Could the Japanese have captured Hawaii if they had won the battle of Midway?

A Japanese victory at Midway would certainly changed the manner in which WWII was waged by the US/Allied forces and beyond a doubt it would have lengthened the war but would not have changed the eventual outcome.

Consider that by June 1942, Oahu, was garrisoned by 100,000–150,000 soldiers. At the time of the Pearl Harbor attack the Japanese had estimated that they would need to deploy at least 45,000 men in the invasion of the Hawaiian Islands.
#1, that would be an invasion force 10 times larger than they had ever landed amphibiously at one time and
#2 was a serious underestimation of the manpower required for a successful invasion.
At the time of Midway the Japanese never seriously considered an invasion of the Hawaiian Islands

Returning to the loss of Midway, with the Japanese in control of the Island the August 1942 counteroffensive at Guadalcanal could not have occurred and the Japanese invasion of Australia and New Guinea could not have been stopped. In fact the entire South Pacific would have been open to Japanese invasion. The Japanese could have easily occupied the New Hebrides, Fiji, Samoa, and Tonga thus cutting the main line of supply between the United States and Australia. With the US thus blocked the Japanese could have easily invaded northern Australia.

Beyond any doubt conditions in the Pacific would have seriously deteriorated with the loss of Midway but the Pacific war always comes back to the fact that by 1942 Japan's industrial capacity had peaked, whereas the American war machine was still growing. By mid-1943, the U.S. was launching an Essex-class carrier at the rate of one ship every two months. By August 1945, 17 Essex-class flattops would enter service, to say nothing of 9 Independence-class light carriers and dozens of small escort carriers. Simply put the war's outcome hinged on US industrial capacity.
So losing at Midway would not have changed the end of the war but would have seriously affected the prosecution of the war. The loss of Midway would have placed great pressure on the Roosevelt administration to change the Allied "Germany First" strategy in favor of reclaiming the Pacific losses to protect Australia.

The U.S./Allied forces had to maintain the supply line to Australia, so, if the Japanese followed a triumph at Midway by seizing islands straddling that route, the Americans would have had to shift the Pacific war effort to liberating those islands first, which would have demanding the reallocation of troop transport and landing vessels from the European Theater to the Pacific making D-day impossible.
In fact in July 1942 Secretary of War Henry L. Stimson and the Joint Chiefs of Staff, frustrated by British resistance to undertaking an early cross-Channel attack, recommended a shift to the defensive in Europe and adoption of a Pacific First strategy. FDR vetoed this approach due mainly to the American victory at Midway, which seemed to indicate that the existing Allied forces in the Pacific could successfully take on Japan whereas a defeat at Midway would have argued the opposite requiring a reallocation of forces.

Abandonment of the "Germany First" strategy could have had no other effect but to prolong the war in Europe by many months, perhaps allowing the Soviet Union to gain control of Western Europe. Certainly hostilities would have ground on long enough for the Manhattan Project to complete the first atomic bombs, which the U.S. then would have dropped not on Japan but on targets in Germany. Victory at Midway would not have won Japan the war, but could well have given the Second World War a very different turn.

(double post)

pinsog said:

I think the only thing an attempted Japanese invasion of Hawaii in 1942 would do is substantially shorten the war

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Quite possible, the operation would certainly be exceedingly fraught, but I don't think there is any guarantee of failure.

Looking a little more at the map for the invasion scenario, it seems like Wake Island is a pretty decent staging area for Midway. It had a good harbor and an airfield with room to park aircraft, and a decent capacity for storing troops and supplies, plus a decent harbor. It could in turn be supplied from the Northern Marianas or the Marshalls.

Johnston Atoll is another point from which attacks can be launched toward Hawaii. It had an airfield and was used as a base by the US. 940 miles to Hawaii as the G4M flies. So you could put long range bombers there for sure.

If you look at the second island in the background of this photo it looks like there is capacity for billeting and plenty of space to park airplanes. You can also see port facilities.

Might not want to go there today to evaluate it for IJN invasion of Hawaii purposes as they accidentally blew up a couple of nuclear missiles there in the 60's so there is plutonium scattered around the island. They also did Bio weapon and chemical weapons tests there and stored VX an Sarin and Agent Orange there too, all of which apparently left contamination, so probably strike it off the vacation itinerary altogether.

However in 1942 it's still clean of anything other than seagull poop so I figure you might be able to stage 100 or maybe even 200 more long range medium bombers for your raid on Hawaii, and probably better ones than you would use from Midway since it's closer. So add say another 150 G4Ms to the mix.

Schweik said:

Quite possible, the operation would certainly be exceedingly fraught, but I don't think there is any guarantee of failure.

Looking a little more at the map for the invasion scenario, it seems like Wake Island is a pretty decent staging area for Midway. It had a good harbor and an airfield with room to park aircraft, and a decent capacity for storing troops and supplies, plus a decent harbor. It could in turn be supplied from the Northern Marianas or the Marshalls.

Johnston Atoll is another point from which attacks can be launched toward Hawaii. It had an airfield and was used as a base by the US. 940 miles to Hawaii as the G4M flies. So you could put long range bombers there for sure.

If you look at the second island in the background of this photo it looks like there is capacity for billeting and plenty of space to park airplanes. You can also see port facilities.

Might not want to go there today to evaluate it for IJN invasion of Hawaii purposes as they accidentally blew up a couple of nuclear missiles there in the 60's so there is plutonium scattered around the island. They also did Bio weapon and chemical weapons tests there and stored VX an Sarin and Agent Orange there too, all of which apparently left contamination, so probably strike it off the vacation itinerary altogether.

However in 1942 it's still clean of anything other than seagull poop so I figure you might be able to stage 100 or maybe even 200 more long range medium bombers for your raid on Hawaii, and probably better ones than you would use from Midway since it's closer. So add say another 150 G4Ms to the mix.

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But the US would be keeping an eye on that field and as soon as the Japanese occupied it, it would become another target for B17's. Again, I would send them late in the day so they arrive at night, do a relatively low level pass in the dark dropping a lot of smaller bombs aimed at destroying aircraft. (That's what Saburo Sakai said we did in the South Pacific. B17's, B25's and B26's would do low level night raids). I would have PT boats and/or submarines using radar as pickets. If the Japanese launched a raid, it would be unescorted and facing probably 300-500 Army and Navy fighters alerted and in the air. Unescorted Japanese bombers didn't do well against US fighters. I'd have P38's up high, Wildcats below them, then P40's then P39's at the bottom. I think it would be slightly more dangerous than shooting a target sleeve but not much.

I agree with the problems a loss at Midway would have caused such as diverting material from the war in Europe, loss of islands and possible invasion of Australia.

Agreed the ending of the war with Japan wouldn't have changed had we not sunk a single Japanese carrier until August 6, 1945 when a lone B29 with a heavy escort of Mustangs and P47N's flies over the Japanese fleet and drops an atomic bomb over a dozen Japanese carriers either at sea or at anchor, followed up by a huge US Navy strike against the remnants of a horribly crippled fleet.

It doesn't matter what Island or Atoll the Japanese can fit 150-200 bombers on within range of Hawaii, What matters is supplying this force of bombers and being able to transport enough men and supplies to even approach a successful invasion. To land even 150,000 men (out number the defenders only 1 1/2 to 1) would require an invasion fleet close to the size of the one used for the Sicilian invasion. Except such a fleet would have to cover much more distance, even in stages.

The Japanese were chronically short of transport.
The Japanese were critically short of fuel oil for the entire war. ANY scheme that delays the invasion of the DEI just makes the fuel shortage worse.
Nobodies carriers were good for more than a few days of combat before the magazines to arm the planes are empty, along the aviation fuel tanks.
Japanese subs vs merchantmen was a near failure, US subs vs merchantmen went much better once the US subs got good torpedoes. Not soon enough for these scenarios but the Japanese logistics train was more vulnerable than the US logistics, Japanese were not as good at anti sub warfare.

Even if the Americans lost a Midway they still had cracked the Japanese code and could send raids to hit any of the hypothetical Japanese forward bases. Japanese also tended to use human labor to build bases vs bulldozers ( a bit of an exaggeration but the Americans turned into masters at quickly building air bases and infrastructure in short periods of time. Marston mat was in use by the summer of 1942.

Well, they had the sealift capacity to invade the Philippines with 150,000 men. And the 1.5 to 1 ratio would be helped a lot by a series of heavy naval bombardments, and if they could manage it, air strikes.

I could see the various atolls and islands previously mentioned being staging areas, though admittedly they are not close.

I agree with pinsong though the invasion troops spending 2 or 3 days steaming toward the target would be pretty rough. However Japanese troops did endure some pretty long 'commutes' a few times sometimes stuffed in very uncomfortable barges for days on end.

As for codes, didn't the Japanese occasionally manage to decipher some Allied transmissions too? I seem to remember something about that.

Shortround6 said:

The Japanese could certainly attack Hawaii if Midway had gone the other way.
Having even a successful attack is another story let alone an invasion.

I believe there are other threads on this.

It seems some people are making assumptions as to Hawaii's defences that may not stand up to scrutiny. Hawaii's defences did not depend entirely on the Navy or even the Navy and AAC combined. Hawaii is a lousy place to try to do an amphibious landing on.
The suitable beaches are few and well known (invasion scenarios had been war-gamed many times by local forces from the 1920s on.) There had been a frenzy of fortification construction from the date of Pearl Harbor. Ground forces had been much increased (and Hawaii was a staging area for the upcoming Allied offences, The US did not win at Midway and then decide to attack Guadalcanal and send everything for the Guadalcanal operation from the west coast.

Within weeks of Pearl Harbor two convoys of troops and equipment had left west coast ports with their arrival in Hawaii army ground forces were over 58,000 men.

"the unit reinforcements included two regiments of infantry, one regiment each of field artillery and coast artillery, and light tank, signal, and railway artillery battalions"

Further reinforcements were sent later and the outer Hawaiian Islands got garrisons and light support weapons.

However " With small additions during March, the authorized strength of the department became at the beginning of April 106,000 ground and 16,000 air troops, including replacements for all soldiers of Japanese descent; and the department reached these strengths before the end of June 1942. The Army air units to be retained in the islands for local defense were to contain 96 heavy and 24 medium and light bombers and 225 pursuit planes, and the Navy was obligated to keep 67 patrol planes on hand for long-range and local reconnaissance. "

Number of Army planes fluctuated and sometimes did not reach the totals in the passage quoted. Just before Midway there were 56 B-17s in Hawaii and 12 of them were sent to Midway on May 30th, however by June 10th 60 more B-17s had reached Hawaii. With the Midway victory some of them were sent on to other places in the south Pacific.

The American troops may have been green and perhaps not well trained but it is the Japanese who are trying to attack prepare positions over narrow beaches and into very challenging terrain.

View attachment 557689
There are often not a lot of flanking options for an attacker. Oahu is small 44 miles long and 30 miles wide. Modern map.
View attachment 557690
Like I said earlier. Beaches suitable for landing were well known and pre zeroed by defensive guns, avenues of attack once on the beaches were also well known and limited.
the two modern highways up through the center of the Island are only possible by tunnels through the ridge.



The Philippines were large, many places had to be defended and while the terrain could be rugged the distances allowed flanking maneuvers.

resupply for the Japanese would take weeks if not well over a month for a round trip by a ship.

Despite allied fears the Japanese had about reached the end of their logistical rope with areas they had already taken. They had neither the transport capacity nor the fuel oil to support far flung invasion schemes.

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All quite interesting, but a few counterpoints:

1) Allied dispositions on Hawaii may very well have been known to the Japanese and shore guns could be targeted.
2) Heavy naval bombardment could make a pretty big difference. Corregidor had big shore guns too.
3) The relatively small size of the island of Oahu could contribute to the rapidity with which the IJA and IJN marines could come to grips with American troops and possibly capture some of the main airfields and port facilities.

Contrary to comments upthread, I wouldn't envision sending G3M and G4M bombers by themselves to attack Hawaiian defenses. The attack would have to be coordinated with carrier strikes. If that was timed perfectly and nothing went wrong, it could make for some devastating attacks. I'm not sure B-17s could take out their staging areas either.

Sealift seems to be something they could sort out, if they did it in the Philippines as I keep saying and other places like Malaysia - they could even put troops and supplies on DDs as we know. However I agree fuel could be problem.

Another problem is that Japanese troops didn't do so well against Marines in Guadalcanal or against the Aussies in New Guinea, especially when the latter had good air support.

I think the scenario would actually hinge on what the US carriers did. If they were held back and not used, the Japanese could pull it off (perhaps). If they made a daring attack at the right moment, and didn't step on their proverbial junk, they could wreck the Japanese attack by sinking a few capital ships at the right moment and / or shooting down a bunch of the carrier planes. Timing could be enhanced by Code Breakers / intel intercepts.


All in all I think it would make a great board game or maybe a computer game scenario.

Schweik said:

Well, they had the sealift capacity to invade the Philippines with 150,000 men. And the 1.5 to 1 ratio would be helped a lot by a series of heavy naval bombardments, and if they could manage it, air strikes.

I could see the various atolls and islands previously mentioned being staging areas, though admittedly they are not close.

I agree with pinsong though the invasion troops spending 2 or 3 days steaming toward the target would be pretty rough. However Japanese troops did endure some pretty long 'commutes' a few times sometimes stuffed in very uncomfortable barges for days on end.

As for codes, didn't the Japanese occasionally manage to decipher some Allied transmissions too? I seem to remember something about that.

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The Phillipines were right across the street. 150-200 miles is different than 4,000 miles from Japan to Hawaii. Germany could invade Poland but Moscow stretches their supply lines. And again, 100, 150, 200 Betty bombers attacking Hawaii with 0 fighter escort when Hawaii had 225 Army fighter's and could have had another 225 fighters with only 2 trips with only Saratoga, that doesn't include Wasp and Ranger if they wanted to use them.

As a war game I agree it would be fun.

In a practical sense it would be a massive resource draw for the Japanese that was very unlikely to produce results.

The offensive air strikes have to produce significant damage. In the face of a significant defense that knows they are coming. In addition to radar, if they coordinate with the carrier the a they have set a reservation that the US can also read. That would be fun. Not only are the fighters up and the AA loaded but all the targets are ready.

Meanwhile B-17 attacks really just need to keep them awake and worried. Actual damage is basically gravy. Even inaccurate bombing is creating havoc that needs to be addressed and reducing morale, morale that continues to erode as the loses from attacks mount. Throw in some shelling from submarines at the smaller atolls for good measure.

Speaking of submarines, even with lousy torpedoes they are going to be gunning for the invasion fleet. They don't need to get many tankers to end the whole thing and they will know it.

Likewise air attack from Oahu or surviving carriers would be wise to look for the supply chain. If the carriers can circle around and hit the support ships it's game over....

pinsog said:

The Phillipines were right across the street. 150-200 miles is different than 4,000 miles from Japan to Hawaii. Germany could invade Poland but Moscow stretches their supply lines. And again, 100, 150, 200 Betty bombers attacking Hawaii with 0 fighter escort when Hawaii had 225 Army fighter's and could have had another 225 fighters with only 2 trips with only Saratoga, that doesn't include Wasp and Ranger if they wanted to use them.

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Very true, great point! However it's not what I was saying. The scenario I outlined was as follows:

• 270 Zeros from 4 fleet carriers and 4 light carriers and 130 carrier based bombers.
• 150 float plane zeros (A6M2-N) based at French Frigate Shoals
• 50 land based bombers (G3M "Nell" probably, for their range) at Midway
• And another 150 G4Ms at Johnston Atoll.

So that is about 420 fighters all together. Call it 400 to allow for a bit of attrition just getting into position. Plus another 130 carrier based light bombers and dive bombers, and the 200 or so medium bombers from Midway and Johnston Atoll..

I'm really not sure if the Japanese could have mustered a few more carriers, I tried looking through the list of them but it was a bit tedious to figure out. They had a bunch more escort carriers but those were quite slow. However they might be a good way to keep a reserve of another 200 or so fighters handy at your main three staging areas.

On the American side, keep in mind I don't think they had that many P-38s available in 1942. The 49th Fighter Group in the Solomons was never able to equip more than one squadron of them until almost 1944. Maybe at most you get 30 or 40 scrambled to Hawaii in time. The rest of your fighters are P-40s, P-39s and F4Fs, maybe some F2As and P-36s.

Tkdog said:

As a war game I agree it would be fun.

In a practical sense it would be a massive resource draw for the Japanese that was very unlikely to produce results.

The offensive air strikes have to produce significant damage. In the face of a significant defense that knows they are coming. In addition to radar, if they coordinate with the carrier the a they have set a reservation that the US can also read. That would be fun. Not only are the fighters up and the AA loaded but all the targets are ready.

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True but what if the Yamato, the Musashi, the Kongo, the Kirishima, the Fuso, the Hei, and the Haruna, along with a dozen or so heavy cruisers, had spent the previous night lighting up the sky with freight train sized tracers, showering shells on to the peaceful island and blasting the hell out of all the American airfields, port facilities, road junctions, bridges, and troop revetments with guns ranging from huge to ridiculous in size and power. Leaving massive, smoking craters where once delicate lae trees had stood...

Meanwhile B-17 attacks really just need to keep them awake and worried. Actual damage is basically gravy. Even inaccurate bombing is creating havoc that needs to be addressed and reducing morale, morale that continues to erode as the loses from attacks mount. Throw in some shelling from submarines at the smaller atolls for good measure.
Speaking of submarines, even with lousy torpedoes they are going to be gunning for the invasion fleet. They don't need to get many tankers to end the whole thing and they will know it.

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Don't forget the Japanese fleet is intact and have plenty of destroyers and sub chasers to keep after the American subs.

Likewise air attack from Oahu or surviving carriers would be wise to look for the supply chain. If the carriers can circle around and hit the support ships it's game over....

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I think this, this is what would save the day for the Americans. If their luck held...

Actually instead of sending say 7 battleships in at once, maybe 2 fast ones at a time with 3 or 4 cruisers come in at night, boom boom boom, then slip away beyond the range of the SBDs and TBFs before dawn. Keep this up for 5 days before the attack, and then send in 5 of them on the last night, keeping 2 in reserve as overkill in case of any attempted surface engagement of your transports.

The coordianted attack with carrier and land based bombers is actually what they did at the Philippines, several places in the Pacific rim and also on a much smaller scale at Darwin a couple of times. They knew how to do that.

We seem to be confusing things?
Invasion at the time of Pearl Harbor or invasion after the Battle of Midway goes to the Japanese?

By Mid summer of 1942 there weren't a lot of Japanese left on Hawaii to do any spying and the ones that were left were rather closely watched.

This scenario also assumes that the American fleet does nothing, even without the carriers. That is it assumes that the Japanese can do away with whatever ships are left in Pearl Harbor despite land based air and improved land based AA defenses.

Gettins several divisions from Formosa to North Luzon is hardly the same thing as transporting them from whatever the last refueling point was to Oahu, Please look at map, Oahu only has one harbor, trying to seize the port facilities is the whole point of the invasion, there are no secondary port facilities to seize.
The Philippine landings were pretty much unopposed.

from Wiki "Early on the morning of 12 December, the Japanese landed 2,500 men of the 16th Division at Legazpi on southern Luzon, 150 miles (240 km) from the nearest American and Philippine forces."

In Oahu the landing craft are going to be under fire for hundreds if not thousands of yards before they hit the beach.

Night shelling without spotters seems to be a good way to waste ammo. On the other hand, the spotters on shore can see the muzzle flashes of the bombarding ships and direct the shore batteries accordingly.

Anti sub work requires more than just a destroyer ( you need anti sub weapons) and sub chasers in the 1942 Japanese navy are pretty rare. They are going to be especially rare thousands of miles from the Japanese homelands/waters as they would need multiple refuelings (more than the destroyers) to make the voyage.

Shortround6 said:

We seem to be confusing things?
Invasion at the time of Pearl Harbor or invasion after the Battle of Midway goes to the Japanese?

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Invasion after Midway is won by the Japanese.

By Mid summer of 1942 there weren't a lot of Japanese left on Hawaii to do any spying and the ones that were left were rather closely watched.

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Sure but by then they already knew where the likely gun emplacements would be covering the approaches to as you put it, the very few beaches. Though there are plenty of beaches on Oahu to be honest.

This scenario also assumes that the American fleet does nothing, even without the carriers. That is it assumes that the Japanese can do away with whatever ships are left in Pearl Harbor despite land based air and improved land based AA defenses.

Gettins several divisions from Formosa to North Luzon is hardly the same thing as transporting them from whatever the last refueling point was to Oahu, Please look at map, Oahu only has one harbor, trying to seize the port facilities is the whole point of the invasion, there are no secondary port facilities to seize.
The Philippine landings were pretty much unopposed.

from Wiki "Early on the morning of 12 December, the Japanese landed 2,500 men of the 16th Division at Legazpi on southern Luzon, 150 miles (240 km) from the nearest American and Philippine forces."

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I'm not really sure what your point is. The Japanese landed 150,000 troops and 90 tanks on the Philippines eventually. How many did they land on Malaysia? Indonesia?

Also keep in mind the impressive and overwhelming attack on the Philippines was not very long after the impressive and overwhelming attack on Pearl Harbor. They were taking care of a lot of business all at once, and it worked.

In Oahu the landing craft are going to be under fire for hundreds if not thousands of yards before they hit the beach. Only if there are guns left to shoot them. There are also beaches on the west and east side of Oahu that landing craft could land on.

Night shelling without spotters seems to be a good way to waste ammo. On the other hand, the spotters on shore can see the muzzle flashes of the bombarding ships and direct the shore batteries accordingly.

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That is what star shells are for. They managed to wreck Henderson field a few times.

Anti sub work requires more than just a destroyer ( you need anti sub weapons) and sub chasers in the 1942 Japanese navy are pretty rare. They are going to be especially rare thousands of miles from the Japanese homelands/waters as they would need multiple refuelings (more than the destroyers) to make the voyage.

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Sub chasers may be rare but destroyers were not in the Japanese navy. If they were making a full fledged push to take Hawaii they would bring a lot of what they had, obviously.[/quote]

You seem to be denying any possibility of a counter to your scenario. For one that hasn't been mentioned - weather. They would have to launch this amazing endeavor weeks before their d day. Once they have begun their journey (that the enemy knows all about) they are committed to a very small window to attack. Linger someplace for the weather or surf to be more favorable and you're out of fuel oil and aviation fuel. The whole fleet becomes more vulnerable each day of delay. At some point you have to go home. Do the troop ships have enough food?

Send those battleships in to shell and those that survive the subs, counter fire from shore and sea, torpedo boats and mines (they knew you were coming) have reduced their supply of shells accordingly. They are now more vulnerable in a surface battle.

I have dove around Oahu when u was stationed there. The currents off shore are serious as can be the surf. Terrain ashore is tricky. There aren't that many beaches.

I think the most telling part of your post is your assessment of the Dec 7th attack. It the work of dilettantes, seriously. They were functioning at a strategic level. They went for the battleships, scrub tier move. They should have thought logistically and either had the sense to not attack or at least focused on the fuel reserves and the port facilities themselves. The very fact that those are harder to destroy in total should have been the warning they needed to not attack.

All of which underlined the issue with them trying to invade Oahu. Logistics. They can't possibly pull the logistical train together to sustain an attack. They have to burn fuel oil to make drinking water. The defenders have to turn a tap. The defenders just have to slow them down by not many days and the whole thing crumbles. There is no "living off the land" at sea. Things break daily and they have to be fixed.

Someone here can probably dig up the lifetime of a Zero's engine. Couldn't have been all that many flights.

Schweik said:

Invasion after Midway is won by the Japanese.

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Which would out this supposed invasion into July, August or Sept, depending on how long it takes the Japanese to improve whatever Islands/atolls you pick for forward bases , even assuming they got Midway at the beginning of June,

Sure but by then they already knew where the likely gun emplacements would be covering the approaches to as you put it, the very few beaches. Though there are plenty of beaches on Oahu to be honest.

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Knowing where the gun emplacements are on a map is just fine, knowing where your own ship is in the dark a number of miles off the coast without radar ( to within a few hundred yards) is the problem. Local currants and local winds can affect both navigation and gunnery respectively. Not to mention being shot at by shore batteries of which henderson field was in short supply.

As to the beaches, several beaches only a few hundred yds wide and only a few hundred yds apart are going to count as one beach for invasion purposes and many Hawaiian beaches are not suitable for invasion despite how inviting the sand looks,

Aside from headlands guarding the beach please notice the coral reefs blocking all but the smallest boats from getting to the beach.

I'm not really sure what your point is. The Japanese landed 150,000 troops and 90 tanks on the Philippines eventually. How many did they land on Malaysia? Indonesia?

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reread your own sentence. See the word "eventually", there is no "eventually" in attacking Hawaii, there is no area to gather up your forces once ashore, there is no safe place to shelter while waiting on resupply. You don't need to put all troops ashore in just one or two days but you don't have weeks either. The other point is you are using hundreds of not thousands of tons of fuel oil per day to get your invasion fleet to the invasion site, even if you pre position the fuel in your island bases or have extra tankers you need many times the oil to reach Hawaii than it took to reach the Philippines.

Also keep in mind the impressive and overwhelming attack on the Philippines was not very long after the impressive and overwhelming attack on Pearl Harbor. They were taking care of a lot of business all at once, and it worked.

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It worked but it took months to capture the Philippines, in part because they had to siphon of troops to attack other targets while they were on a roll. However the roll was over, The DEI was not producing the amount of oil the Japanese wanted. Tankers sailing with the Hawaii invasion fleet are not bringing fuel from the DEI to Japan. There was not going to be a 2nd surprise attack or invasion.

That is what star shells are for. They managed to wreck Henderson field a few times.

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Uh,,,,, no. Star shells only work if the firing ship has a visual on the target. or at least a reference point. Can the Japanese bombardment ships actually see the airfields on Oahu form 5-10 miles offshore? (that is assuming the 16in guns are knocked out, otherwise the distance might be much greater) the 16 in guns were in the open during the attack on Pearl harbor, at some point in 1942 they got concrete roofs that were 8 to 15 feet thick.

one of the 16 in gun positions after it got the concrete roof. Before or after your proposed invasion?

Sub chasers may be rare but destroyers were not in the Japanese navy. If they were making a full fledged push to take Hawaii they would bring a lot of what they had, obviously.

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and what they had were a bunch of destroyers optimized for surface attack. Great torpedoes but most interwar japanese destroyers only cared 12-18 depth charges in the first year or so of the war. Many had X gun removed to allow for more AA guns and up to 36 depth charges, later in the war even more depth charges were added, I am not sure if they started to sacrifice torpedo armament to do it.
But in 1942 their depth charge patterns were small and not very effective. The British started the war with a 4 charge pattern (which required two side throwers) then they went to a 7 charge pattern and then 10 and finished the war with a 14 charge pattern that required at least six throwers,
Better have a resupply ship or two with the invasion forces carrying lots of spare depth charges. Late war Japanese destroyers carried over 60 depth charges. do not confuse late war anti sub capability with 1942 anti sub capability.

I was actually in Hawaii for the first time ever just a couple of months ago. The beaches are few and all the ones I saw were very steep. The US had 12 inch mortars inside the extinct volcano just a couple of miles outside of the mouth of Pearl Harbor with multi level spotter bunkers dug into the volcanic rock. They had a great killing field in front of them along with 12 inch naval guns halfway between the mouth of Pearl Harbor and the extinct volcano.

150 float plane Zeros would be a great way of losing 150 well trained fighter pilots. I would say the Rufe was the best float plane fighter of the war but it was still a float plane fighter and tackling a P40 or Wildcat or P38 in a Rufe would not be my idea of a good time.

I still think that since Hawaii already had 225 Army fighters, and Saratoga was leaving Pearl the day after the Midway Battle with 47 Wildcats on board, I imagine they left a few behind for training etc. That means at least 275 fighters the day after Midway was over. If the US had lost, Saratoga could have immediately sailed to the US, loaded up 100 or more fighters and been back in less than 2 weeks. They could have flown off those fighters from several hundred miles out instead of going all the way to Pearl cutting down on travel time.

That's at least 375 fighters of only Saratoga was available.

How quickly after Midway would the Japanese be able to launch this attack?

I think alot of how feasible an invasion of Hawaii is( mindful that in my mind at least were talking feasibility of maybe between 1 and 2 on a 1 to 10 scale) just depends on how things go or which way the winds of luck blow so to speak.
If the US losses 4 carriers and a couple cruisers say at Midway and the remainder of the US fleet gets drawn into a or several surface engagements in which obviously the Japanese would have air superiority at sea at this point and the U.S. really gets gets the short end of the luck stick here as well( not that unlikely without thier carriers)
now how does the US resupply Hawaii?
Is Hawaii even self sufficient as far as food? I don't know.

A lot of variables.
There were plans to make Hawaii more self sufficient in food and tractors and seeds were sent to the Islands but it was decided that the existing crops of sugar and pineapples were more important to to the total war effort (After Midway?).
But the Japanese do not have the luxury of hanging around and "blockading" Hawaii. They have a very short window of opportunity before they have to head for home and or start towing ships that are out of fuel.
If the US fleet stays within a few hundred miles of Oahu ( depending on how many fields can be built on the other Islands in the weeks or couple of months between Midway and the invasion fleet showing up) it can be covered by land based air (at least to some extent) negating the Japanese carrier advantage.

The Japanese, even if they get ashore, cannot destroy in detail the defenders like they did in the Philippines or Malya. On an Island only 40 miles long there is not going to be much opportunity to outflank and isolate the defenders. And unlike Malaya some of the officers have been stationed there for years going over the terrain in war games. A real home field advantage.