A Japanese invasion of Hawaii

[Neilster]

This blog post by historian Nigel Davies involves a Japanese invasion of the Hawaii islands. I'm going to post it in General Discussion but I was wondering what those here thought about it from a MWiF perspective.

https://rethinkinghistory.blogspot.com/ ... 5Rhhm0lXOk

[Centuur]

Nowadays, we know it is important to send US ground units to Pago Pago and Honolulu to get a good defense for those islands. The same goes for example for screening the Italian fleet with FTR cover or not setting up your best units in the Maginot line with France.

On both sides there were a large number of mistakes made. The US believed an attack on Pearl wasn't possible, the Italians believed the port of Taranto was to shallow to use torpedoes and the French believed it was impossible to use tanks in the Ardennes.

The same can be said for the Japanese mistake for not invading the main island is of course a mistake, if one looks back at it from the historical point of view. I believe that there were about 25.000 troops in december 1941 on the main island. Against two battle hardened Japanese divisions with a good invasion plan and being hammered on by a Japanese carrier fleet with air superiority, seeing the US navy in flames from the day before, they would have been demoralized.
So in MWIF terms, this could have been presented by a 1 factor INF division. Of course, the Japanese would have to use the two MAR units (and a losslaking division) to invade, add shore bombardment and ground support. That gives a +9 attack against one unit in mountains.

However, would the US not have send more troops to the Island if Japanese MAR would appear on their doorstep in the Marianas...

[rkr1958]

1. I think the biggest mistake that the Japanese made, specifically Nagumo in the surprise attack on Pearl Harbor, was not going after US oil storage and repair facilities.

2. With respect to a Japanese invasion of Hawaii. I suspect that initially they may have been able to take the island chain; but my opinion is that they didn't posses the logistics to properly defended it. Look at the Aleutians for example.

3. My opinion is that if they had captured the Hawaii islands in late 1941 or early 1942 that we would have launched a major campaign and would have taken Hawaii back by mid 1943. Look at the Solomons for example.

[Centuur]

There is something else to consider too. The US would have needed to replace far more ships (cruisers and destroyers too), because they would not be able to sail out of Pearl into safety, if the Japanese had invaded the island. That's because the port would be blocked by the Japanese Navy.
Merchant shipping in a huge part of the Pacific would also be a lot more difficult for the Allies. Imagine Japanese ships raiding the eastern part of the Pacific. And we all know how the Japanese weren't interested in feeding the population of conquered area's at all. No food for the white people and captured soldiers? No problem. Put them all in prison camps. The only difference between the German and Japanese concentration camps was that in the Japanese ones, there were no gas chambers. They only provided for their own soldiers. Now that simplifies logistics a lot.
And don't forget: with no US ships on the Hawaiian islands, I believe that the Japanese merchant fleet would have far less losses in the first year of the war.
Personally, I believe it would have taken at least two years longer for the US to make it's present felt against the Japanese.

[Courtenay]

I really don't think that the US troops at Pearl Harbor would have been demoralized. They would have been infuriated. Take a look at Wake Island, the only example in the war of coast defenses repelling an amphibious invasion.

Also, the Japanese did not have the logistic capability to sustain a carrier fleet off Pearl. It was all they could do to get in, make a strike, and get back.

Although I did once have a game where an incompetent ally of mine lost Pearl on the surprise impulse. The Wasp got captured. That game did not go well for my side.

[paulderynck]

If they repelled the invasion, how come the Japanese held Wake for the duration of the war?

[michaelbaldur]

also another factor, USA did a Germany first strategy.

if Japan had taken Hawaii, usa would surely have changed it into a Japan first strategy.

it would have meant that the war would have been longer. Usa simply did not have the navy for a Japan first.

the main reason they started with a touch landing, was that I could be done with a limited navy, also the fighting against Italy was done with a limited navy

trying to take Hawaii back in 1942, with a limited navy, would have been suicide, they did not have the carriers to get air superiority over Hawaii and did not have the submarines to blockade it. and the Japanese navy would have been based at hawaii. in the beginning of 1942, Usa had like zero operational battleships.

[Courtenay]

If they repelled the invasion, how come the Japanese held Wake for the duration of the war?

Because after their first try ended in a disastrous failure, the Japanese gathered more forces and tried again two weeks later with a much stronger force. That second attack succeeded.

[DQ2004]

The original article makes a good case for Japan invading the island of Oahu rather than wasting time with just the air attack.
Whilst there's no doubt it would have been a bigger ask, and would have delayed some of Japan's assaults in South East Asia, they *could* have done it if they'd really wanted to. They solved the logistics of launching the strike (against the expectation of the US), they could have solved the bigger problems of a surprise invasion too.

In game terms, it makes a lot of sense for the Japanese player. The effect of a surprise attack impulse ground invasion has the same, if not a more significant effect on the USN fleet there -because the ships are treated as though they are disorganised, and have a good chance of being destroyed, or even a 10% chance of being captured!
With at least ten ships in harbour, not only might Japan capture some ships, most embarrassing for the US player, if they deploy their ships around the islands correctly, they can intercept the fleeing fleet (!) as it rebases, and that could well add, well, more injury to injury.

Obviously the Japanese player MUST isolate Pearl Harbor prior to the ground invasion, and its carrier planes are best employed on ground strikes to disorganise the ground unit/s there. But they will have only a 10% chance of achieving that, and Japan may still end up requiring a good roll to take the island.
But if they succeed, the benefit is enormous, there's no doubt about it.
The US fleet will likely be even more devastated than it was historically, and now they don't even have a good base from which to mount counter-attacks. Instead, Japan now has that base to use against them, and to keep their offensive going in the South Pacific and as a barrier to US counter attacks (and any attempts to defend the South Pacific and Australia).

In reality if it had happened it might have delayed Japan's eventual defeat by another year or perhaps more.
In game terms it may well mean Japan successfully holds its gains in the Pacific to the end of Jul/Aug 1945.

[Orm]

They had a long discussion about whether the Japanese could do it, or not, on the General Forum. The consensus was that the Japanese could not have launched a successful invasion on Oahu during the surprise. They could probably not even have tried to do so. But if they did it would fail and shorten the war. Beware, it is a 47 pages long discussion. https://www.matrixgames.com/forums/view ... f5be2b9386

Whether they can in MWIF, or not, is a completely different discussion.

[Orm]

Not sure you can guarantee that there are 10 US ships in Pearl Harbour during a surprise invasion. US could, for some reason, have sailed some out of port. Sure, they lose the benefit of having the ships there, but then some US players do so at times to reduce risk.

[Courtenay]

Against competent US play (a maximally stacked Hawaii), the odds are greatly against it succeeding.

However, I played one game where the US player (one of my allies) was not competent, did not have enough forces in Hawaii, and lost Pearl. Wasp was captured. The Japanese player gloated about that for a very long time.