The USN simply would have withdrawn to the west coast.  This action on the part of the IJN would have been unsustainable.  They would have withered on the vine although the war would have gone on a little longer, I say only a little as the Soviets would have been encouraged to enter the war earlier.

i don't think they had the logistical capacity to invade hawaii on a permanent basis but had they landed on pearl for say 2 weeks and done a thorough job of trashing the navy base it would have been a pretty heavy blow to the usn campaign in the pacific. 

i don't see the russians getting into the war any sooner as their primary goal was to crush hitler.  nicking some turf from the japs was well down their list of things to worry about.

US Army in Hawaii had three divisions based upon 2 regiments each. About 17,000 men. The Marines had 2000 men. The US forces were clueless, without any air support, had no naval support, and were cut off perminately from the  mainland at the same time the Philipines were. The Japs could cut use battlewagons to masticate the barracks on openning morning and probably land without any resistance.

 

The Japanese wanted an decisive battle early in the war and this would have prevented Guadalcanal and Coral Sea.

 

Check Six

 

Rocky

Secondly, I do not think they could have pulled off shelling the fleet.  Launching from carriers 200 miles out is one thing.  Getting surface ships close enough to put significant shelling on a target is entirely different.  Add to that the fact that unless they massed ALL of their battleships there was no way they could have effectively surpressed, let alone neutralize 19,000 men.  The U.S. today barely has that kind of firepower capability, in WWII no one did.  Not to mention all the sailors at Pearl you must include.  

An invasion was untenable.  I don't think they could have taken the island.  Even if they were able to capture the island holding it would have been even more impossible.  Unless they could hold and secure the port very quickly the fleet was at its endurance limit.  Once the troops had landed they had to either produce spectacular results immediately or face abandonment as the fleet withdrew to refuel and rearm.  That gives the Japanese, provided they could land all 15,000 men, less than 1 to 1 parity with U.S. Army and Marine troops.  Add in militia, navy personnel, any aircraft/ships that survived, a hostile populace and unfamiliar terrain and you get 15,000 killed or captured Japanese Marines very quickly.  

given the range from the beach to schofield barracks for instance the japs would have pretty much had to be right on the beaches to be shelling that barracks. 

for the japs to have landed a big enough force to take and occupy Pearl would have been a significant diversion of resources.  if even a quarter of the army guys were actually combat troops instead of remfs of various flavours the japs were in for a heck of a fight and the brigade of stuarts would have been impossible for the japs to deal with at the time.  throw in the forts and damaged battleships fire support and it would seem even taking Pearl was an impossible dream pretty much.

Now you suggest that they take Oahu?

 

no herald i suggested a spoiling raid on the base at pearl.  i had in mind a couple brigades for a week or two while their engineers trashed the repair facilities and anything else that seemed useful and hard/time consuming to replace/repair.

 

the japs would have had to pull some pretty deft commando raids on those forts and then some deft impromptu work on the damaged battleships to take them out of the picture to let the japs bring their gun boats in close enough to support the raiders.  just too many things would have to go right for the japs to be worth trying no matter how tempting the prize was.

The problem with that limited objective Ehran is that it raises the question of why even bother with the ground troops at all?  The Japanese cant take the island, that is a given.  The Japanese can't even capture pearl with the density of forces there an the forts.  If your objective is simply to hold the ground while the engineers go to work, why bother?  I sincerely doubt they could hold for two days let alone two weeks.  If all you want to do is raise more hell with the harbor you can do one of three things that do not involve ground troops:

1)  Send in another air raid as was originally planned (aborted in RL as the base was now on full alert and losses would have been much heavier.)

 

2)  Do some retargeting work in the initial air strikes

 

3)  If you have a hankering to use the surface ships sail your big guns closer to Pearl and let fly with them.

 

None of the alternatives above require ground troops which would have been the equivalent of pissing men away anyway.  However, if you are going to use the troops then the objective must make it worthwhile to do so. 

Suicide by the numbers wasn't the Japanese tactical gameplan until after Spruance skinned them alive.

This is one of those few times where the plan that took place and the results it gained were ALMOST the best they could have been.  

it does seem more than a bit odd they didn't mine the channel into pearl given the payout for a relatively light investment.

Sorry it took me so long to reply on this thread but my schedule has been interesting the last couple of weeks and I wanted to give some time to any reply I made here. This thread is really my idea from Gog's giveaway. GOG I will forward my contact so I can get my Playboy magazine. I haven't looked at one in many years & it seems this will be an odd issue to say the least. First some background as I understand history:

 

Japan's objectives in WWII were best described as an attempt to seize resources, at the expense of their rightful owners, to allow for their economic expansion. They seemed at best to feel the US was another pushover like Russian had been at the end of the 19th century. The Japanese strategy in the Pacific included a "decisive fleet battle" which is literally a quote from the then Japanese war theory. This decisive action was designed to be a bloody nose to the US. It was to send a message to keep to their own affairs and allow Japan her rightful place as the leaders of the Pacific Rim. For some unfathomable reason the Nippon leadership thought the US would settle for that. This decisive battle was considered possible since the IJN was arguably bigger and somewhat more modern than the USN's Pacific fleet at that time and Japan didn't have naval interests in other hemispheres like the USN did. Further, all references I know of quote the Japanese military leadership as seriously under rating the fighting spirit of the US military in general and the US population in specific (it remains a curious repetition of history that the slugs, thugs, and despots of the world always assume that the US will shrink from a fight. How many would be Hitlers have we squashed so far? I digress.). The Japanese never intended to fight a long war of attrition against the US. Their strategy was to hit hard, hit early, and make it seem quite sensible for the US to accept an cease of hostilities that left them in charge of the Philippines, China, and South East Asia. All Asian countries that the Imperial Japanese Leadership thought rightfully belonged within their sphere of influence. Japan felt the time for the Europeans whom had spent so much of the preceding 150 years siphoning away these valuable Asian resources needed to come to an end so that the Japanese Empire could make the final jump to the modern world. Wrong headed thinking but there it was. If only they knew in 1941 all they had to do to get ahead was out import US on the world market and just buy the Pacific Rim they could have avoided a generation lost to war death and a couple of Atom bombs? Interesting question to contemplate.

 

The Pearl Harbor raid was not really thought of as the "decisive battle" it was really an attempt to tilt the game in Japan's favor from the earliest possible date. The real targets of the raid were supposed to be the USN aircraft carriers stationed there. Namely the USS Lexington and the USS Enterprise together with their air groups. The US owned 6 carriers on Dec. 7 (seven if you include the smaller Ranger which I don't think ever saw Pacific combat) and the Japanese owned a total of 10. To knock that number down to 4 v. 10 would greatly help the Japanese war effort. It would have been significant given the fact that Japan knew it couldn't out produce the US in a long fight. A short war helped the Japanese. Tilt the odds far enough that just maybe the US would take its ball and go home.

 

US forces infantry at Pearl Harbor included 3 divisions. The 24th and 25th which were regular U.S. Army and the 299th which was a local Hawaiian Guard Division. Each Division had 2 regiments with the local Hawaiians having the smallest of the group of regiments numbering only 950 men each at the opening bell. The 299th was dispersed greatly on the surrounding Islands with the 24th and 25th being based in Oahu. The 24th was supposed to be responsible for the North of Hawaii and the 25th was covering the South, Diamond Head and Pearl. A California National Guard unit was responsible for artillery. I don't know their exact number. The Marines had a total of about 2,000 troops in Hawaii of all sorts. Total military personnel including the Air Groups and Navy added up to around 43,000 men, women, dogs, cats, nurses, and  cooks and bottle washers. A big enough number by itself but mostly not ground pounders. The US force status was clearly not ready for combat. US logistics were concentrated in supply depots and secure bunkers and not dispersed into the field where they would be needed in the event of an invasion. US aircraft were not parked in their revetments (built in the summer of 1941 which would have protected the modern P40's from all but the most determined strafing attacks) but instead they were sitting on their respective tarmacs lined in perfect formation wingtip to wing tip. Peace time perfection rules applied. How many times has it been said that peace time leadership and wartime leadership have different goals? One concentrates on bean counting and formation drill and the other's objective is to survive while allowing the enemy to die for his country. Only recently had US army troops been allowed to draw a basic field kit of enough ammo to carry with you into the field in the event of a "drill". That probably only means about 100-200 rounds each, no field artillery was deployed and those ammo were counted and stacked in logistical centers too. Stuff that is stacked is easier to polish and count. Commanding General was Walter C. Short. He was retired within months of the attack.

 

The Japanese had every opportunity to make Hawaii/Pearl Harbor a significant victory. The 24th division didn't start moving from the Schofield Barracks (probably marching) towards their defensive positions on December 7 until 9:30 am. Nobody was in any position to repel an attack for about 12-18 hours after the bombs started to fall on that Sunday morning and then they lacked the ability to defend in depth probably for another good 24 hours. Hawaii on sunrise of December 7 was wide open.

 

 

The two fleet carriers the USN did have in the theater were performing other duties. The Lexington was Headed to Midway Island to deliver attack aircraft to that remote outpost and the Enterprise was only a couple of hundred miles away returning from having delivered aircraft to Wake Island. In fact Enterprise aircraft had been flown out to shore and got caught up in the attack on December 7. These ships were operating separately and without oilers. Would they have had fuel to make California? or Australia? in the event they were caught in the open.

 

Japan's failure to sink 7 of the 8 heavy cruisers the USN had present, most of the destroyers, and any of the Carriers was a Japanese failure of the greatest possible magnitude. They lost any possibility to win the war (under their own flawed strategy) on December 7 when they dropped into their attack runs. The ships they did succeed in damaging included some types that were arguably too old to compete against newer types. The psychological impact of the attack galvanized the US into total war that ended in the decimation of the Japanese Empire.

 

I suggest that an alternative strategy to make Hawaii a firmer point of contact would have been preferable to what the Japanese did. Even skipping the Pearl Harbor attack all together might have been a better alternative. The Japanese never again in the war had the odds that they had on that day on December 7. They never had two USN carriers working by themselves and totally uncoordinated up against 6 of their own top of the line carriers, they rarely again had complete air supremacy (they had the same over the Philippines and S.E. Asia on the same day), they rarely if ever again had such complete naval supremacy over a major surface battle space. The only time to ever have the "decisive naval action" was at Pearl. There were challenges to be sure to making a stand at Pearl but the options they chose were challenges that ultimately lead to their doom.

 

Tojo blew the pooch when he had Nagumo turn tail and run home. In doing so he lost the war on the opening shot.

 

Check Six

 

Rocky