Japan decides against Midway and invades Australia instead

lwd wrote:

You're right. As a diversion it's a no go. It would have to be a full fledged campaign, and the Aleutians operation would need to go away also.

ickysdad wrote:

You're absolutely right, but initially Japan will have the advantage. They have to hit hard, fast, then dig in deep. The US will initially rush everything possible to Australia to attempt to prevent further deterioration of the situation, but there's not much available. They'll then have to decide if they want to reorient from a Europe first strategy and if so to what degree. Then they'll have to reallocate resources, redeploy resources and finally ship them to the area of operations. It all takes time. Once America's industrial might makes itself fully felt it's all over but the crying. Until then they can keep the situation in doubt.

 

I never suggested the Japanese carrier fleet was “invincible”. I stated that what was most dangerous to them were (1) the US carriers and (2) tangling with major air base defence networks such as to be found on Oahu. With the exception of Australia itself, there were no major land bases in the South Pacific during 1942 that could stand against massed carrier strikes. That means the US carriers would be employed primarily defending the supply lines to Australia, seeking there opportunities to exercise Nimitz’s doctrine of calculated risk at some point of contact or another. And that means that the US carriers would not be elsewhere - off on some crazy adventure at Perth for example.

So long as the USN had its own powerful carrier forces in the theatre, the Japanese could most certainly be defeated. Only if the US were crazy enough to send their carriers elsewhere would Yamamoto have the run of the South Pacific.

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Assuming that Port Moresby and Guadalcanal are in Japanese hands and that the Japanese carrier fleet remains intact at Truk, where exactly would this offensive be aimed at?

Each US sub could only be in one place at a time and there were plenty of places for prowling better than a supply route to Darwin.

 

Okay, Glenn239. I am glad to learn that the Japanese carriers are not "invincible." I have to admit that what you posted earlier seemed to point that way and I misunderstood your intent. I am glad that's cleared up. Personally, I think most of the points that can be explored in this scenario have been discussed already.
Here's how I see what have been posted by everybody so far:
The Japanese can land and invade Australia if they wanted to, especially if the Midway battle didn't happen.
They would enjoy the initiative and give the US and Australian leaders restless nights, maybe for the first month or so. But once US and Australian forces consolidate their defence and determine the extent of the Japanese committment, it's likely the Japanese offensive would run out of steam. And with US production and mobilization ramping up, the Japanese would be on the disadvantage.
As to opening up another offensive, I think the US would could strike through the Central Pacific once the Japanese have exhausted themselves in Australia and the surrounding waters. Go through Wake, the Marianas, then the Philippines with a supplemental attack up Southeast Asia with forces from Australia. This loosely based on what historically happened and I think it would go along these lines once the Japanese invasion of Australia is contained. With the losses in shipping and aircraft that the Japanese would undoubtedly suffer in the campaign, plus the coming of line of new US fleet units, the Japanese won't be able to contain this onslaught. But this is better dicussed, I think on another thread.
Because of this thread, I think it's time for me to review Morrison's books on Midway and Guadalcanal.

 

Interesting topic in that a possible invasion of Australia scenario rarely gets much of a mention, & although there were no detailed plans for an immediate invasion it was a close run thing with plenty of high ranking Japanese voting for a move against Australia.

And 'if' things had taken a slightly different turn, it could have gotten more then a bit scary down under in '42.

After the initial phase of the Japanese blitzkrieg came to a successful conclusion, which the Japanese had achieved all their initial war objectives ahead of schedule and with astonishingly slight losses, most Australians thought it wasn't a case of 'if' but 'when' the Japanese would invade.


Darwin seemed the obvious place to make a easy landing, but the Japanese would be isolated in the North or West, their best chance of breaking Australia's ability to wage war would be an invasion of the East Coast in the Wollongong/Port Kembla/Sydney area, but the taking of Darwin [or Port Moresby] would bring the East coast almost as far down as Brisbane in range of IJN bombers.

With Australia's armed forces stretched to the limit & the best divisions & Commanders fighting in Europe, North Africa & the Middle East against the Germans, Italians & French & ditto for the RAAF personal flying along side the RAF in Britain & Europe, there wasn't much left to stop a determined assault on Darwin.

Australian defense chiefs & senior American officers was wondering whether Australia could be held. Brigadier General Leonard T. Gerow, assistant chief of staff of the war department in Washington began his own assessment on 17 January with the unsettling words:

“…it is not practicable to state how long Australia will remain in friendly hands.”

Gerow didn’t think the Japanese would try to conquer all of Australia, but acknowledged that the enemy could occupy portions of the country, bomb any cities with carrier-based aircraft and, if they seized New Guinea and New Caledonia; bomb northern Australia with long-range bombers.


1942 - Australia's Greatest Peril

The defense chiefs were prepared to give up the North & defend the Southern Boomerang, or the ''Brisbane line'' the area between Brisbane & Adelaide.


But I guess it was lucky for everyone in this neck of the woods [& the Americans] that in planning phase two of their operations...what to do next..., the Japanese, picked up a fatal disease, [Later this this unrealistic attitude was coined as "victory disease"] & rather than consolidate their conquests and build their defense perimeter as originally planned, ''victory disease'' was impelling the Japanese to disperse their overwhelming superiority in support of too many operations across too great a distance which led to their defeat at Coral Sea and Midway, handing the initiative to the Allies.


And although the USN lacked the Naval strength at that time to match Japans, they enjoyed one importent advantage in the clandestine electronic war, ..the Cryptanalysts...were surely the key to tactical supremacy in the enormous reaches of the Pacific battleground.

 

ANZAC
Very good informative post. Also, I very much liked the attached article.

 

Check.

Check.

Within 3-4 months or so. The Allies would have as much difficulty fighting in the Outback as would the Japanese and the campaign might take over a year.

Without the Solomons to attrite the Imperial Navy, any offensive in the Central Pacific before 1944 would be quite dangerous. After 1943, then the USN could start to roll because the islands are too small for major land based airpower and the USN will have carrier and aerial superiority.

The Solomons Campaign resulted in something around 350,000 Japanese troops being bypassed, to say nothing of the 100,000+ killed outright. That’s the trick to this 'what if'. The premise avoids two huge Japanese pitfalls right from the start; Midway and the IJA’s indifference to the Pacific Theatre in 1942. Further, it offers a way to avoid the Solomons campaign, which resulted in a scale of disaster for the Japanese that I think is being seriously underestimated. A Darwin campaign would eventually result in a Japanese retreat, but there would not be any bypassed troops in Australia; they’d either be dead or long sailed away.

 

Assuming a major invasion, I think a strong case can be made that the Eastern option would be likely to fail due to the difficult communications there. If conquest (not diversion) is the name of the game the best time to have done it was December 1941, and the Philippines invasion would have had to be cancelled to provide the necessary forces.

The other invasion route was from the west, Perth. The advantage to Perth (in addition to Darwin and assuming a major invasion) was that the communications were secure and the supply lines again benefit from supply ships running to Perth loaded with war material, and running back to Japan with raw materials from the NEI, with an opportunity to refuel going in either direction.

The problem with the original strategy was that it could not work. Yamamoto sensed, perhaps earlier than the others, that no amount of consolidation was going to matter a whit when the counterattack began in 1944. To revert to the defensive in 1942 was simply to admit the war was lost, and await the end on the enemy's terms.
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Thanks USMCPrice, appreciate the kind words, & glad you liked the link.

At the time there was no plans to even invade Darwin let alone make a full scale invasion as some IJN factions wanted, & as events unfolded they were never raised again [Thankfully]

When the joint conference of Navy and Army Sections of Imperial General Headquarters was convened in March 1942, the Japanese generals rejected the claim by Navy General Staff that only three army divisions would be required to capture and hold key areas of the Australian mainland. The generals insisted that a successful invasion of Australia would require at least ten army divisions which they could not spare at that time. Moreover, they claimed that they could not provide logistic support for ten divisions in Australia at that point of time.

Besides, Yamamoto was not interested in an invasion of Australia at this time because he believed that destruction of the US Pacific Fleet should be Japan's top strategic priority.

But of course the Aussies & Americans didn't know this....in early March 1942, the commander of US forces in Australia, General George H. Brett, who was about to become, briefly, General MacArthur’s deputy, prepared an estimation of Australia’s grim position in conjunction with Australia’s three defence chiefs, Burnett, Royle and Sturdee. Brett and Australia’s senior officers said their best forecast was that Japanese attacks may occur on Darwin in early April, Port Moresby in the middle of March, New Caledonia in the middle of April and on the east coast of Australia in May.

''We visualise that, should New Caledonia be occupied, the next step of the Japanese might well be to attack the east coast of Australia.''

All I can say is thank heavens for the IJA [& Yamamoto] for winning the debate on what to do next.




Not much doubt that 'anything' the Japanese tried after Pearl Harbour would just end up with the mushroom clouds rising over their cities.

But I wasn't suggesting that the Japanese go completely defensive until '44, just complete Operation FS, & secure Port Moresby, New Caledonia, Fiji, the Samoan islands first, 'then' Yamamoto try his Midway ploy.

But I guess with the US Navy cryptographers breaking Japanese Navy crypto systems, the IJN was always going to be hamstrung.

By all accounts even with the publication of that fact in the Chicago Tribune shortly after Midway, the Japanese didn't seem to have noticed because they kept using the same system for some time.