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Given the total Japanese resources if they do invade Hawaii on Dec 7/8 what else does not get attacked?
Malaysia? The Philippines?
How many troops and transports would be needed for a Dec 7th attack?
More than they could afford. Yamamoto was in favour of a direct attack from before the war, but he was constantly overruled. Finally, in the planning stages for Midway, it was the army who gave the Japanese one of the few reality checks in their high command. They calculated, that they would need 45000 troops for the invasion (a gross underestimate) and 70 trtansports per month just to keep the garrison supplied. This goes far beyond any logistic capability ever possessed.
As the midway operation progressed, the Japanese came to see the blockade and starvation of Hawaii as possible bargaining chip at the expected peace talks. We have this notion that the Japanese were not prepared to use their submarines and ships in anti shipping roles. this is incorrect. They were quite prepared to use them, but they gave them other priorities as well. In the aftermath of midway, once the USN had been removed from the equation, the Japanese intended to apply a tight blockade of the HI. Faced with starvation for a sizable chink of their population, the Japanese expected the US to sue for peace fairly quickly.
I think these appraisals are totally unrealistic. I dont think the US would give up nearly so easily. If Midway had gone the Japanese way it would have taken longer for the US, but the result can hardly be in doubt.
OK, I'll throw this out... Delay the attack on the PI/Big Mac, those 34 B-17s don't pose a real threat at this stage of the US Build up and half are historically wiped out by the Tainan airgroup in any case on the first day, as well as a significant fraction of the defending fighter force. Small scale operations in preparation for the ultimate PI invasion, like seizing the northern small island airstrip on Batan Island could proceed. Yes, PI would be a thorn in the side of IJ during the time it took to reorganize for the PI invasion. But I expect, the USA's overall PI defensive capability is unlikely to have improved significantly during that time.
Organize and use the forces ~70 transports and associated troops to invade Oahu. The USN CVs don't yet represent a real significant threat to the operation and are likely to be eliminated piecemeal during the operation. The three USN CVs wouldn't be able to execute coordinated attacks and the sought-for decisive sea battle would have occurred in the waters around Oahu at the very start of WW2. IMHO, early loss of Lex, Sara and Enterprise would be highly probable (during their attempt to find and engage Kido Butai) and severely cripple subsequent US operations.
The question in my mind is whether a commando-style raid (with a significant force) with the purpose of destroying local military support infrastructure (harbors power plants, fuel depots, ammo supplies) would have been better than an all-out occupation of the island.
Pars to your knowledge has anyone every tried to game such a scenario?
Containment of the PI was achieved fairly easily, and Macs insistence on a forward defence flew in the face of US military planning that stretched back at least 20 years. The Americans always planned to retreat to their fortress hideouts and await relief from the US fleet as it fought its way across the central Pacific with relief. The B-17s, the forward defences, even the arming of the filipino army were all really froth and bubble advocated by Mac and his supporters that in thge end came to nothing. The intent was to fight a decisive battle against japan, somewhere in the vicinity of Guam, win that battle and then press on to break the PI blockade.
All this was known or surmised by the IJN. What really alarmed them was the relocation of the Pacific Fleet to Pearl Harbour in 1940. If the US had remained centred around San Diego, as pre-war planners had wanted, Pearl Harbour would never have happened. as part of the administrations "big stick" policy toward Japanese aggression, the insistence in pushing the fleet forward prevailed. But the USN in particular remained jittery about this dangerous deployment....from January 1940 to the actual attack there were, from memory no less than 17 false alarms as to Japanese attacks. The Japanese were known and expected for surprise attacks, though inexplicably thye USN high command seem genuinely surpised that Pearl was, in the finish the focus of that main effort.
The Japanese traditional planning was also somewhat deviated by Yamamotos plan. the Japanese planned to attrition the US battlefleet as it advanced across the pacific, using a mix of submarines (which were designed for this very purpose....a surface speed of 24 knots compared to the US battlefleets best speed of 21 knots), and then commit their own battlefeelt also in the vicinity of guam, but a reduced strenfgth USN would lose because of the attrition it suffered....according to the Japanese.
Pearl harbour was promoted by Yamamoto because he wanted to strike preemptively at the USN, but the focus of Japanese operation was always to get control of the strategic resources quickly and a big part of that was securing the PI. diverting troops away from the PI was possible but was counter to the fundamental Japanese strategy. moreover, it was not enough effort. 1.7 divs were committed to the capture of the PI, with a further 2 sivs, earmarked for the conquest of the NEI held back in reserve at okinawa and Palau under the control of 16A. 16A was held back for two reasons, lack of shipping, and also because the level of resisitance in the PI was not fully known. Diverting all thye shipping and all the troops for the right flank attacks south....the NEI and the PI operations, would have delivered about 4 divs in total, and about half the required transpoirts. still not enough to have a crack at the PI. And they knew it . Not only would japan be abandoning their strategic priorities, they would also be likley to fail, even by their own standards of narrow margins.
A better optioon for the Jpanese might have been not to attack at Pearl at all. If the Pacific fleet had been allowed to gather its strength andf advanace across the pacific, it is likley, in my opinion that it would have suffered a huge defeat anyway. It wasnt ready to tackle the japanese in December 1941, and would have sallied forth for combat and gotten itself destroyed at sea, for little loss to the Japanese. this includes their carriers IMO, which in December were just to lightly equipped to be able to mix it with the KB at all really.
As indicated above, even with the entire right wing of the Japanese attack abandoned, there still was not enough transport available to tackle this attack.
Hard to see how any surface fleet of any size could approach the PI without giving away their position. give the US forces even a half days alert time and the situation changes completely in my opinion.
I did once or 5 times with the WITP system. We gave the Japanese surpise advantages, even stripped out the japanese economy by raping its shipping reserves . We could not crack the PI landward ddefences except for one attempt, which ended as a bloodbath for both sides. US reinforcements were rushed to the islands, and eventually the Japanese attacks were defeated.
just a game i guess.
If the Japanese conducted a multiple-point landing operation while the first/second attack waves were hitting Pearl, this would allow them to get ashore unchallenged. Instead of Nagumo cancelling the third attack wave, continue the attacks (perhaps alternate approach patterns) until the landing forces report a secure foothold.
The element of surprise is absolutely key in this situation, however, as historically happened, the Japanese were able to close their taskforce within striking range unchallenged and delivered a series of attacks while everyone on Oahu were enjoying the start of a relaxed Sunday.A surprise simultaneous air/land attack would be mandatory for this to be successful. The US had about 43000 Army troops and an unknown Navy and Marine forces available for combat, 99 P-40s, and 53 P-36/P-26s, a strong force, if alerted. Add to that a small island with some very tough terrain features and Hawaii would be a formidable target. To closely approach Hawaii with an invasion fleet would have dangerously exposed the attack to early detection with considerable ramifications, making this option very risky.
But one might say that only underscores the theory they didn't appreciate its true significance, at the time, not until much later.Given the total Japanese resources if they do invade Hawaii on Dec 7/8 what else does not get attacked?
Malaysia? The Philippines?
How many troops and transports would be needed for a Dec 7th attack?
The element of surprise is absolutely key in this situation, however, as historically happened, the Japanese were able to close their taskforce within striking range unchallenged and delivered a series of attacks while everyone on Oahu were enjoying the start of a relaxed Sunday.
With this in mind, assault forces closing under the cover of the night/dawn to coincide their approach during the air attacks (on or before 7:00 a.m. as originally occurred) would certainly offer positive results. The bulk of U.S. forces were in and around the vicinity of Pearl with a few auxillary fields and air stations about the island. These smaller fields did not have a large amount of first line aircraft that would have been able to muster more than token resistance.
The Japanese multiple landing zones would most likely be along the western, northern and eastern shorelines and the IJA was no strangers to rough tropical terrain.
If Nagumo follows through with the three attack waves that were planned, then carry on with follow up strikes while the battleship/cruiser force closes to offer close support while the U.S. fleet was being neutralized, the situation would be very difficult for the U.S. forces.
As poor as communications actually were, it seems to me that trying to muster defenses against Japanese landing forces to the north, east and west would have been nearly impossible, especially while everyone was keeping their heads down during the initial air attacks.
It's certainly interesting to think about.
Well, certainly, but not entirely unforeseen. Pearl had all our shipbuilding capability. Look at how quickly we were able to patch up the Yorktown. We're otherwise going to San Diego for that.The PI re4presented a major threat to japanese lines of communication to the south. the chief threat were the 29 submarines they had stationed there. as luck would have it, an air raid early on on the Cavite Navy yard destroyed the Tordeo stocks being held there, but that cannot be relied upon as a certainty . the japanese needed to get ashore early and capture these forward bases in order to deal with the threat that they posed. All this talk of containment, bypassing whgat was the major strongpoint for the US in the far east, is just trying to take advantage of perfect hindsight after the event
Well, certainly, but not entirely unforeseen. Pearl had all our shipbuilding capability. Look at how quickly we were able to patch up the Yorktown. We're otherwise going to San Diego for that.
I'm a little dark on the actual campaign in the Philippines. I do understand why the Japanese needed that, though, given their plans in that area. Hawaii would have taken a lot out of them, too, I don't think anybody is doubting that.
Well sure, hindsight can offer a good view of events, but it's interesting to consider the alternatives once in a while.
Nagumo cancelled the third strike at Pearl because he did not know where the U.S. carriers were. But then again, the attack at Pearl was successful because no one knew the Japanese were on their way.
Alot of operations or otherwise significent events never happened because of the lack of intel or acting on the side of caution when we can look back and say "what was he thinking?"
But, like I mentioned, it's an entertaining diversion to look at the big picture and consider how things would have changed had one or another events happened differently.
That's right, Crow, the repair yards. My point is though that alone made Hawaii more integral to the maintenance of our presence there than the Philippines. The Philippines was strategic to what the Japanese needed to get done in that South West Pacific region. That's why they took their eyes off Pearl, after the plundering. Pearl more than anything kept the US in the fight. They'd have taken out that sanctuary, we'd have been in trouble. We're maybe not throwing in the towel, but they got our attention. Because they never fully grasped that, that bought us time. Take out Pearl, we're seven or eight days away from that South West Pacific region, and by the time we get there, we're out of gas, and that's all provided we get by an occupied Hawaii, first. That's a lot to ask, even of a big nation. We can recruit and train and build and dress up until we're dizzy. Get it to the dance floor. How are we going to do that? There's nothing there. Giving the US time, that's what leaving Pearl meant. In short, it's what did the Japanese in.You probably mean ship repair capability vice building. I think anything major whether building or repair took place in stateside ports. All the BBs that would eventually become operational again were ultimately made sea worthy and sent back to the states for major repair.
AFAIK, the need to take the PI was due to the US military presence there and the air and naval bases from which it could act to sever the lines of communication and marine transport between the NEI and the home islands.
The forward basing of the Pac Fleet in PH moved it closer to the PI bases which already possessed a USN presence in the form of a heavy and a light cruiser a ~dozen DDs and a fair number of submarines. Moreover, the progressive B-17 buildup in the PI was perceived to present a similar threat to both interdict the sea lines of comm and IJ Taiwanese bases.
Good books on the PI campaign and well worth reading are Bartsch's books: Doomed at the Start which I've read and December 8, 1941 Macarthur's Pearl Harbor which I haven't. Also Days of Infamy by Costello. I recently purchased Fortnight of Infamy by Burton about the collapse of allied air power in the Pacific in just the first two weeks of the war. But haven't had a chance to read it yet.
late edit: changed 'sea-safe' to 'sea worthy'… what am I a fr*cken land lubber?