Japanese invasion of Hawaii?

Cadendish

Banned
What if The Japanese empire after Pearl Harbor had attempted to invade Hawaii?
 
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Not enough warships or transports available.
Not enough troops available to take Oahu, let alone the other islands.
The goal of the war is to take the Southern Resource Area (Dutch East Indies oil fields), taking Hawaii does not help that goal.

This is a What If that only works if you look at the Pearl Harbor strike in isolation. The reality is that Pearl Harbor was a diversion and one shot strike to protect the Japanese left flank in the attacks on Malaya and the DEI. The same with the attacks on the Philippines.

Invading Oahu can only hurt the Japanese.
 
What if The Japanese empire after Pearl Harbor had attempted to invade Hawaii?

It gets curbstomped. The Japanese barely managed to pull off the Pearl Harbor raid, and stretched their resources to the limit. Japan would have had to commit most of it's navy and a lot of troops to such an adventure, which would have meant stripping them from military commitments elsewhere. In particular, it would have meant no invasion of the Dutch East Indies, AKA the "Southern Resource Area", which was their main goal, as well as the invasions of British colonies in Southeast Asia. The Pearl Harbor raid was in large part carried out to keep the US Navy from interfering in these conquests, and capturing the Southern Resource Area in particular was absolutely vital to Japanese plans, so it would have made little sense to cancel these conquests and occupy Hawaii instead, especially since there is no way the Japanese could hold it long-term as resupplying it would stretch Japan's logistical capabilities to breaking point.
 
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Basically, logistics.

Japan already overextended heavily during Pearl Harbor, and their CVs were at the limit of their effective range. Not to mention the US would probably be scrambling troops and ships with their much less hampered supply lines to defend Hawaii.

As previous poster(s) have already stated, Japan's main goal was the conquest of the British Colonies and Dutch East Indies. Any attack on Hawaii would inevitably mean less forces and more postponement. Since the resources from these conquests were needed to continue running the war machine, any delay saps the strength of the Japanese military.

And even if they were to, by some miracle, take Hawaii, how would they hold it for any meaningful amount of time? It would be a priority for the US to retake, US submarines would be focusing the supply ships traveling the very long trip to Hawaii, further hampering the supply lines, and there would also probably be a bunch of guerrilla units wrecking havoc on the Japanese garrison. Not to mention that an occupation inevitably means less troops for the invasion of the lands they ACTUALLY need, like the Philippines and Singapore.
 
Japan invading Hawaii IMHO is the Pacific's version of Unmentionable Sea Mammal. Landing troops is one thing but holding the island (or islands) for any length of time is completely out of the question
 

SsgtC

Banned
Japan invading Hawaii IMHO is the Pacific's version of Unmentionable Sea Mammal. Landing troops is one thing but holding the island (or islands) for any length of time is completely out of the question
Even landing troops on a hit and run raid is seriously stretching things to the point that the USM actually starts to sounds plausible
 
One thing that you learn to appreciate from studying the first six months of the Pacific War was just how much of a shoe string the Japanese operated on when they did what they actually did. A big part of the reason ATLs focusing on the early Pacific War are so popular (TLs by me, fester, Galveston Bay, Cal Bear, johnboy to name a few) is that there are so many places where even a slightly more competent performance on the part of the Allies can really throw sand in the gears of the Japanese operation.

Taking a massive convoy of transports loaded with at a minimum three divisions of troops and all of their supplies along with all of the escorts to include enough sea based air power to support them and a fleet train to sustain an extended campaign is several bridges too far.
 
One thing that you learn to appreciate from studying the first six months of the Pacific War was just how much of a shoe string the Japanese operated on when they did what they actually did. A big part of the reason ATLs focusing on the early Pacific War are so popular (TLs by me, fester, Galveston Bay, Cal Bear, johnboy to name a few) is that there are so many places where even a slightly more competent performance on the part of the Allies can really throw sand in the gears of the Japanese operation.

Taking a massive convoy of transports loaded with at a minimum three divisions of troops and all of their supplies along with all of the escorts to include enough sea based air power to support them and a fleet train to sustain an extended campaign is several bridges too far.

Order of Battle USN; Pearl Harbor; 7 December 1941

Order of Battle US Army: Pearl Harbor; 7 December 1941

Good grief. The attack on Midway included over 60% of the entire IJN first line strength, burned up 2 months peacetime operations supply of fuel oil and killed the Kido Butai; completely dislocating and ruining the IJN's primary strike arm for a whole two years. (Japanese carrier operations in the Solomon Islands campaign while formidable were a series of organizational ad hockeries, not as formalized as First Air Fleet.) Now someone wants to invade Hawaii on day 1 of the Pacific War?

147,000 armed US Navy, regular army, and marine personnel
15,000 national guardsmen in reserve
Admittedly obsolete, but still present coast artillery defenses... intact coast artillery defenses.

Let's assume Moritake Tanabe has gone stark raving mad, and the rest of Imperial General Headquarters likewise, what are they going to need?

The entire IJN as deployed for Midway, including the Aleutians side show, because they will need close to 400 aircraft and all 10 carriers to achieve aerial mastery over the entire Hawaiian Island chain.

Enough sea-lift to land FIVE divisions with follow on for four more.

How much is that?

At a minimum, one is looking at about:

150 troop transports
20 fleet tankers
at a guess about 400 landing barges
25 ammunition ships
and enough other auxiliaries to double that IJA force.

hawaii.gif


The Japanese would have to pick an island, (Not Oahu, their doctrine was to land adjacent to an enemy stronghold, seize or build airbases, gain air superiority and then conduct an amphibious "nibble them to death" series of operations to scatter, dislocate and disintegrate the local defense by a "death of a thousand small battles" campaign. It would take them time to achieve their desired situation (about 60 days?) ).

Where?

Kauai. Along the north shore. Head for Princeville and Lihu. Size? 2 division assault. Operations corresponding to this? Lingayan Gulf Big Island has to be simultaneous with operations aimed at Hilo along the NE shore. Another two divisions at least. Again as large as Lingayen Gulf. There are not enough ships in the Japanese mercantile fleet to do it, along with just the Philippines and Malaya campaigns. Never mind the Indonesia operations. Where is that 3/4 of a million tonnes of shipping to mount and sustain this operation to come? Where are the 200,000 troops to be found? Where is the 12 months peacetime military supply of fuel oil burned up in 60 days to come?

Logistics.
 
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Years ago I used the old Victory Games Pacific War game (1985) to try and see if an invasion of Hawaii as part of the Pearl Harbor attack was possible. Yes I was forced to work within the construct of the game and its rules and mechanisms but I also permitted myself to use perfect 20/20 hindsight.

It couldn't be done. The logistics, the forces involved, and the time required made it impossible, even when stripping other operations of vital forces. One big problem beyond basic logistics and force allocation was that it was completely dependent on sea based airpower which was at the time (and arguably even now), somewhat fragile in the face of sustained operations. It even required a significant effort on the part of the Japanese to capture forward bases like Midway and Johnston that could be useful forward bases for a future operation or tripwires against future American operations, the second being more likely because any capture of islands like Midway and Johnston would lead to a massive reinforcement of Hawaii.

Like others have said - LOGISTICS, LOGISTICS, LOGISTICS.
 
It would have ended badly for the Japanese 5 times out of 6. If the Japanese got lucky Hawaii would be a devil to supply. Japan would do well to leave a token force, and would be forced to let the population starve (not that they wouldn't have done that anyway.)

I'm trying to get a thread started discussing the ramifications of a failed Japanese Invasion of Hawaii, there's a link in my signature if you're interested. (Hopefully plugging other threads isn't against the rules, if so I apologize.)
 
One thing that you learn to appreciate from studying the first six months of the Pacific War was just how much of a shoe string the Japanese operated on when they did what they actually did. A big part of the reason ATLs focusing on the early Pacific War are so popular (TLs by me, fester, Galveston Bay, Cal Bear, johnboy to name a few) is that there are so many places where even a slightly more competent performance on the part of the Allies can really throw sand in the gears of the Japanese operation.

Taking a massive convoy of transports loaded with at a minimum three divisions of troops and all of their supplies along with all of the escorts to include enough sea based air power to support them and a fleet train to sustain an extended campaign is several bridges too far.
But what a bridge it would be...Fujiyama to Diamonhead...
 
Years ago I used the old Victory Games Pacific War game (1985) to try and see if an invasion of Hawaii as part of the Pearl Harbor attack was possible. Yes I was forced to work within the construct of the game and its rules and mechanisms but I also permitted myself to use perfect 20/20 hindsight.

It couldn't be done. The logistics, the forces involved, and the time required made it impossible, even when stripping other operations of vital forces. One big problem beyond basic logistics and force allocation was that it was completely dependent on sea based airpower which was at the time (and arguably even now), somewhat fragile in the face of sustained operations. It even required a significant effort on the part of the Japanese to capture forward bases like Midway and Johnston that could be useful forward bases for a future operation or tripwires against future American operations, the second being more likely because any capture of islands like Midway and Johnston would lead to a massive reinforcement of Hawaii.

Like others have said - LOGISTICS, LOGISTICS, LOGISTICS.

That game has been on my wishlist for a long time..

pic128087_md.jpg
 
Hello!

Just an aside but.....

Why could not the Japanese land a considerable (But token) force and then hand the islands back to Britain as a "Sorry for denting your stuff in Asia. Here, have these back as a way to make up for it." kind of thing?

Just curious.
 
Hello!

Just an aside but.....

Why could not the Japanese land a considerable (But token) force and then hand the islands back to Britain as a "Sorry for denting your stuff in Asia. Here, have these back as a way to make up for it." kind of thing?

Just curious.

1. The situations in India, Burma and Malaysia are redline, so His Majesty's government is in no mood for jokes.
2. The Americans have just been convinced after a lot of haggling that it is Germany first and the Roosevelt Administration is in no mood for jokes.
3. If the Americans are going to spend a half trillion dollars to recapture a colony they are going to give up in 1946, how will they react to a Japanese attempt to bribe the British with the American crown jewel of the Pacific, which is on its way to statehood?
4. With 1,2,and 3 in play, just what kind of crazy person in London is there, who wants to torque off the Americans?
 
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