia and Fiji, plus Midway- but it would likely have been taken back in late 1943)

As for the subs, if the front is significantly further away in early 1944 compared to OTL, then of course it will be that much more difficult for the US subs to operate against japanese shipping, so the critical losses from OTL might be delayed several months at least, maybe up to late 1944 or early 1945.

Of course, it would also be interesting to see what a victorious Japan in 1942 in the Pacific might mean for the Burma-India-China fronts as the most Japan could achieve there.
 
I think Captain Seafort's post breaks it down good enough, though it breaks a rule in the OP...Pearl Harbor goes down as per OTL. The US would have to lose their carriers in an ATL Coral Sea/Midway.

Of course, it would also be interesting to see what a victorious Japan in 1942 in the Pacific might mean for the Burma-India-China fronts as the most Japan could achieve there.

That is a good question. And, can Japan take the entirety of New Guinea? Does Japan get enough oil from Dutch East Indies? Does Russia even offer to fight a non-almost totally defeated Japan ITTL? Do the British send more naval assets to the Pacific?

I think a possible knock on effect is a pacification of China to some degree by 1944.

Further, Japan's weapons development looks like crap. If the war goes into 46, which ITTL it probably does, Japan even with better pilot training and more planes won't be able to stop B29s and their atomic payloads.
 
That's the OP. A Japanese Einstein of cryptography was born and made unbreakable codes ITTL :cool:

I know. It's mathematically impossible to do with the book codes they used OTL, and they didn't have any tradition of using rotor machines like the Enigma. Even if they did, the Allies walked all over that, so to make a variant that was orders of magnitude stronger doesn't seem possible. It's no more logical than handwaving their shortages in shipping capacity or aviation fuel.
 

TFSmith121

Banned
Saratoga was in San Diego in December, 1941

The best way to do it would be to wipe out the US carrier forces in the first six months - say, Big-E/Lex/Sara at Pearl, followed by Hornet, Yorktown, Wasp and maybe Ranger at alt-Coral Sea/Midway. Both battles turned on sufficiently fine margins that it wouldn't take much to turn them, and without breaking JN-25, Midway would be utterly transformed. .

Saratoga was in San Diego in December, 1941, and Enterprise was halfway to Wake; the only US carrier even remotely close to the IJN's withdrawal route was Lexington, and its December in the North Pacific, so, yeah, good luck with this one...:rolleyes:

Without the codebreaking, the US doesn't send anyone out to Midway, so the IJN sails around, bombards an island they can't sustain a garrison on, may (or more likely, may not) take it after a bloody debacle at the water's edge that makes 1st Wake look like a picnic, and then leaves... and a month later, the US takes the atoll back from its starving Japanese defenders.

But other than those minor issues, great plan.;)

Best,
 
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