The invasion of Oahu, December 1941.

[ChristopherPerrien]

Alright , I think what y'all are missing is the US had a fairly clear picture of Japnese intentions and the forces massed in various areas for action. The ONLY force that the US states was not aware of and its "location" was the 1st Airfleet .

Details of the formation, training, and assembling of each of these Japanese naval elements (except for the Pearl harbor Attack Force),as well as the supporting Japanese air elements involved in the Southern operations, were reported by the COMINT centers in Hawaii and Corregidor. Specifically, they observed Japanese air and naval forces gathering in the vicinity of Takao and Keeling on Formosa and Mako in the Pescadores, a group of islands between Formosa and China. They also noted Japanese assault forces gathering on Amami O Shima north of Okinawa and in the Palau Islands in the Mandates. Air support for the Philippine assaults was also seen assembling in the Palaus and on Formosa.

http://www.ibiblio.org/hyperwar/PTO/Mag ... #ComInt-19

Now with this "attack plan", y'all are proposing to use these other forces ( whose locations and general intentions were known) to attack Hawaii. It follows that these other pieces of the puzzle will point toward an attack on Hawaii when you move them that way. The one missing piece(1st airfleet) which allowed the 'raid" to be a suprise, doesn't preclude that moving all these other pieces will go "un-noticed" or that this "new picture" will not become readily apparent even if the one piece of the puzzle (1st airfleet) is still missing. In a past job, I have constructed such pictures, with limited/partial pieces, from them you can both see the whole picture and even, eventually, the shape of missing pieces.

Chris - can you post a link to the thread to which you are referring?

The first page of this thread

The size of the IJN fleet train is provided in post 2, with a breakdown by type. Note that what you are describing as "infinitesimal" was in actual fact a massive 1.8 million tons of shipping. Do recall that the entire Japanese economy could get by with 3 million tons.

okay a 1.8 million ton elephant + the weigh of the IJN.

You're using blanket figures of the Japanese merchant marine. That does not nearly compare to the same size and specialization of the US fleet train that supported the USN/ Saipan amphious attack force. It took years of hard work and thinking and experience for us to mount this size of landing/assault on Saipan. And the assets of AMERICA. The Japanese had none of this in 1941, neither did they ever mobilize or purposely build remotely this much shipping to mount an amphibious attack. Throughout the war they had problems merely making amphibious landings and their attacks/assaults on defended beaches number (2), Corredigor and Wake. Both of which were near-run/ slip-slod operations of an insignant size compared to this Pearl harbor assault (about 1:30to40 in troop size IIAC).

Even the Midway invasion force numbered only 4500 men. I think this is the upper limit to how big an amphibious ATTACK the Japanese COULD mount for the war. Look at the problems they had just landing troops/supplies/equipment on Guadacanal. This gives a fair indication of the actual ability and capabilities of the IJN/IJA to land and support troops and their Guadacanal ops were a war-year later.

Hardly. If you would devote some time to reading (other than sigint) about the China/Japan war ongoing before WW2 you would note that Japan succeeded at some 27 over-the-beach combat landings there.

I'm a bad historian, as I don't know about these 27 SaipanOTL/HawaiiATL Invasion sized amphi attacks. Please list them and exclude landings of less than a division(for simplicity) and the ones where the opposition was a few Chinese peasants/militia armed with hoes and rice-threshers.

Note there is a huge difference between an Amphious attack/assault and merely debarking/landing from a ship.

As I have typed before, the US couldn't find invasion fleets that it WASN'T even searching for.

They did find them. see above. and previous posts and topics.

I can claim 35,000 regional sea miles logged in a 48' sailing bark. Can you ?

No , a 775' AKA , probably a few more miles. Here is a picture of the ship I was on for 14 months. We were based at Saipan/Guam and steamed all over the Western Pacific. Plus I flew the US/Hawaii/Saipan route a few times.
http://www.hazegray.org/shipbuilding/qu ... /mps46.jpg 48' bark? pretty brave. I'm no sailor.

, because its all part of the grand conspiracy, right ?)

I see no conspiracy, I just see not being able to track the 1st airfleet for a couple weeks, and a lack of belief by some higher ups about the possibility of an air attack on Pearl Harbor. The US was dam sure aware of and capable of defending Oahu from a NAVAL attack; Otherwise, How do you explain all those coastal defence guns and beach defenses and army units? However I do have a real problem with letting your enemy, "fire the first shot". Especially when that first shot is aimed at people much like me when I was in the Army. Politicians should stand in front of that gun when they think up such great ideas/conspiracies.

but I would point out that, had Japan grabbed Hawaii in December'41 a dfferent reality would have prevailed for the next 2-3 years.

Ha-ha. Hell Yes. They would have faced an attrition battle and losses which would have made Guadacanal look like bargain by comparision. An Unsupported base, with a supply line 1000's of miles long, Sitting right at the end of the "front yard" of the US west coast. Who needs oil tankers when you have oil wells to directly fuel up from. And US subs would have had alot of fun.


Of course it would never go this far, as the Japanese could never take Oahu. This plan on the first page says the Japanese will not invade Oahu till a few days after the first attack. If you give the US Army even a few hours to man the coast defences and the beaches you'll probably never land anything . Or at best, the light armed Japanese soldier will never make headway off the beach. The IJA never had the firepower to blast through dug-in defenses. Perhaps you can starve them out in 6 months like what happened in PI , but I REALLY don't think the IJN can hang out that long. What happens to any Japanese ships off of, or heading toward HI after about March 42, I leave to the imagination, as that was when the US broke the Operational code.

Chris

When you make a war-game/what-if you need to play or look at it from both sides, i.e. neutrally, otherwise you will never see the problems with perfect plans or stratetgies.
And don't underestimate the capabilities or adaptability of the US on ,or even long before, Dec 7 1941.

Even before Dec 7 1941 US SIGINT, was excellent, so was our HUMINT, and our COMINT got excellent once it was sufficently staffed(Feb-Mar1942). The exception of the Pearl Harbor raid proves the rule of the effectiveness/decisiveness of US intelligence in the Pacific War. Change Plan Z into anything other than a mere raid by a small force and you run smack into the generalization that makes this true. And you will probably make it a "quick war" , which if I recall, correctly was the hope of the Japanese in the first place.

[glenn239]

ht , I think what y'all are missing is the US had a fairly clear picture of Japnese intentions and the forces massed in various areas for action. The ONLY force that the US states was not aware of and its "location" was the 1st Airfleet .

Chris, I think you'll find the reason that these units were being tracked is because they were sending and receiving radio transmissions. I point out again (not the first time), that the USN's own report on their ability to track IJN units in the period leading up to the war, which is to be found in the concluding section, does not conform with the suggestion that an attack 'must' be discovered. The reason that the USN was able to guess at their intentions in the case you mention because they were gathering and chatting away at, “Takao and Keeling on Formosa and Mako in the Pescadores”. These locations are remote from the Home Islands,

Chris - can you post a link to the thread to which you are referring?

The first page of this thread

Can’t be this thread, cause anyone reading it understands that most of the invasion forces start the scenario in port. There is a sizeable force of naval vessels at sea - historically the Japanese deployed 35 ships at Hawaii, plus (guessing here) about 20 submarines for 55 ships altogether. This AH has about 75 ships, plus the same sub force, for about 95 altogether.

You're using blanket figures of the Japanese merchant marine. That does not nearly compare to the same size and specialization of the US fleet train that supported the USN/ Saipan amphious attack force.

I’m pointing out the fleet train attached to the IJN merchant marine. It cannot be described in the way you wish it to be. The IJN had a bigger fleet train than most nations at the time had merchant marines!

Also, do rest assured that the IJN didn’t conduct invasions in 1941 upon the basis of what the USN would do in 1944. If this were the standard, then there wouldn't have been a war.

Corredigor and Wake. Both of which were near-run/ slip-slod operations of an insignant size compared to this Pearl harbor assault (about 1:30to40 in troop size IIAC).

What IJA units are you thinking participated in the 1st attack on Wake?

At Corregidor an IJA division (4th) attacked the fort over the beach, took out the 4th USMC Regiment and then captured the garrison of 11,000 men in 24 hours, didn’t they?

With respect to Oahu, I have mentioned already that the historic assault on Oahu was to be conducted by three IJA divisions. While it may be true that these operations were “slipshod” in comparison to USMC practice that didn't exist yet, it is not true that the IJA believed itself incapable of conducting them.

[robdab]

Chris,
Thank you for providing the http://www.ibiblio.org/hyperwar/PTO/Mag ... #ComInt-19 source. I had not seen it before and it is a most interesting summary of the information that I had previously gleaned from the books by Layton and Rochefort

Without getting into a lot of details, I would just like to point out however, that even WITH the benefit of all of the COMINT that you claim from this source historically, the Americans, British and Dutch STILL got their butts kicked by the Japanese in the early war period. Historically it IS apparent that none of the Allies could motivate their defense forces, even with this limited amount of advanced warning, sufficiently to hold off the Japanese. Most of the Phillipines were still quickly overrun with the exception of a few cut-off fortresses. As were Hong Kong, Malaya, Borneo, Java and all the rest.

Why is it that you believe that the defense of Hawaii would have been any different had those islands been Japan's objective of choice ? Your source CLEARLY indicates that the IJN messages intercepted by the US that WOULD have revealed Japan's historical intentions were NOT decoded until 1946-47. Had those targets included Hawaii INSTEAD of the Philipines it still would have been 1946-47 (or maybe later) before those same messages were decoded. Traffic analysis obviously could have been used to indicate where Japanese forces WERE based, WERE concentrated and WERE loading but since the actual message contents could NOT be read at the time, that DOESN'T indicate just WHERE they have been ordered to invade, does it ? Hawaii DID receive not one, not two but three WAR WARNINGS from Washington thru the month of November and STILL got the stuffing knocked out of it, so what makes you think that a fourth or fifth would have made much of a difference ?

Wrt early war Japanese amphibious landing experience/acheivements PLEASE look up the Dec.8'41 Khoto Baru combat landings at the Thailand/Malaya border area. Multi-divisional combat team landings where your so called "lightly armed" Japanese stormed ashore against fortified beaches which included mines, barbed wire, bunkers and machine guns manned by British and Commonwealth troops, backed up by airstrikes from airfields just behind the beacheads. The Japanese won those beaches and the remainder of the Malaya campaign quickly followed, to Britain's regret. Read about the NEI landings after that.

To site ONLY Wake #1 and the aborted Midway landing as examples of the amphibious warfare skill set held by the IJN/IJA is self-delusion of the worst kind AND is precisely the reason WHY the Japanese defeated the Allies so consistantly during the early Pacific War period. The Allies just couldn't bring themselves to believe that Japan was even capable of attempting such efforts. But, Japan WAS, and did so, consistantly. Corregidor WAS a Japanese divisional attack (granted, via landing barge from a shoreline only a short distance away, not from ocean going ships BUT...) against NOT only defended beaches but against a small island totally converted into a FORTRESS of great defensive strength. It must be mentioned that Corregidor WAS a VERY close fight indeed for those Japanese victors however. They were within an hour of withdrawing from Corregidor due to a lack of ammunition when the Americans surrendered. And so many of their landing barges were shot up by the defenders that subsequent Japanese landing waves were not possible. Close, but STILL good enought for a 1st place win !

Another of your comments was:
"The US was dam sure aware of and capable of defending Oahu from a NAVAL attack; Otherwise, How do you explain all those coastal defence guns and beach defenses and army units ?"
Yes, but if you read the long term, NUMEROUS and rather frantic messages sent back to Washington by Short, Kimmel and Richardson (Kimmel's predecessor) requesting more infantrymen, more trained coastal artillery gunners, better AA guns and aircraft of ALL types it becomes VERY obvious that the commaders 'on the ground' in Hawaii, felt themselves to be EXTREMELY vulnerable to attack. Especially wrt the LACK of sufficient numbers of long ranged SCOUT planes capable of sounding a warning with sufficient LEAD TIME for Hawaii to brace itself for an attack(s).

And, if you will notice, Glenn's plan has the Kido Butai seizing TOTAL air superiority over Hawaii while the Japanese Combined Fleet takes out the US Pacfic Fleet in the Decisive Battle so long held dear by Japan's naval planners. Just, two thousand miles EAST of where it was historiclly planned to occur. The IJA may not historically have had the power to blast beach defenses BUT the IJN will be close by to lend a helping hand, when needed, as they did historically all thru the NEI. I do believe that Glenn's forces include an IJA artillery formation of some 100+ heavy guns so he HAS taken steps to address this issue in his invasion plan. Don't forget Kido Butai air support initially, followed by ground based IJA bomber aid as Japanese airbases are opened on other captured Hawaiian Island airfields.

I HAVE looked closely at Oahu's CA defenses of the day and Glenn is correct in seeing that the island's southeast coast was only lightly defended. Once the long ranged, 360 degree 2x2x16" and 2x12" CA batteries are taken out by naval gunfire or bombing, there would be little that the US defenders could do (without air cover and the US Pacific Fleet gone east) to prevent the IJA from establishing their 100+ heavy guns on the Kaneohe Plains to provide heavy fire suport on demand. Any US defensive lines thus pinned in place could then be bypassed via the Japanese ability to land on any other (weather & surf allowing) beaches behind the Americans. Sure, the US defenders COULD garrison EVERY beach but then there would have been NO troops left to stand against the Japanese infantry on the frontlines, nor any reserve formations to pinch off Japanese nightime combat infiltrations. And to top it all off, the Americans had JUST finished dredging out deep water shipping channels thru the coral reefs of Kaneohe Bay so that the Japanese could more easily land their artillery, ammunition and troops there.

Personally, I agree with YOU in that allowing US 24th & 25th division defenders time to deploy to their beachfront (historically the first US infantry units were in their trucks & rolling from Schofield by 0930) defensive positions will GREATLY increase both the duration of the campaign AND the numbers of Japanese casualties (not that the IJA is all that concerned with casualty totals as long as the mission is acheived). I HAVE engaged Glenn in numerous and lengthy (off thread) discussions wrt this point, but, so far I have been unable to convince him of the wisdom of my point. Mostly because he believes that attempting to bring a Japanese invaison force LARGE enough to survive, ashore on Dec.7'41 will cause a LOSS of surprise and result in US defenders manning the beaches anyway. Along with a whole bunch of other 'bad stuff' happening, from a Japanese point of view.

I do intend to post my own "very fast & VERY risky" Oahu invasion varient but only AFTER Glenn has thrashed out his own alternative history invasion plan. My discussions here wrt a PH blockship were a part of that high risk plan. By delaying, I can take advantage of ALL of his hard work and basic research as well as be warned of any unexpected pitfalls. Sometimes I hate myself but I've learned to live with it !

Last but not least, your comment of:
"Especially when that first shot is aimed at people much like me when I was in the Army."
goes a long, long way to expalining why you can't accept even the thought of Hawaii being invaded by Japan, let alone being actually overun.

[ChristopherPerrien]

I suppose I have made a few errors of assumptions , I 'll correct them now. Please excuse any mild sarcasm , other readers may find it funny.

Can’t be this thread, cause anyone reading it understands that most of the invasion forces start the scenario in port. There is a sizeable force of naval vessels at sea - historically the Japanese deployed 35 ships at Hawaii, plus (guessing here) about 20 submarines for 55 ships altogether. This AH has about 75 ships, plus the same sub force, for about 95 altogether.

I have been using a figure of 200 ships somehow in this ATL this is in an error. I guessed the figure simply becuase it seemed about right(minimum plausible) and it is hard to cut and paste or remember everything presented in the first pages of this topic( Robdab is right, the size of the post/topic material precludes discussing problems in detail)

Needless to say 95 ships (which includes the warships too) is an amazing figure to land 3 divisions and support an amphibious landing(correction ASSAULT) 2000? miles away from the nearest sizable support base(Is TRUK built in 1941? I forget). Could you go fight my battle for OPERATION ROUND-UP in 1943? Because they(the Gnomes of Albion) tell me we( ALL THE ALLIES) didn't have the shipping to move 3 divisions 12 miles in AUG 1943, while underhandly either ignoring or contrarily using the Sicily and the Italian campaigns when they do so. I am in a mild state of disbelief that the Japanese under your command could do so in 1941.

I’m pointing out the fleet train attached to the IJN merchant marine. It cannot be described in the way you wish it to be.

No, I think you are wishing it to be, so this scenario is even remotely plausible/possible.

Also, do rest assured that the IJN didn’t conduct invasions in 1941 upon the basis of what the USN would do in 1944. If this were the standard, then there wouldn't have been a war.

No , there just won't be a Japanese 3 division invasion on Wa-ki-ki beach in 1941.

What IJA units are you thinking participated in the 1st attack on Wake?

Well of course I thought you would use the SNLF during this Tinkerbull operation. Since you don't, I suppose we will now have to exclude the entire USMC and perhaps all the beachmaster units when it come to discussing the comparative potential success of similar sized US amphibious assaults. Amphibious Landings are a somewhat different critter.

. While it may be true that these operations were “slipshod” in comparison to USMC practice that didn't exist yet,

Yes , but somehow in this scernario the Japanese ARMY? on Dec 1941 are less slip-shod than in later operations and more capable than the USMC was in 1944 when it comes to an amphibious assault.

At Corregidor an IJA division (4th) attacked the fort over the beach, took out the 4th USMC Regiment and then captured the garrison of 11,000 men in 24 hours, didn’t they?

It helps when you can use land base seige artillery and the field artillery of an entire Japanese ARMY to bombard a small island for a FEW MONTHS, daily. And if the garrision has not had much to eat for as many months , And if that GARRISION is convieniently counted, just so it looks good for posting, to include evacuated wounded and sick soldiers from Bataan and civilian refugees to reach an absurd figure of 11,000.

it is not true that the IJA believed itself incapable of conducting them.

Still missing the difference between a landing and an assault. The Japanese were not blind to this difference. Which is why they never realistically planned to invade HI/OAHU especially in "pre-war" planning which is where this operation starts,

AND ENDS.

Chris

[ChristopherPerrien]

I would just like to point out however, that even WITH the benefit of all of the COMINT that you claim from this source historically, the Americans, British and Dutch STILL got their butts kicked by the Japanese in the early war period.

Whose talking COMINT for discovering this invasion , It is discovered by SIGINT AND HUMINT. Historically, Admiral Hart said these assets(sigint/humint) were only off by 18 hours in predicting the attack on PI. Even this interval is perhaps explained by the difference of the attack hour on HI and the attack on PI. I have to look into this "18 hour" comment of his more. Adm. Hart was commander of the Far Eastern(PI) fleet. (2Ca's? 4DD's? IIRC?)

Also and I don't mean to be disparaging , but I dislike the comparision of US forces in Hawaii with British Dutch or American COLONIAL forces elsewhere. Besides, all those areas are far closer to Japan. Plus, the regimental sized US combat force, in PI(10,000 men) along with 5000 rear echelon and 5000 Coast artillery guys were led by star-gazing, "gone native", traitor( Dugout Doug). True there were about 10000 PI "Scouts", who probably deserve to be classed better than colonial/native/miltia, however they still lacked the firepower/equipment and some of the org. advantages of US regular army.

Besides I think US forces in PI deserve to be labelled as "starved out" rather than "butt kicked" as it took along along time for them to surrender. And in a different light, discounting the short duration of the Wake battle, no-one talks about the Japanese kicking butt on Wake Island either.

Why is it that you believe that the defense of Hawaii would have been any different had those islands been Japan's objective of choice

Because I see the mountains of difference between the these islands and the battles that were fought there or could have been fought in/around Hawaii. Plus the DISTANCE problem make it an unclimable "Nitaka". Put Oahu with artillery/flying range of Honshu I might agree with you.

Your source CLEARLY indicates that the IJN messages intercepted by the US that WOULD have revealed Japan's historical intentions were NOT decoded until 1946-47. Had those targets included Hawaii INSTEAD of the Philipines it still would have been 1946-47 (or maybe later) before those same messages were decoded. ?

As I said COMINT was not necessary to stop/discover this raid.Comint paid dividends a few months later. Although reading the Purple/Red codes did help the Humint piture somewhat.. Only SIGINT/Humint was required to sot the various Jap invasion ops and historically it ,was effective in recognizing all the other ops except for Plan Z, the Japanese lauched. In short Sigint, was tracking the invasion forces. Code breaking- Comint was not necessary.

Traffic analysis obviously could have been used to indicate where Japanese forces WERE based, WERE concentrated and WERE loading but since the actual message contents could NOT be read at the time, that DOESN'T indicate just WHERE they have been ordered to invade, does it

This is pure Humint based on the relevant sigint. Countries don't move their most mobile 3 divisions or their entire navy just to mount a deception or just to do it. Sheer economics precludes from doing so.

Hawaii DID receive not one, not two but three WAR WARNINGS from Washington thru the month of November and STILL got the stuffing knocked out of it, so what makes you think that a fourth or fifth would have made much of a difference ?

Still using the excuse of the Pearl Harbor AIR-RAID. Fine, destroy every airplane and sink every US ship on Dec7 1941, still the Japanese can't invade OAHU. KNOW WHY?

Because 3 Jap divisions attacking against two US Divisions won't win . Use the PI excuse of comparing a Japanese ARMY(5-6 divs?) against to a US REGIMENT(1/2 div) if you like. They had no ships,subs, or planes either after the few days, and it ONLY took the Japanese 6 MONTHS to "kick their ass" as you say.

Personally, I agree with YOU in that allowing US 24th & 25th division defenders time to deploy to their beachfront (historically the first US infantry units were in their trucks & rolling from Schofield by 0930) defensive positions will GREATLY increase both the duration of the campaign AND the numbers of Japanese casualties (not that the IJA is all that concerned with casualty totals as long as the mission is acheived). I HAVE engaged Glenn in numerous and lengthy (off thread) discussions wrt this point, but, so far I have been unable to convince him of the wisdom of my point.

Duration of the campaign and number of casualties is vital in this HI invasion , the Japanese can't support a long term "seige" out in the middle of the Pacific.

Mostly because he believes that attempting to bring a Japanese invaison force LARGE enough to survive, ashore on Dec.7'41 will cause a LOSS of surprise and result in US defenders manning the beaches anyway

He is absolutely right , however by doing so he dismisses "suprise" (the first and most important/decisive principle in WAR ( according to some fools like Fuller , Clauswitz,Yamamoto, Me, et al.) as being irrelevant to the success of this amphibious assault. I would conceed that suprise might not matter decisively for the initial AIr attack , but we are talking an amphibious assault here and a lack of suprise in that op will have lots of bodies washing up on shore and in this case a total chaotic hell of a tiny "beach-head" if it even gets that far.

Chris

I do believe that Glenn's forces include an IJA artillery formation of some 100+ heavy guns so he HAS taken steps to address this issue in his invasion plan.

He did, but IIRC, his reasoning and data are pretty flimsy in this field and his wording betrays a lack of conviction or a "doubt" of the feasibility that the Japanese could land those guns and the ammo and support to use them. Perhaps I'll go back and look at this. Plus the Japanese probably had the worst artillery support capabilty/doctrine of any army in WWII. Although maybe the Italians or somebody way down the line might have rated worse, I don't know much about the art. of the smaller armies.

Still it doesn't matter. Even using the PI debacle , the Japnese shelled the Hell out of Corregidor for months and had total naval and air-superiority also. Here the Japanese don't have "months" or that much ammo or that many guns, or that many troops, against two fairly equipped US divisions, closer to our home than there's.

[ChristopherPerrien]

All my talk of SIGINT COMINT AND HUMINT , now has me wondering about what the Japanese would have noticed with their own SIGINT of US movements in the event of them putting this Tinkerbell plan into motion. This thinking goes into the most mysterious and still classified area of WWII study, the deceptions run by the United States. Ever wonder why the Japanese thought there were still 5 carriers in the Pacific(4 at HI).? Their sigint was not much less efficient than the US/Allies.

And if the US was running a SIGINT deception BEFORE Dec 7 1941 WHY???????????

Just a "conspiracy" teaser for a future topic on the Intelligence War , I need to do quite a bit more research/reading before I go there

Chris

[robdab]

Chris,
Whether it be sigint, humint or comint, you have yet to address my basic question in this regard, which is ... Even with ALL of the intelligence (from whatever source(s)) that you claim was gathered by the US, before the outbreak of the Pacific War, why is it that the Allies were completely unable to stop almost the entire timetable of Japanese advances, over a broad front of thousands of sea miles ? (Other than Wake #1 that is, where 450 dug-in US Marines repulsed some 427 Japanese landing troops the first time around. And corrected that a few short weeks later with Wake #2 IIRC). It seems to me that having all of this intel.(from whatever source), didn't really matter 'a tinker's damn'.

And still wouldn't have if Hawaii had been one of Japan's objestives, instead.

Yes, I suppose that you can claim that ALL of those 'COLONIAL' troops were not as good (trained, motivated,awake) as the US regulars on Oahu but I'm not seeing even any suggestions of 'proof' via your listing of sources that support your opinion of their superiority.

Certainly, history records that General Short's leadership of the US Army units on Oahu was very 'poor' and very similar to that provided by 'Bugout Doug'. "Asleep at the wheel" also in spite of all of the intelligence that you claim was gathered by the US before the war began ? Apparently useless as it either didn't get to the officers who needed it OR was ignored if it did ? The WW2 history of the PI does offer 'proof' that the US regulars (and their supporting colonials) there were completely outclassed by the Japanese forces thrown at them. Yes, it took many months to finally force the surrender of the 'locked up in fortresses' US garissons there but really, when you look at it, it only took a few short weeks for the Japanese to kick the US defenders back into those fortress areas, seal them off from the outside world and then takeover the vast majority of an island group that was some 113 TIMES AS Large as is Oahu. There was NO need for the Japanese to rush to overun those isolated fortresses and take massive casualties in doing so when starvation would do the job for them. Quite bright of them, I think.

My viewpoint is that the ENTIRE peacetime US Army was probably very 'soft' by 1941. Other than the USMC invading several tiny (mostly defenceless) Central American nations in support of the Dole Pineapple Company, Chiquita Bananas and various other US agricultural giants, they hadn't fought a real war since the end of 1918, some 23 YEARS before. And based on General Short's and Admiral Kimmel's numerous pleas to Washington, we know that these two divisions (and most of Hawaii's other defenders) were both sadly understrength and under-equipped with modern weapons systems.

In contrast, Japan's IJA/IJN troops had been training, fighting, dying and honing their combat skills in China for nearly a decade by late 1941. Why would you suppose that those US regular troops, well used to enjoying the Oahu sunshine and cool tropical breezes, would be able to stand toe-to-toe against that kind of recently experienced (and proven to be utterly ruthless), fighting machine ? Other than just the fact that they were AMERICANS, I mean ? ESPECIALLY in Glenn's context of their morale having just taken the TWIN massive surprise HITS of seeing the USAAF wiped from their skies by the Kido Butai's fliers and the survivors of their much respected US Pacific Fleet bombed, shelled, burned and otherwise chased all the way back to the US west coast. And all of this after reading, for years, in their newspapers that Oahu was the strongest fortress in the entire Pacific region. So strong that it was 'un-attackable' ? Not.

Since it was you that first played the 'Colonials' card I would also remind you that a fairly large portion of the US defenders on Oahu were also 'native' formations raised on those very same islands. With a high proportion of those troops having Japanese ancestry themselves. Not surprising when you consider that this was true of about 37% of Hawaii's entire population of the day. Yes, historical records show absolutely ZERO acts of sabotage ocuuring on Hawaii (remember that starting late on Dec.7'41 the FBI arrested and held without charge for years, some 1,500 Hawaiian residents deemed to be 'security risks') during WW2 but I suspect that had Japan actually planned to invade Hawaii, some surprise 'fifth column' sabotage COULD have been arranged. Imagine the US combat capable manpower drain to guard EVERY rear area road & rail bridge, miles of railway track & all of the rolling stock, miles of powerline pylons, ports, miles of overhead telephone lines & poles, radar stations, radio towers, airfields, power plants, telephone exchanges, pipelines, ammunition depots, hospitals, water treatment plants, etc., etc., etc. if even a FEW demolition charges/bombs had gone off ? The list of potential sabotage targets was nearly endless. One highway of the day passed less than 20' from one of the huge oil tanks that was part of the tank farm near the PH submarine base. Even without explosives, many of Oahu's steep mountain roads could easily have been blocked for days merely by triggering a rockfall/landslide that would later appear to be natural in origin.

Don't forget that one entire US regiment was stripped from one of these US divisions just weeks before Dec.7'41 and its various battalions sent to (finally) garrisson some of the other Hawaiian Islands, thus further weakening Oahu's defenses. Both of these US divisions were still in the MIDST of an October 1941 ordered re-organization as well. Talk about 'changing streams in mid-horse' (or should that be 'horses in mid-stream' ?) !

Also, lets not just gloss over the US NEED to feed/water/protect all of those American civilians on Oahu. It would be hard to concentrate on setting up a good defensive lines while you are herding tens of thousands of combat refugees to safer locals. We can never know what proportions of Oahu's 1941 Japanese population would have seen IJA/IJN invaders as enemies OR welcomed/aided them as liberators but the provision of ANY such local knowledge would have been very harmfull to US defense abilities.

Two (and a half) full strength, COMBAT EXPERIENCED Japanese divisions, with massive amounts of artillery, Kido Butai and Combined Fleet help (not to mention land-based Japanese air flying from other captured Hawaiian Island airfilelds) vs two understrength, peacetime soft, surprised, bombed, shelled, strafed, isolated and just re-organized US divisions burdened with some 265,000 civilians (some with questionable loyalties ?) doesn't sound like all that long/tough of an Oahu fight to me. Please provide some sources that I can read to prove myself to be mistaken.

But we'll never know for sure, just how it would have played out. The best that we can say now is, "Most probably ......."

[glenn239]

And if the US was running a SIGINT deception BEFORE Dec 7 1941 WHY???????????

Just as a polite request, would it possible to keep the nutbar PH conspiracy stuff off my thread?

I have been using a figure of 200 ships somehow in this ATL this is in an error….Needless to say 95 ships (which includes the warships too) is an amazing figure to land 3 divisions and support an amphibious landing(correction ASSAULT) 2000

Chris, it’s becoming painfully evident from your comments that you haven’t bothered reading the thread. Check the OOB posting.

It helps when you can use land base seige artillery and the field artillery of an entire Japanese ARMY to bombard a small island for a FEW MONTHS, daily…..

I provided in the thread the firepower employed by the IJA on Corregidor and by the USN upon Okinawa. At Okinawa the USN alone (ie, not including the USMC or US Army), delivered 1,100,000 25lbr equivalents onto Japanese positions. At the Philippines (ie, including the entire campaign), the IJA used about 120,000 25lbr equivalents of artillery shells. Only about ½ or so (75,000) were used against Corregidor. Note that the weight of fire against the Japanese at Okinawa was about 14-15 times greater, and that Corregidor’s defenses were as resistant or more to shellfire.

Also, with respect to Corregidor, do recall that the attacking force took several thousand casualties in what was a severe battle.

He did, but IIRC, his reasoning and data are pretty flimsy in this field and his wording betrays a lack of conviction or a "doubt" of the feasibility that the Japanese could land those guns and the ammo and support to use them. Perhaps I'll go back and look at this. Plus the Japanese probably had the worst artillery support capabilty/doctrine of any army in WWII.

IJA artillery doctrine was poor, and this would effect performance with respect to on-time fire requests (ie, 6 hours or more).

With respect to getting an IJA artillery regiment onto Oahu, it might not be possible to land the entire unit in one operation over the beach. Which is another reason why the Japanese occupy Maui and Molokai and Kauai, of course.

Yes, I suppose that you can claim that ALL of those 'COLONIAL' troops were not as good (trained, motivated,awake) as the US regulars on Oahu but I'm not seeing even any suggestions of 'proof' via your listing of sources that support your opinion of their superiority.

24th and 25th ID became very good divisions during the war. Both were green in December 1941, but had the “right stuff” to learn their trade quickly. Would that be good enough against the IJA? Maybe, maybe not.

There was NO need for the Japanese to rush to overun those isolated fortresses and take massive casualties in doing so when starvation would do the job for them. Quite bright of them, I think.

Having taken the air bases near Luzon, the Japanese decided to then to essentially bypass the Philippines for the time being, leading to the extraction of the 48th Infantry Division from the campaign.

Three full strength, COMBAT EXPERIENCED Japanese divisions, with massive amounts of Kido Butai and Combined Fleet help vs two understrength, peacetime soft, surprised, bombed, shelled, strafed and isolated US divisions burdened with almost 250,000 civilians (some with questionable loyalties ?) doesn't sound like all that long/tough of a fight to me.

Don’t forget that 4th, 21st and a couple of 2nd rate units are also available if the issue were in doubt. The key feature of a battle at Oahu is establishing ascendancy in air power via the other islands and the IJA artillery regiment, so that the Americans can’t re-establish theirs on Oahu. This forces the USN to rely upon carrier airpower, which is subject to all the same disadvantages that make IJN carrier airpower so brittle.

[robdab]

For anyone interested, a copy of John J. Stephan's book "Hawaii Under The Rising Sun" closes on ebay in about a day and a half. Item #170115302901 at http://www.ebay.com

No connection to vendor etc., etc.,

[salek]

Harry Turtledove, one of my favorite alternative history writers, has written a novel (a pair of books as one story) about the invasion and life in occupied Hawaii.
"Days of Infamy" and "End of the Beginning" are the matched pair in order.
He examines the food problem, POW treatment, and comfort women heavily in his novel.

I recommend them as a (non-technical) human condition study to go along with this very technical post.

I was amazed by the amount of information about the weapons defending Oahu. Could somebody please point me to a post about the coastal defense weapons of Texas? My Father tells me that in 1948 children (he was five years old) could crawl onto the 14" BLRs emplaced at Galveston. He said that he remembers big chains on the mechanisms, but otherwise, he climbed on them. Now, only the open pits remain.

Strength and Honor, Y'all
Salek

[robdab]

,,, can be found via the Coastal Defense Study Group at http://www.cdsg.org

I've also had lots of luck with simple google searches.

Turtledove is not regarded with much respect in the "what if Japan had invaded Hawaii" circles that I have encountered. While his (apparently many) alternative history novels have definite mass market appeal, they are often short on the technical detail needed to make them believable past anything more than a quick read. Good for entertainment but not able to offer any level of convincing "proof" that their contents MIGHT have actually happened, had Japan made different choices

[glenn239]

I was amazed by the amount of information about the weapons defending Oahu. Could somebody please point me to a post about the coastal defense weapons of Texas?

Nothing specific, but when poking around looking for information, I too was taken aback by the depth of defenses built in North America. Quite frankly, I didn't entirely see the point to it, unless the Royal Navy somehow entered the equation.

Turtledove is not regarded with much respect in the "what if Japan had invaded Hawaii" circles that I have encountered. While his (apparently many) alternative history novels have definite mass market appeal, they are often short on the technical detail needed to make them believable past anything more than a quick read.

In all fairness to Harry, invading Hawaii is a real bugger that defies an easy answer. IMO, had the outlying islands had even 3,000-4,000 men apiece, an attack could not have occured.

[Troy Tempest]

Top effort Glen239! It took a long time to read but I found it well worth the time mate!

[glenn239]

Thanks. Rob and I are discussing things offline, and when I'm ready, there will be an 'improved' version posted on another site.

[Carl Schwamberger]

Nothing specific, but when poking around looking for information, I too was taken aback by the depth of defenses built in North America. Quite frankly, I didn't entirely see the point to it, unless the Royal Navy somehow entered the equation.

Paranoia, politicians advancing pork barrel projects, and a tiny bit a prudence against suspected but unproven enemy capabilities. 99% of the first two?

The capture of some German agents on the Long Island beach, a submarine attack on a Venzuelian oil refinery, and the Japanese sub attack on the West Coast all fed the hysteria factor in 1942. From 1939 the defense fianance appropriations had to include allocations for lots of miitary construction for the Congressmen to brag about baack home.

Last, no one was willing to look stupid if a Japanese raid had materialized and there was not so much as a MG posted on the beach. We all know now how unlikely that was. But, in the 1940s the Axis had suprised the Allied leaders more than a few times with "impossibilities".

A waste yes, but then 99/9% of most militay efforts are wasted.