What if...the Japanese had landed troops in Hawai'i immediately after bombing Pearl?

Read this one in a book too: what if, on the heels of their attack on Pearl Harbor, the Japanese had landed a sizeable landing force and methodically taken over the islands of Hawai'i? What would the U. S. response have been? Could the U.S. even have responded without access to the bases on Pearl?

 

good question!

 

Did they have the necessary shipping to accomplish that at such a distance?

 

How big is this sizable force?

 

SP, I'm not tracking on the shipping. I think, and I am going out on a limb here, that they could have, and probably would have, "lived off the land" until they could be resupplied with goods from Japan. And considering the number of Japanese-born islanders already living in Hawai'i, I don't think they would really have been hurting too bad.

 

Sloniksp, I have't been able to find anything that gives the disposition of gound forces on Hawai'i on 7 Dec 1941. Everything I have seen so far concentrates on the ships in port and out to sea. So, going strictly on an uneducated gues, I would say troops in the vicinity of 40,000 to 50,000. Enough to take over the bases, keep in mind that the vast majority of all servicemembers were on weekend liberty and not on base (and thus had no access to their issued weapons), and enough to quell any civilian uprisings.

 

Are you suggesting they invade the Hawaiian Islands instead of the Philippines and Malaysia? I doubt they had the capabilities to do both. Also, the Japanese weren't very good at coordinating large scale landings, they hardly ever landed more than 1 division at a time.

 

JagdtigerI, yes, I am suggesting that. Maybe not instead of, but first, and then PI and Malaysia. I think they would have had more to gain if they could have taken Hawai'i out of the picture first. They would not have had to watch their back door. No Hawai'i means no place in the Pacific for the U.S. Navy to re-fuel and re-fit their ships and that would have hampered the U.S. in the Pacific.

 

I can't really verbalize why but I feel like this idea wouldn't be possible for Japan. I am sure DA or TA will come explain why soon (or mabye brndirt)

 

Or maybe me!

Lets imagine, that the 40-50k Japanese soldiers cramped in their vessels managed to somehow land in Hawaii undetected. Then what? Even if they had captured Honolulu what then?

Japan has no capability to support such a force so far away. Japan's oil situation isnt even being mentioned here....

What would Japan do with the British and American troops now able to set up defenses or evacuations from the Philippines and Malaysia?

Why even land a force in Hawaii?

 

The USN would have still had Midway.

One thing i know for sure is that if the Japanese had taken pearl,they would have had alot of fuel oil,large amounts of Fuel oil was stored in tanks at pearl that were left un touched by the japanese.

They would also have the American sub base facility's,large amounts of fuel+a close base to the west coast could mean that the japanese sub corps could oporate well off the San diago naval port.

I think that if the japanese could have befor hand,and i stress "befor hand" amassed large amounts of food/ammunition and most of all boots (infintry) somplace near Hawaii,then i do not see why they could have just conducted the airaid,then had the fleet land Marines on pearl aswell as other strategic areas,followed by have the main ground force comein and secure and completely take control of the islands.

They would need to have the Fighter planes fly a round the clock "cap" around the mainland American aprouches,because i would think the American CNC would want to strike back at the japanese asoon as possible with longrange bombers.

In the long run the japanese would have had to plan this out for years befor they went and did it.

Now if the japanese had landed in Hawaii aswell as Alaska or maybe even south Western Canada simotaniously,then this would have been a very big problem for the Americans.

Befor the American warmachine could have done anything to help England,it would have to do everything in it's power to stabilize the situation on it's own front befor really doing anything against Germany.

But pulling this off would take so much Japanese man power that it would have made there campaigns in southeast asia alittle more not as smooth for lack of better words.

 

Well, since I'm mentioned, I guess I should at least give it a shot huh? This is a quite detailed analysis of the FOLLY of Japan trying to force an invasion of Hawaii. There is almost NOTHING to gain from such a venture except the MINOR inconvenience of denying an enemy a base of operations.

Goto:

The Hawaiian Invasion, and other Nonsense


And scroll down to "other really crazy", and read up on the limits of Japanese transports...

You might also "enjoy" reading If Mahan Ran The Great Pacific War; by John A. Adams. He discusses at length the problems of such an invasion for Japan, logistically, tactically, and strategically. There were appoximately 60,000 armed military personnel in Hawaii plus a civilian militia who would be drafted/volunteer to help fight. Let's not forget that the highly decorated 442nd was made up mainly of Hawaiian men who were removed from the island after the Pearl Harbor attack and sent to the mainland for "further" training. They fought the Germans, and had felt betrayed by Japan and wished they could have fought in Hawaii.

Using the accepted ratio of invader to defender, a three to one advantage is the normal so the Japanese would need about 200,000 men, and supplies, to invade with any hope of success, not 50,000.

The War Department (by September 1941), prescribed an impressive allotment of antiaircraft and artillery weapons for Hawaii: 84 mobile and 26 fixed 3-inch guns for level and high altitude firing, and provision for replacing some of them as soon as possible with even more modern weapons; 144 of the newer 37-mm. automatic weapons; and 516 of the .50 caliber antiaircraft machine guns for action against low-flying aircraft. This ignores the shore batteries which existed, mostly six and eight inch cannon.

By the time of Pearl, the Hawaiian department had four antiaircraft regiments, and it was scheduled to receive a fifth before the end of the year, it and its personnel were still on the mainland on Dec. 7th but were on the island by the end of December.

In the year preceding the Pearl Harbor attack, the Army's officer and enlisted strength in the Hawaiian Department (ignoring Navy and USMC numbers) grew from 28,798 to 43,177, and Hawaii remained the largest of the overseas garrisons. Only the Panama Zone held more American troops when the Japanese attack on Hawaii came, there were nearly 58,000 Army troops on guard in the Canal Zone, but they could have been transferred to Hawaii if needed to counter an invasion.

Now, since Hawaii gained the Japanese nothing but another far flung outpost, what would be the advantage? Let’s not ignore the real Japanese experience at Guadalcanal. This shows the limits of their logistics tail when it came to supporting troops any great distance away from their main bases. The Japanese called Guadalcanal "starvation island", and the commander there pleaded with his superiors not to send more troops, as he couldn't feed the ones who were already there!

The Japanese navy literally had no fleet oilers, troop transport ships, nor cargo transports for supplies, and was reduced to using destroyers as supply ships and troop transports, a terribly inefficient way to transport men and supplies. The guantlet to run to Hawaii would be no less dangerous.

 

Would have probably motivated the Americans to put recapture of Hawaii ahead of European Theater.

 

Clint is absolutely correct.

The Japanese didn't have enough shipping to pull off an invasion of Hawaii and the other operations in Malaya, Philippines, Borneo, and the NEI. and these landings were extremely critical to the "Strike South" strategy aimed at seizing the raw materials, notably petroleum, which was the rationale for going to war in the first place.

Oahu was probably the most heavily fortified island in the Pacific in 1941. It would have required at least three divisions to assault and take the island; the Japanese had neither the troops nor equipment needed for a successful landing. Nor did it have the logistical wherewithal to keep three divisions supplied over the oceanic distances involved. Then there are the issues of air and naval support which would be necessary to hold Oahu; where would that come from when Japan was engaged in operations in Asia and the Southwest Pacific?

One thing you should do before delving into alternative history books is study the historical record so that you can make some informed judgments as to the feasibility and likelihood of the author's departures from reality. The Hyperwar series is a good place to start.

HyperWar: World War II on the World Wide Web

 

How do they sneak an invasion force in? Transports are a lot slower so they have to either start a lot earlier than the CVs or the latter has to travel slower or they come inconsiderably behind the CVs. Any one of these makes the detection of the raid much more likely. Also consider what sort of support is coming with the transports. One reason the PH raid was successful is we had a good idea where the Japanese battle fleet was. If it dissapears a lot of alarm bells are going off and everybody is looking a lot harder. If it's not there then the invasion fleet has problems with shore batteries (not that it doesn't anyway) as well as surviving USN vessels. The CVs can't hang arround all that long either. If they do and launch repeated raids their available AC will shrink quite a bit after the first couple.

 

Yes, I agree with DA, lwd and brndirt1 would be a logistical nightmare just to transport the troops for an invasion. Plus the problem of keeping up with the carriers' speed. And keeping them supplied (assuming they had overpowered the American garrison in Hawaii and that would depend on the number of Japanese troops tasked to the invasion) would be next problem.
I had thought of proposing instead a raid instead of an outright invasion. But as I reviewed my own proposal, I disregarded it.

The Pearl Harbor attack worked for the Japanese worked because they kept things as simple as they could. Adding a land element would have made things more complicated for them.

 

There were a lot of USN warships at Pearl, that would be pressed into being semi-mobile heavy artillery batteries.

Look what happened to the German offensives at Anzio when they met with shipboard gunnery.

 

Keep in mind, not all destroyers, battleships, and others were knocked out. The Pacific fleet, while heavily damaged, could definately have wiped out even a protected landing force. And it was a base, so they would probably be well prepared for a naval attack.

 

You should just make it so that all new members have to take a quiz on the What If Forum Rules before they can join..save you some of the hassle