Monday, June 14, 2021

What if Japan's attempt at a decisive June 1942 'Midway' battle, had been at Ceylon instead?

Another amusing 'what if' that came out of the current series of 'what if' articles. Enjoy.

What if Japan had made a serious effort to finish off the USN first? Rather than shifting most of their attention back to Malaya, the East Indies, Darwin, and the Indian Ocean for 5 or 6 months, and allowing the USN so much time to recover?

And by that, I mean what if Japan had at least followed through with at least a third strike on Pearl Harbour, or, better, with an actual invasion of Hawaii. 

(See my previous post on the debate over Japanese plans for such an invasion of Hawaii. Yamamoto and Nimitz both stated categorically that not following through was the greatest mistake the Japanese ever made.)

What if the Japanese had pro-actively concentrated on a 'USN first' strategy, and left the 'clean up' against their other flank until they were completely sure the USN threat was properly undermined?

What if they had concentrated most of their resources from December 1941 until May 1942 on completing the destruction of the USN – rather than wandering backwards and forwards to raid Darwin and the Indian Ocean – before trying to force a Midway style conclusive battle? 

If they had substantially reduced the USN in that way, then the Midway style 'decisive battle' plan would have been aimed at the British Eastern Fleet at Ceylon instead.

The two front trap...

Trying to solve the two front trap was the defining issue for aggressors in both World War's. The Schlieffen Plan of WW1, and the Pearl Harbour/Indian Ocean raids of WWII: were both samples of how failing to solve this issue guaranteed losing the war.

Japan's problem was that they couldn't risk seizing British and Dutch possessions without dealing with their vulnerable flank against the US.

Equally, they couldn't risk dealing with the US without opening their vulnerable flank against potential British/Dutch counter operations. (It's not just the 'possible', 'eventual', threat of a British fleet strong enough to mount an actual offensive they had to fear. Don't underestimate the immediate threat of those dozens of Dutch submarines based in Java against vital Japanese communications in the South China Sea between their homeland and their forces in China and Indochina.)

However it is interesting to speculate on whether it would have been more sensible for the Japanese to concentrate their first few months on the Americans, just assuming the British would not be in any position to mount a major counter threat for many months? (A pretty realistic assumption in early 1942.)

Could that have been more effective than splitting Japanese forces between operations against everyone simultaneously?

In reality of course, we know that the impressive looking efforts careening all over 1/3 of the globe trying to take out the USN at one end and the RN at the other end: just meant that neither was really defeated badly enough to be driven from the field more than temporarily. Despite the Allies slower battleship units sometimes being pushed back as far as the African or US West Coasts, worryingly strong Allied mobile forces always remained hovered around the Indian Ocean and Central and South Pacific. Forces quite capable of mounting Doolittle raids; invasions of Madagascar; spoiling attacks on the Andaman's; or around New Guinea; or at Guadalcanal. 

But instead of concentrating on finishing off one opponent or the other, the IJN just rushed backwards and forwards to more and more frantic attempts to achieve 'decisive' results here or there, usually with ever decreasing numbers of planes operating from less and less carriers each time.

What could they have achieved by concentrating on one opponent at a time?

Properly taking out one ally at a time?

I think we have to accept that the IJN simply couldn't take its whole navy to deal with the RN in the Indian Ocean in December 1941with an undamaged USN 'at peace' on its flank.  Their logic in thinking they had to reduce the threat from the USN even just temporarily if they were going to attack the British Commonwealth, is pretty unassailable.

But should we write off the idea that they might have concentrated practically their whole navy on the USN for the first 4 or 5 months, before worrying about cleaning up Malaya and the Netherlands East Indies? Decisive victory on one front should automatically allow for a much better attempt at decisive victory on the other front. Particularly as the RN needed at least 5 or 6 months to gather a reasonable force for even defensive operations, let alone for offensive ones.

But in this scenario, it would be far easier to completely finish off the threat from the USN (at least for several years), while reversing the 'final battle' strategy for use against the RN instead!

With the USN reduced to impotence, and the main Japanese fleet based at Singapore (which it actually was sometimes, even under the two front threat), then the IJN had a real chance of enticing the British into a decisive 'Battle of Tsushima' in mid to late 1942. 

Consider a Midway style operation, but aimed at Ceylon, and with no effective USN to threaten its flank? If the Japanese had garrisoned Hawaii and Midway already, and done a couple of Darwin/Indian Ocean style raids on the US West Coast (hopefully reducing the USN to only one active carrier the way they actually did in late 1942 anyway): then such a Midway style operation might not even lack Shokaku and Zuikaku? (Admittedly the attrition rates of such a series of attacks would still see much reduced squadron numbers, and a lot of less skilled pilots, in the Japanese carriers. But it is still a sobering thought.)

Should the IJN have had its own 'Germany First' policy, on the same logic basis of knocking out the greatest threat, and dealing with the less  immediately capable foe later? 

Should Japan have gone full 'USN first'?

Most sensible strategists would probably say yes. If you are going to throw the dice in taking on too many enemies, then concentrating on a decisive blow against one of them before spreading your forces against several is pretty much Strategy 101.

But would it have made a difference?

In reality all the wandering back and forth for 6 months prevented the IJN from concentrating a strong enough strike to win at Midway. (Though there was still a lot of luck involved in the US victory.)

But frankly their situation might have been in no way improved had they spent those 3 or 4 months decisively defeating the USN, and given the RN the breather it needed to get a proper force in place in time to face whatever the much reduced IJN could throw at them after occupying Hawaii and bombing US West Coast bases.

In fact it might come down to whether they IJN could get the USN out of the way and re-concentrate against the RN by April 1 (when the Indian Ocean raid actually happened... probably the last time they had a really good chance), or if it still would have had to wait until at least May (Coral Sea), or June (Midway itself).

The delay until at least May, and very probably until June, might have been enough to change everything...

A June 1942 'decisive battle'... of Ceylon?

The actual Indian Ocean Raid in April 1942 saw 5 IJN carriers and the 4 Kongo class battlecruisers deployed; while the Kaga went home for service and repair, and the main IJN battle-fleet stayed defensively 'closer to home'. The Japanese faced a hastily gathered and still incomplete force of 3 British carriers – the modern armoured carriers Formidable and Indomitable, and the smaller, slower Hermes – and 5 battleships – the modernised Warspite, and 4 older and slower Revenge class.

But what if the IJN didn't arrive until the time of real Midway? What would they have faced then?

In this scenario lets assume the actual forces Japan used at Midway. 

7 Japanese carriers and 7 battleships, in 3 separate forces, against the ships Britain would have available by then, 5 carriers and 9 battleships.

For Japan, the carriers - Kaga, Akagi, Horyu and Siryu - plus the battlecruisers Haruna and Kirishima in the Striking Force; and the 3 battleships from Yamamoto's Main Body - Yamato, Nagato and Mutsu - plus their escort carrier Hosho. Plus the battlecruisers Kongo and Hiei and carrier Zuiho with the invasion force,  and a couple of seaplane carriers, up to a dozen cruisers and 30 odd destroyers split between the 3 forces. Operating perhaps 240 carrier aircraft.

[Another 4 slower Japanese battleships and 2 light carriers were feinting against the Aleutians, but even though Yamamoto's immediate response to the loss of 3 carriers was to call those two south at speed, there was no way that they would have got there in time to be of use. So we will discount that force, and assume that in a major Indian Ocean operation, those units at least would have stayed 'closer to home', defending Japan an its vital communications in the South China Sea.]

For Britain the armoured carriers Illustrious, Formidable and Indomitable, the older fleet carrier Eagle, and the light carrier Hermes (the equivalent of the Hosho). With about 160 carrier borne aircraft, plus a similar number in land based support on Ceylon, meaning perhaps 340+ aircraft.

[Roughly similar to US numbers at real Midway, but with 5 flight decks rather than 3 for the Japanese to have to find and sink... 3 of them the sort of armoured decks that easily shrugged off Japanese bombs and kamikaze strikes later in the war and continued operating! As one US observer noted in 1945, "A hit that would put an American carrier in dry-dock for six months, in the RN is just 'sweepers man your brooms'."]

Also 9 battleships: Nelson, Rodney, Warspite, Valiant, Malaya, Revenge, Resolution, Ramillies and Royal Sovereign. (Compared to NO US battleships available for the USN at Midway...) 

And as a bonus the RN would have considerably more cruisers, destroyers, and possibly even submarines than the USN had available for Midway. Midway 8 cruisers, 15 or so destroyers. Ceylon a bit harder to say, but back in March they had had 7 cruisers, 15 destroyers, and the numbers planned for redeployment should have at least doubled that by June. Only in submarines did the 19 the USN had at Midway probably outnumber the total the RN would have had at Ceylon. 7 were available in March, and the number would have more than doubled by June, but perhaps not tripled...

[Note - for the curious and for pedants – the deployment dates of RN capital ships are from British Cabinets Principal War Telegrams (B). 9. no 189; and (E). 1. no.334.]

In reality of course, at Midway the Japan didn't have their 7 carriers and 7 battleships close enough to support each other. The strike force of 4 carriers and 2 battlecruisers was defeated long before the Main Body or the Invasion Force could add their 5 extra battleships/battlecruisers and 2 light carriers to the mix. And way way before any call the other 2 light carriers and 4 battleships 'trailing their coats' in the Aleutians would have helped. (The IJN's fabulously overcomplicated plans, and constant dispersion of forces that would have done better concentrated repeatedly saved the Allied cause. Imagine if the IJN Strike Group had actually included all 9 available carriers supported by even just the 7 27+knot – of the 11 available – battleships! Game over.)

Frankly it would be a far more even fight between the RN and IJN at Ceylon, than the fight between the USN and IJN at Midway actually was. With the RN actually having superior numbers in both carriers and battleships (as well as aircraft) by the time of Midway, and able to slug it out in a way that the 3 US carriers with no battleship and very little cruiser support simply could not have risked. The USN could only 'ambush and run'. The RN would have been able to stand and fight, and perhaps even pursue.

Some qualifications on the dangers to the worldwide strategic situation

Just to note the effects of such a concentration of British ships, and the probable effects on other theatres...

Present in the Indian Ocean by April 1 were the carriers Formidable, Indomitable and Hermes, and battleships Warspite, Revenge Resolution, Royal Sovereign and Ramillies. This was already the biggest concentration of allied capital ships anywhere in the world at the time.

Reinforcements targeted for arrival during April and May were the carriers Illustrious and Eagle, and battleships Valiant, Malaya, Nelson and Rodney. The planned total of 5 carriers and 9 battleships in one fleet being by far the largest concentration of capital ships that any nation could field so far from home prior to the USN's 'luxury of new and rebuilt shipping' available much later in the war. 

[In fact, at that point, the only way any other navy on earth could field a bigger fleet in one place, was if Japan could take the risk of moving practically her entire navy 10,000km – that's a quarter of the globe – away from home waters... That's between 4 and 5 times the distance from home of even the furthest Japanese deployments for the Midway operation... Frankly taking that sort of risk is fantasy stuff, even if the entire USN has been practically eliminated as a threat. Imagine what fun the USN could have with some 'Doolittle raids' if they were absolutely certain that the nearest IJN battleship or carrier was 10,000k away!]

But, to be honest, I think that if the RN had had to concentrate this much in the Indian Ocean for most of 1942, then Malta would have fallen, and the North African campaign would have dragged on for even more years. So we can't pretend there would not be problems in the RN making such deployments. (And Churchill queried Roosevelt about adding the two US ships currently assisting the RN in the Atlantic - the brand new battleship Washington and the light carrier Ranger - to that total, which would have made the Mediterranean situation even worse... But King was, unsurprisingly, totally opposed.)

However too many people overlook the fact that Rommels last great surge forward in North Africa, that lead to the battles of Al-Alamein, were precisely because the RN did re-deploy most of these ships to the Indian Ocean when needed in early 1942. Effectively reducing their Eastern Mediterranean deployments to only a half dozen cruisers and a couple of dozen destroyers, thus allowing Rommel the supplies and freedom of action he had previously lacked. 

(Thus also keeping the interwar 'main fleet to Far East' promise to effectively abandon the Mediterranean if Australia or India were actually under threat. Too many people – particularly British and Australian 'historians' – fail to notice that minor detail...) 

Most of the RN ships named above were either already already deployed, or still on their way, when the USN's Coral Sea victory in May reduced the pressure. The Midway victory reduced pressure even further, and actually allowed more than half the Eastern Fleet deployments to turn back to the Mediterranean and spend the middle of 1942 saving Malta instead. (The vital Pedestal Convoy in August 1942 - escorted by 4 carriers, 2 battleships, 7 cruisers, 32 destroyers and 7 submarines – was only possible because the remaining Mediterranean carriers – Victorious an Argus – could be reinforced by elements withdrawn from the Eastern Fleet after Midway. Specifically the battleships Nelson and Rodney, and the carriers Indomitable and Eagle.) 

However there is no doubt that had the USN continued to suffer defeats at Coral Sea and Midway, the RN's increased deployments to the Indian Ocean would have had to go ahead. As it would have anyway  had Pearl Harbour been occupied, or had the remnants of the USN been pushed back to California bases. So saving the situation in Asia would have been at dreadful cost in the Mediterranean. The war in Europe might have been extended by another year or more.

Tactical Perspectives of a 'Battle of Ceylon' (on 4-7 June 1942, time of Midway battle)

1. Surprise

Much is made of the fact that intelligence intercepts meant that the USN knew the Japs were coming at Midway on June 4. Most people don't remember that the British Eastern Fleet also had intelligence intercepts for the April 4 Indian Ocean Raid. Admiral Somerville had positioned his fleet perfectly for a night ambush on the day intelligence expected them, April 1... (Only for the Japanese to be delayed by 3 days by oiling issues). If the IJN had turned up at Ceylon in June, you can bet the farm that the RN would have had adequate intelligence to mount another ambush.

But instead of Nagumo's 4 carriers and 2 battlecruisers facing only the 3 USN carriers and no battleships they faced at Midway; or facing the 3 RN carriers and 5 battleships they would have faced in April; by June the IJN would face 5 RN carriers and 9 battleships... the 4 RN carriers and 5 battleships of the Fast Force, with the other 4 battleships and their support carrier of the Slow Force perhaps 50/50 chances of being close enough to support. 

Given it's intelligence and radar superiority, the element of surprise - both strategic and tactical – would almost certainly go to the RN. 

[As it did in April, but unfortunately only after Somerville had spent 3 fruitless nights in ambush position for the expected April 1 arrival, and then returned to his secret base at Addu Atoll to refuel... Catalina recce planes spotted the Japanese fleet just as his slow force was entering harbour, which meant his fast force could sail again within a few hours to reposition for ambush, but the slow support force not until much later. See Wikipedia and Armoured Carrier. Nonetheless by the evening of the 5th Somerville was again in position to ambush, and as darkness approached on April 5 – when his scouts found Nagumo's fleet late afternoon only 180 odd miles away – and he positioned for a night strike... only to have Nagumo serendipitously reverse course just in time.]

2. Air strikes

The IJN would still have a considerable advantage in purely carrier versus carrier planes... in daylight. At least 50% more carrier borne aircraft, and the RN's strike aircraft were far more effective at night, and far too vulnerable to use during the day. (They would almost certainly have been as easy to swat out of the sky had they been risked in a daylight attack, as the Devastators were at Midway.)

Though probably this number advantage would not be enough of to overcome the radar guided fighter intercepts that had seen British multi-carrier forces hold off literally hundreds of combined German and Italian fighters and bombers in the Mediterranean.  (See the Malta Convoys in general, and the particularly good descriptions of the aircraft carriers fighting off 456 German and 358 Italian land based aircraft on August 12 in Operation Pedestal... An operation that simply would not have happened unless the IJN had been smashed at Midway or Ceylon). 

On the Pedestal convoy, Victorious, Indomitable and Eagle, used only 72 fighters on rotating patrols  to fight off 714 enemy aircraft. Assuming Indomitable and Eagle had slightly smaller loads at Ceylon in June, and Victorious' sisters Illustrious and Formidable also had a slightly smaller loads: that would give the RN about 80-85 fighters for this 'Midway' battle. But instead of facing 714 land based planes that knew exactly where the convoy was all day long, (and didn't have to protect their airfields in the process); they would only face 240 Japanese aircraft, (some of which had to stay and protect their own carriers). And the Japanese would have no accurate intelligence about where the British fleet might be, and would have to mount Coral Sea/Midway type sweeps to find them... (Note, at Midway the 3 USN carriers also had about 80 fighters, but unfortunately lacked the experience with radar intercepts to use them anywhere near as effectively.)

The IJN's best bet obviously remained a surprise day attack by this experienced and skilled air strike arm. But whether they would get it is very doubtful. They still had to find the enemy, and then co-ordinate strikes; and then not get lost en-route; and then fight past the radar guided CAP; and the vast RN AA. (Again, while the USN still followed interwar doctrine and separated it's carrier task groups, the IJN and RN concentrated them for maximum AA and AS protection. See more on AA below.)

Frankly by this stage the RN had so much experience with radar interception and holding off much larger German and Italian air strikes with relatively small CAP's, that it seems highly unlikely that the sorts of attacks the Japanese succeeded with at Midway would have had much chance getting similar results against the British fleet. 

[In fact even the IJN having 6 carriers rather than 4 probably wouldn't be enough to balance the technical odds. Even if we reversed the starting premise of the same forces as were used at Midway, and said Shokaku and Zuikaku were still undamaged after finishing off the USN; and still had enough functional air group to be able to support the other 4 carriers: the technical odds against the Japanese would still require considerable luck to overcome RN technology and experience. 2 Extra flight decks and a 50% increase of 100 to 120 extra planes would certainly help the odds a bit, but the IJN would still need the series of multiple lucky breaks the USN had at real Midway to gain a victory.]

Nor would any RN strikes led by radar equipped torpedo bombers suffer from the hopeless/helpless wandering around and getting lost that both the IJN and USN air strikes suffered from at Coral Sea and Midway. (That saw dozens of planes run out of fuel before finding anything, or simply fail to get back before getting lost in the dark, or even trying to land on each others carriers!) Day or night, RN strikes could find their targets, and usually had a very good percentage of hits if they did get through. (Plus, their torpedoes actually worked... unlike those of the poor Devastator pilots who survived the slaughter at Midway long enough to actually launch against Japanese carriers!)

But note that Somerville definitely didn't want to risk his slow and vulnerable torpedo bombers by day... He wanted to be in position to do an ambush strike at night. 

3. AA defenses...

The combined AA of the 4 Jap carriers and the 2 escorting battlecruisers was probably less powerful, and certainly less effective, than that of a single Illustrious class carrier, or of the modernised battleship Valiant. To be blunt, Jap AA sucked. (In fact the main IJN 25mm AA gun was a practically useless waste of space compared to the far superior 40mm and 20mm medium and short range weapons of the Allies, and certainly couldn't defend either ranges adequately, let alone try and manage both ranges. Only the equivalent USN 1.1" – which still made up the majority of USN capital ship and cruiser weight AA at Midway – was a worse AA gun than the 25mm.)

By contrast for the RN the modern AA batteries of the 3 British carriers, and the Valiant, amounted to 68 4.5" guns and there were more than 50 odd almost as effective 4" guns (both models having approximately equivalent rate of fire, and considerably better range, than the quite excellent 5"/38 on the newer USN ships). Let alone over 100 less effective 4.7" and over 300 2 pounder pom-poms and hundreds more 20mm and .50 MG's on the other RN ships in the fleet. (Particularly note the specialist Dutch AA cruiser Jacob van Heemskerk). 2 years of quite painful war experience had paid off for the RN. There was much more, much better, and much better directed, AA firepower on just the capital ships and cruisers of the Eastern Fleet, than in the entire Japanese navy put together at that time. 

But keep in mind, Somerville – with superior intel and the advantage of radar – was trying to avoid this sort of day action... His AA capabilities were really only a safeguard part of the backup plan, and preferably not even relevant to his ambush plan. However, given the – still unrecognised – range advantage of Japanese carrier aircraft, it was a very useful backup. Even if his night attack had taken 3 carriers as happened at Midway, that would still leave Hiryu's counter attack to deal with in the morning. And if the night attack hadn't managed to damage all 3 carriers, perhaps only getting one or two of them: then even if he fell back on the support force in daylight, they very probably wouldn't be out of range of some sort of counter-attack.

The Eastern Fleets AA firepower would have been an excellent security blanket.

4. Night Fighting

Although the IJN surface fleet had trained extensively for night fighting, the IJN's carrier arm was not capable of night operations. And of course, the IJN had virtually no radar (though Kaga for one had received a very simple set during her April refit that caused her to miss the Indian Ocean raid, not that it helped at Midway). The IJN also had absolutely no practical experience of using radar in combat. 

[The USN, still amateurs at radar in combat, weren't really trained to fight at night full stop at the time of Midway. See Savo Island for a good discussion of that issue...]

The RN of course, had extensive combat experience day or night, and lots of that combat experience had involved radar directed operations of all sorts. From night ambushes by surface units like Cape Matapan and Force K (particularly the Duisburg convoy battle); and night strikes by aircraft like at Taranto and the Bismarck. And the Japanese had no answer at all to the British radar guided torpedo bombers at night. (They might be old fashioned looking biplanes, but if they can find and sink you when you can't even see them coming, you are at a considerable disadvantage.)

Which is why Somerville planned his April ambush around his fast force making a night strike, and retiring on the slow force in daylight.

The difference is that by June he would probably not even need to retire on his Slow Force. The Fast Force alone could handle anything Nagumo's Strike Force could offer, and only the arrival of Yamamoto's Main Force might require support from the Slow Force to deal with.

5. Surface Action?

Well it did happen quite a bit during the war, from Narvik to the Bismarck action to the North Cape: from Calabria to Cape Matapan; and from Guadalcanal to Surigao Strait to Malacca Strait. So let's assume it could happen here.

If the IJN Strike Force had only the 2 Kongo class battlecruisers they actually had at Midway, then they simply could not take on either the British Fast Force or Slow Force separately with any real chance of winning. Certainly not if they happened to be in company.

Frankly I would like to think that Japanese dispositions would be more sensible for an attack on Ceylon than the 3 (or 4 if you include the Aleutians group),widely dispersed forces at Midway. Given that at Midway the Strike and Main forces both come roughy from Japan, whereas the invasion force comes from much further south, it is quite reasonable that two of the Japanese battlecruisers and 2 light carriers were diverted for protecting and supporting the invasion force. But for a Ceylon battle all the forces would all be coming pretty much from the same direction, so why not a bit more concentration?

Let's say the 27 knot Yamato, Nagato and Mutsu with their 2 covering/invasion supporting light carriers cover the actual invasion force (if there is one... maybe they are out of resources for land ops if they have occupied Hawaii etc). Or at least form the traditional Japanese Support Force/covering force/ Main body/whatever coming along behind the Strike Force. That allows all 4 of the 30+ knot Kongo class battlecruisers to be with Nagumo's fast carrier strike fleet, the way they actually were in the April Raid. In theory those 4 working together might be willing to take on one of the RN forces. (And their speed would give them the option to run from superior numbers anyway.)

Unfortunately the IJN's extremely vulnerable Kongo class battlecruisers (with only 8" belts - inferior to even the WW1 battlecruisers lost at Jutland) could simply not risk facing real battleships in slugging matches. Re-naming them 'fast battleships' during the 1930's could not disguise their lack of armour. And even the IJN's vaunted night fighting training probably couldn't have saved if they came anywhere near the radar guided British battleship guns. (Frankly it would take Kamikaze runs by IJN destroyers armed with the lethal Long Lance torpedoes to try and even the odds... and too many of the British cruisers and destroyers tasked with stopping such attacks had radar too...)

A surface action between the 4 Kongo's and the 2 Nelsons supported by 3 Queen Elizabeths could only have one outcome... even without the 4 Revenge class being close enough to be in support.

Fantasy Stuff, for the fun of it...

But what if the Japanese had actually really concentrated for once? If they abandoned the 'multiple forces converging from multiple directions' approach they used at Coral Sea, Midway, Philippines Sea, Leyte Gulf, and almost every battle in between: and actually sent Yamamoto's main body in as a close support force for Nagumo's strike fleet? Then you would have both sides using fast forces supported by slow forces, both of which contained both carriers and battleships/battlecruisers.

The result of that would effectively be the Battle of the Leyte Gulf, but in June 1942. What fun!

It is amusing, if unrealistic, to imagine a fleet action with the IJN's 7 battleships and battlecruisers in line against the RN's 9 battleships. The Japanese would have a clear speed advantage, but, even allowing for Yamato's 18" guns, the RN would have a substantial advantage in firepower and in weight of armour protection across the board. Only Yamato had armour at the levels of the British ships (see my pretty detailed discussion of armour quality versus quantity here), with even the Nagato's quite lightly protected by British standards. And the Kongo's were practically defenceless against heavy shells of any sort. 

Let alone the RN's considerable accuracy advantage based on their radar and superior gunnery in general. A post war USN report noted that the RN's 15" guns were the most reliable and accurate big guns of the war. Warspite for instance had achieved the longest range hits against another battleship in history - 25 miles - at Calabria, (and the Scharnhost got hits from a similar range against the carrier Glorious the same year.. with 11" guns!).. The longest range Japanese 'hits' ever recorded were some near misses in perfect daylight conditions, by the Yamato at 19 miles in 1944, that nevertheless sunk an escort carrier. (Though I'd be interested if someone can quote a longer range hit?)

Even in clear weather, and in daylight, the RN would have a significant advantage in a pounding match. In poor visibility conditions, or at night, with radar direction, the RN's advantage would be completely overwhelming. That would probably still be the case even if the 4 Revenge's were not within range, and the 5 British battleships of the Fast Force engaged the 3 IJN battleships and their 4 battlecruiser supporters simultaneously. 

But that is vanishingly unlikely.

In reality the two sides fast and slow squadrons would be manoeuvring around each other more like the various squadrons at Jutland, than the crashing lines at Trafalgar. And the problem with that is that even if the Japanese Strike Force's Kongo's accidentally got through to attack the Revenge's in the Slow Force, they would probably lose; and if they more realistically met the British Fast Force head on, they would definitely lose. Their only chance was to try and lure the Fast Force back into range of the Yamato and the Nagato's... where, excepting a striking bit of luck, they would still probably lose.

Even the vaunted Yamato supported by a couple of Nagato's, doesn't stand much of a chance against a pair of radar equipped Nelson's supported by 3 radar equipped Queen Elizabeths.

Re-emphasising that 'two front' dilemma

In reality the IJN tried to win just enough against the USN at Pearl Harbour to keep them unable to respond for a while; then rush over to try and beat the RN badly enough in the Indian Ocean to clear the threat to that flank; in time to rush back and finally defeat the USN at Midway. In reality all 3 attempts failed to achieve their goals.

To use a baseball term, "Three strikes and you're out"...

The alternative solution suggested here is that they should have just left a minimal screen against the RN for a few months; spent the time to properly eliminate any immediate threat from the USN; and then been able to turn their full resources to properly defeating the RN on the other flank.

Problem is, as the above makes clear, that probably wouldn't have worked either.

There can't be much doubt that by the time the USN had been comprehensively defeated, and the somewhat weakened IJN finally turned to face the RN, the British buildup would have been too great for the Japanese to have much chance of victory.

In other words, regardless of which allies absorbed the damage during the crucial 6 months in the process of preventing the Japanese claiming a decisive victory, the end result was always going to be allowing the other ally to build adequate strength to face the Japanese.

In reality it seems that the IJN's best result was what they actually did. Disabling the USN temporarily; then disrupting the British buildup before it was complete (with at least a chance of a decisive victory there); and then getting a better than even chance shot at the USN at Midway, (where a proper concentration of forces might still have given them a victory.)

By contrast if they had taken that few extra months to occupy Hawaii, attack the US West Coast, and seek and destroy any remaining USN in the Pacific: the RN would have been given the time it needed to build practically unassailable strength in the Indian Ocean.

Frankly, it seems likely that if the IJN had concentrated on the USN for months and left the RN relatively untroubled, it would actually have worked out worse for the IJN in the long run.

Friday, June 11, 2021

Pearl Harbour - the follow up invasion plan

In the afternoon of December 7, 1941, Admiral Nagumo's staff debated whether a third strike should be made on Pearl Harbour?

The answer should have been, "Yes, we must completely control the air before Admiral Yamamoto arrives with the main body and the invasion fleet..."

That after all, had been the original plan supported by Fuchida and Genda and many others...

This fun little conception started from my previous post, which looked at how the Battle of Midway might have turned out if Japan had not been attacking Britain, Thailand, the Netherlands and Australia as well as the US, and had actually concentrated her forces on a proper defeat of the US.

In that article I started with Midway at the time of Midway, but without the distraction and attrition of fighting Britain, the Netherlands and Australia over the prior six months.

Obviously, the results would not have been good for the USN.

Then I considered the likelihood's of having to fight the 'decisive battle' earlier, say at the time of Coral Sea (May); or of the Indian Ocean Raid (April); or of the Darwin Raid (March); or of the Java Sea (February); or of the Makassar Strait (January).

But when I actually looked at alternative Japanese plans, it became clear that the real challenge would have been if the Japanese had followed through on their proposed invasion of Hawaii in the first attacks.

Here is the summary of that option from my last article:

Pearl Harbour, but no allies

If Japan wasn't trying to attack everywhere at once, and could concentrate the forces allocated against the British, Thais, Burmese and Dutch against the US, why not follow through? Even Nagumo would have been willing to take a third strike against Pearl in these circumstances. Particularly with his boss Yamamoto and his main body (with more support tankers) were following close behind, and carrying the 3 crack divisions no longer needed to invade for Malaya for an invasion of Hawaii! 

It is worth quoting the entire Wikipedi entry on the planned Japanese invasion (referenced 11 May, 2021):

Concept of a Japanese invasion of Hawaii[edit]

At several stages during 1941, Japan's military leaders discussed the possibility of launching an invasion to seize the Hawaiian Islands; this would provide Japan with a strategic base to shield its new empire, deny the United States any bases beyond the West Coast and further isolate Australia and New Zealand.

Genda, who saw Hawaii as vital for American operations against Japan after war began, believed Japan must follow any attack on Pearl Harbor with an invasion of Hawaii or risk losing the war. He viewed Hawaii as a base to threaten the west coast of North America, and perhaps as a negotiating tool for ending the war. He believed, following a successful air attack, 10,000-15,000 men could capture Hawaii, and saw the operation as a precursor or alternative to a Japanese invasion of the Philippines. In September 1941, Commander Yasuji Watanabe of the Combined Fleet staff estimated two divisions (30,000 men) and 80 ships, in addition to the carrier strike force, could capture the islands. He identified two possible landing sites, near Haleiwa and Kaneohe Bay, and proposed both be used in an operation that would require up to four weeks with Japanese air superiority.[40]

Although this idea gained some support, it was soon dismissed for several reasons:

  • Japan's ground forces, logistics, and resources were already fully committed, not only to the Second Sino-Japanese War but also for offensives in Southeast Asia that were planned to occur almost simultaneously with the Pearl Harbor attack.
  • The Imperial Japanese Army (IJA) insisted it needed to focus on operations in China and Southeast Asia, and refused to provide substantial support elsewhere. Because of a lack of cooperation between the services, the IJN never discussed the Hawaiian invasion proposal with the IJA.[40][g]
  • Most of the senior officers of the Combined Fleet, in particular Admiral Nagano, believed an invasion of Hawaii was too risky.[h][40]

With an invasion ruled out, it was agreed a massive carrier-based three wave airstrike against Pearl Harbor to destroy the Pacific Fleet would be sufficient. Japanese planners knew that Hawaii, with its strategic location in the Central Pacific, would serve as a critical base from which the United States could extend its military power against Japan. However, the confidence of Japan's leaders that the conflict would be over quickly and that the United States would choose to negotiate a compromise, rather than fight a long, bloody war, overrode this concern.[i][41][42][43]

Watanabe's superior, Captain Kameto Kuroshima, who believed the invasion plan unrealistic, after the war called his rejection of it the "biggest mistake" of his life.[40]

What if the invasion had gone ahead?

My previous article assumes that Japan didn't attack Britain and the Netherlands and concentrated on the US instead.

But in fact the plan outlined above just diverted some of the resources from the Philippines invasion, while leaving the other operations in place. 

(This would be a version of 'Island Hopping' in reverse... leaving the isolated Philippino garrison to 'wither on the vine', and for easy clean up later... In fact a slightly larger scale version of what actually happened anyway. Where, after the surprisingly easy conquest of Luzon, and the rapid retreat of MacArthur's forces to Bataan: the Japanese pulled most of their best units for other operations against Malaya, Burma and the East Indies for several months. Only returning to finish off the isolated Bataan/Corregidor garrison at a convenient time five months later. So this 'Hawaii first' option would just be a slightly larger version of the same strategy.)

So what was the actual goal of the Pearl Harbour operation? 

Piss off the Americans? Tick.

Win a tactical advantage to prevent interference in expansion operations? Tick.

Inflict a comprehensive defeat on the USN? Half a tick.

Destroy Pearl Harbour as an operational base? Fail.

Inflict enough damage to prevent counterattack for years? Fail.

Drive the entire USN out of the central Pacific and back to the US West Coast? Fail.

Allow a genuine threat of air and bombardment raids on the US West Coast? Fail

Win a strategic victory that would give a chance of negotiated peace? Fail.

Frankly, if you are going to kick a sleeping giant awake, best to kick it hard enough to put it out of action for years, and give you a chance of genuine negotiation. 

Not just enough to temporarily inconvenience it, and annoy it enough to invite massive retaliation.

In other words, either go full out, or don't do it at all!

"If you insist on doing this damn silly thing, don't do it in this damn silly way". (Sir Humphrey Appleby on Yes Minister.) 

The plan to weaken, and temporarily incapacitate the main USN fleet, was sensible enough. It may have looked risky, but it was a proven tactic.

Again, we can quote the Wikipedia article on Japanese Planning for the Pearl Harbour attack:

Several Japanese naval officers had been impressed by the British action in the Battle of Taranto, in which 21 obsolete Fairey Swordfish disabled half the Regia Marina (Italian Navy). Admiral Yamamoto even dispatched a delegation to Italy, which concluded a larger and better-supported version of Cunningham's strike could force the U.S. Pacific Fleet to retreat to bases in California, thus giving Japan the time necessary to establish a "barrier" defense to protect Japanese control of the Dutch East Indies. The delegation returned to Japan with information about the shallow-running torpedoes Cunningham's engineers had devised.[citation needed]

The technical aspects of the plan were perfectly sensible, and in fact it worked.

However the more sensible advocates of the plan had expected it to at least involve the third strike against the oil supplies and dockyard facilities that would have put the base out of operation... (Wikipedia - Attack on Pearl Harbour - referenced May 18, 2021.)

If they had been wiped out, "serious [American] operations in the Pacific would have been postponed for more than a year";[117] according to Admiral Chester W. Nimitz, later Commander in Chief of the Pacific Fleet, "it would have prolonged the war another two years".[118] 

At a conference aboard his flagship the following morning, Yamamoto supported Nagumo's withdrawal without launching a third wave.[123] In retrospect, sparing the vital dockyards, maintenance shops, and the oil tank farm meant the U.S. could respond relatively quickly to Japanese activities in the Pacific. Yamamoto later regretted Nagumo's decision to withdraw and categorically stated it had been a great mistake not to order a third strike.[125]

That decision in itself made the entire operation of dubious value. Temporary advantage gained at immense cost (in pissing of the US): when real advantage could have been gained with just a little more effort.

There are justifications for Nagumo's decision:

Nagumo, however, decided to withdraw for several reasons:

  • American anti-aircraft performance had improved considerably during the second strike, and two-thirds of Japan's losses were incurred during the second wave.[119]
  • Nagumo felt if he launched a third strike, he would be risking three-quarters of the Combined Fleet's strength to wipe out the remaining targets (which included the facilities) while suffering higher aircraft losses.[119]
  • The location of the American carriers remained unknown. In addition, the admiral was concerned his force was now within range of American land-based bombers.[119] Nagumo was uncertain whether the U.S. had enough surviving planes remaining on Hawaii to launch an attack against his carriers.[120]
  • A third wave would have required substantial preparation and turnaround time, and would have meant returning planes would have had to land at night. At the time, only the Royal Navy had developed night carrier techniques, so this was a substantial risk.[121]
  • The task force's fuel situation did not permit him to remain in waters north of Pearl Harbor much longer since he was at the very limit of logistical support. To do so risked running unacceptably low on fuel, perhaps even having to abandon destroyers en route home.[122]
  • He believed the second strike had essentially satisfied the main objective of his mission—the neutralization of the Pacific Fleet—and did not wish to risk further losses.[123] Moreover, it was Japanese Navy practice to prefer the conservation of strength over the total destruction of the enemy.[124]

But some of these look remarkably like retrospective excuses. In practice losing even half the IJN's carrier plane fleet to completely destroy Pearl Harbour as an operational base would have been infinitely more valuable than this half arsed effort that invited swift and sustained counter attack.

I realise Nagumo's decision could, at least theoretically, be seen as part of a clever long term plan for weakening the USN by attrition as you reeled it in for the final battle where the IJN battle fleet would be able to deliver a coup de gras, but frankly that is fantastically unrealistic thinking. If you can't capitalise on the overwhelming success of actual surprise attack, then you certainly won't be able to make your enemy follow your beautiful little theories to the letter to enjoy their inevitable defeat!

I have said it before, and will say it again. Nagumo was a terrible Admiral, and repeatedly managed to snatch slow agonising long term defeat from the jaws of astonishing short term victories.

A real victory - invasion of Hawaii

After a third wave on December 7 that concentrated on reducing active resistance, the job of the fourth and fifth waves on December 8 would have been purely air superiority over the island, as there would have been no need for further air-strikes against Pearl Harbour itself.

There would have been no need, because half a dozen IJN battleships – most likely the two 27 knot Nagato's and the four 30+ knot Kongo's, (escorted by the 7th aircraft carrier Hosho), that actually did provide distant cover for the operation – would be giving an object lesson as to what Mers-el-Kebir could have looked like if Somerville hadn't consciously decided to do as little damage as possible. 

There is not much doubt that the 48 14" and 16" guns of those 6 capital ships could finish the operational destruction of both the US Pacific fleet and the Pearl Harbour base in pretty short order if the IJN controlled the air. (If they wanted to... perhaps leaving the dockyards an oil tanks intact for the invasion force to gather in would have been preferable? In fact it is amusingly possible to re-imagine the Doolittle Raid actually taking place as a USN strike against the captured ships and facilities of an occupied Pearl Harbour!)

In fact the only real threat to a Japanese invasion fleet was potentially any USN submarines that might a) survive, b) manage to get to sea, and c) manage to get past a massive IJN air and surface screen to attack fast moving targets... (Let's be optimistic and suggest that one of them did actually hit one of the Japanese capital ships, and by some miracle the torpedo functioned... unlikely at that time... and damaged, but did not sink it... that is what actually happened later in the war... once the torpedo's were fixed anyway... so let's say it happened almost accidentally here... big deal... Particularly if the damaged ship could sail straight into an occupied Pearl harbour for repairs?)

But the key element of the bombardment of Hawaii by the IJN would not actually have been doing further damage to the port facilities or the disabled ships, which by this point would actually be targets for capture. It would really be counter battery work (along with a dozen cruisers and two dozen destroyers), for suppressing any guns that might try to interfere with the invasion fleet landing two divisions on the morning of December 9 1941.

But by that time the IJN aircraft and surface fleet would have almost completely suppressed much useful resistance, leaving the elite battle hardened Japanese divisions to sweep aside the poorly equipped and badly trained defenders, who might be determined, but whose devastated morale and complete lack of combat experience would quickly tell.

You can fantasise as much as you like about iron jawed John Wayne types mounting a furious resistance, but, to use a phrase, it doesn't amount to a 'hill of beans' when it comes to battered amateurs against experienced professionals with full air and sea dominance and massive fire-power support. If something as strong and well garrisoned as Fort Eben-Emauel can fall to such a shockingly fast and powerful attack, then certainly an unprepared Hawaii can! Singapore was much better prepared, and much more heavily garrisoned 2 months later, but, stuck in a civilian disaster zone, they had no real chance against crack troops with complete dominance of air and sea.

If Japan had  made any serious attempt to follow up with an invasion of Hawaii, then it is almost inconceivable that Hawaii would not have fallen.

Could the Lexington and Enterprise have intervened?

If the Japanese Strike Force had hung around instead of leaving, and the Japanese main body and invasion fleet were about to arrive and start further operations: it is hard to imagine the nearby American carriers not trying to intervene? (Though it would probably be more sensible for them to run for the US West coast instead.) 

[Saratoga was actually entering San Diego harbour when the attack started, while Lexington was near Midway and Enterprise had just sent 18 of her Dauntless's to Pearl that morning - and had most of them shot down either by a combination of the Japanese fighters and US AA!]

But even had the two carriers actually available been able to link up and co-ordinate somewhat, they could hardly be in organised position to strike back much before the main body (with 6 capital ships, a seventh carrier, a dozen cruisers, and 2 or 3 dozen destroyers) arrived. It is also worth noting that Lexington for instance was still equipped with just 17 Buffalo fighters at this stage! Buffalo's!!! 

The USN , could still only really fight in daylight, unlike the IJN, which could also fight at night. (Or the RN, which could fight at night by both surface and air attack... The USN and  IJN still lacked the radar guided torpedo bombers the RN had to make air attacks at night possible.) 

Both US carriers together, fielding less than 40 fighters, half of them Buffalo's... against 147 Zero's... in daylight... And their Devastator torpedo bombers lacked a functional torpedo! It would be entirely down to  perhaps a couple of dozen Dauntless dive bombers against 7 Japanese carriers and probably 6 battleships and God knows how many cruisers, destroyers and submarines as well.

In reality we get this (Wikipedia article on Enterprise sourced 30.4.2021):

Enterprise received radio messages from Pearl Harbor reporting that the base was under attack, and she was later directed to launch an airstrike based on an inaccurate report of a Japanese carrier southwest of her location. The strike was launched around 17:00, consisting of six Grumman F4F Wildcat fighters of Fighting Squadron Six (VF-6), 18 Douglas TBD Devastator torpedo bombers of Torpedo Squadron Six (VT-6), and six SBDs of VB-6.[12]

Six dive bombers against 6 Japanese carriers! The Devastators without functional torpedos are mere distractions. Even had Lexington rendezvoused next day for a joint strike, her 58 total bombers and torpedo bombers also come down to less than a couple of dozen extra dive bombers. Say 30 dive bombers and 40 fighters in total together against practically the entire Japanese navy? That's not even the size of a single strike from either Coral Sea or Midway, and with less advanced planes and way less experienced crews against the Japanese at peak numbers and efficiency!

It is very hard to see any combination of fantastic flukes that might make this a winning proposition for the USN.

Frankly it doesn't bear thinking about.

What else might the Japanese have done, if truly committed.

Occupying the Hawaii islands and bases would be a good start. Particularly if the Americans were in such chaos that they didn't manage to destroy all the oil tanks, dockyards and their supplies, and finish the sinking (or flat blow up) their disabled ships. 

It is actually amusing to imagine the Japanese salvaging and returning to service half a dozen of the less damaged US battleships.

The result would definitely have driven the remnants of the US navy back to the West Coast of the US, and thus allowed the occupation of Midway and the Philippines at leisure. In fact places like Guadalcanal could be swept up later with no opposition worth mentioning. The Australians or New Zealanders might have tried to send a battalion or so, but with US naval support cut off, it would be many months before any substantial reinforcements from Britain or the Eastern Fleet would interfere with the IJN doing what it liked in the South Pacific. Port Moresby would probably have fallen for instance.

What about the America's themselves?

The I-400 class submarines, specifically designed to allow submarine born bombers to attack places like the Panama canal, were not even designed yet... but they certainly reveal Yamamoto's thinking.

At the very least, a couple of Japanese submarines could have made an effort to shell the Panama Canal at the time of the attack on Pearl Harbour. With the objective of sinking a ship in a vital place.

More dramatically, an actual block-ship might have been sacrificed. It would have been easy enough to position an old freighter - possibly flagged as if from China or Thailand - during peacetime, at a place where it might have caused considerable damage. Whether it might have been possible to have it actually transiting the canal during the vital point (admittedly the middle of the day peak time for transit), so that it might take out a lock and do serious damage... well that might be optimistic. But it comes pretty close to what the Germans did with pre-positioning ships in their surprise attack on Norway during peacetime, so not necessarily unfeasible.

The question is, how much follow up could the IJN put into strikes against the US West Coast itself?

Obviously no invasion could be contemplated. But arguably the efforts put into at least some of the Darwin Raid, Indian Ocean Raid, Coral Sea and Midway operations: would have been better put into smashing the USN's remaining Pacific reserves (particularly if Panama had been closed). And into attacking both Californian port facilities and industry. Specifically, Californian naval shipyards and aircraft factories.

The argument against this is that the IJN had to remember it was facing a two front war, and be constantly prepared to face the British Eastern Fleet. In fact the whole point of the Darwin and Indian Ocean raids was to try and destroy, or at least limit, that threat.

But in this scenario, it would be far easier to completely finish off the threat from the USN (at least for several years), while reversing the 'final battle' strategy for use against the RN instead. With the USN reduced to impotence, and the main Japanese fleet based at Singapore (which it actually was sometimes, even under the two front threat), then the IJN had a chance of enticing the British into a decisive 'Battle of Tsushima' in mid to late 1942. 

Consider a Midway style operation aimed at forcing the British Eastern Fleet to fight at Ceylon, but with no effective USN to threaten its flank? If the Japanese have garrisoned Hawaii and Midway already, and done a couple of Darwin/Indian Ocean style raids on the US West Coast (hopefully reducing the USN to one active carrier the way they actually did in late 1942 anyway), then such a Midway style operation might not even lack Shokaku and Zuikaku? Admittedly the attrition rates of such a series of attacks would still see much reduced squadron numbers, and a lot of less skilled pilots, in the Japanese carriers. But it is still a sobering thought.

Success in negotiating peace?

This is a fun thought. If the USN has been neutralised, then obviously Japan would have to attempt to knock out the Eastern Fleet and make the Allies admit that a negotiated peace is the only alternative.

Frankly part of the plan to occupy Hawaii was the assumption that trading it back in return for peace would be a major attraction to the US. So peace in return for safety for US, New Zealand, Australia, India and Ceylon. With the bonus of the return of Hawaii and Burma, and possibly a neutralised zone Singapore under joint management. All offered when the IJN has achieved total victory, and there is nothing the US or Britain can do about it.

Given that Britain and Russia are still in a desperate struggle against Germany and Italy, it is hard to see what Britain could do about it if the US can't provide any useful support.

But that requires the IJN to defeat the British Eastern Fleet as well as the US Pacific Fleet. and the longer operations continued against the USN, the less chance the IJN would have to catch the Eastern Fleet vulnerably incomplete.

(I think my next article will have to be on 'would a US first strategy have worked any better? for Japan'...)

Let's just re-emphasise the concept of 'allies' here.

Frankly, had the Japanese felt safe to attack the British and Dutch without risking US entry to the war, they would have probably won well enough to force a negotiated peace. But of course they couldn't safely assume that Roosevelt couldn't overcome US isolationism. The USN, particularly based in the Philippines, could simply have cut Japan's supply lines to China and the new operational zones further south any time they felt like it.

Likewise, had the Japanese felt safe to attack the US without fearing British entry to the war, they would probably have won well enough to force a negotiated peace. But of course they knew the British would know who was next in line if the USN collapsed, and that the British would understood absolutely the need to do everything possible to keep their allies in action. (Even Stalin...)

Japan's problem was that they couldn't risk seizing British and Dutch possessions without dealing with their vulnerable flank against the US.

Equally, they couldn't risk dealing with the US without opening their vulnerable flank against the potential British counter operations.

However it is interesting to speculate on whether it would have been more sensible for the Japanese to concentrate their first few months on the Americans, simply assuming the British would not be in any position to mount a counter threat for many months? A pretty realistic assumption in early 1942.

Could that have been more effective than splitting Japanese forces between simultaneous operations against everyone simultaneously?

In reality of course, we know that the impressive looking efforts careening all over 1/3 of the globe trying to take out the USN at one end and the RN at the other end: just meant that neither was really defeated badly enough to be driven from the field. Worryingly strong forces remained to mount Doolittle raids, invasions of Madagascar, and attacks on the Andaman's, or around New Guinea or Guadalcanal. This just lead the IJN rushing backwards and forwards to more and more frantic attempts to achieve 'decisive' results here or there, usually be ever decreasing numbers of planes operating from less and less carriers each time.

The Great Mistake...

In reality, I don't think there can be much doubt that the Japanese screwed up in not following through at Pearl Harbour.

Both Yamamoto and Nimitz stated categorically that a third strike to finish off the dockyards and oil storage at Pearl Harbour would have greatly improved the Japanese position, and slowed US efforts at striking back by at least 2 years.

But the real missed opportunity might have been the invasion of Hawaii. 

Let's have that Wikipedia quote again...

Watanabe's superior, Captain Kameto Kuroshima, who believed the invasion plan unrealistic, after the war called his rejection of it the "biggest mistake" of his life.[40]

Saturday, May 8, 2021

If Japan had attacked the US, but not Britain – An earlier Midway?

 If Japan had attacked the US, but not Britain - An earlier Midway?

This fun little concept comes from my previous articles about what would have happened if Britain and France had not gone to war with Germany in September 1939, and instead a war had started about December 1941. This needed so much back story analysis that there are 6 articles in the series so far, but here is some of the summary from the last one, which led to me considering this little question in a bit more detail.

A weird and wonderful bag of possibilities. Enjoy.

We will start with a recap of my previous article...

So is there any chance of a World War starting in December 1941 instead.

No, not in the form we know it.

But yes, definitely in the form of a German and Japanese alliance against Russia.

After all, that would be both more possible, and more attractive, given the changing balance of naval power.

But does that become a world war? Could such a simple war start have led to 'complications'.

Would Britain or France have gone to war to save Stalin's Communist dictatorship in such circumstances? It seems unlikely. (Nor would the Dominions have been keen to go to war for Stalin.)

More interestingly, would the US have eventually decided to try and intervene on China's behalf? Unlikely given US isolationism, but I suppose it is possible to conceive of the US going to war with Japan over China. After all, it was ever increasing US pressure and sanctions over China that effectively convinced Japan it had to take on the US (and almost incidentally the British and Dutch) in 1941.

This then provides the amusing picture of the US deciding to fight Japan over China while Britain and France are still neutral. (It may be hard to imagine the US actually taking the lead in anything given their domestic politics, but it parallels what they actually did in 1941.)

In which case, perhaps it would even exceed the same disastrous results that the US managed to achieve in reality? Without any allies to distract the vast majority of the Japanese military into land and sea operations in Malaya, the East indies, Burma, Rabaul, New Guinea and the Indian Ocean, there would be no need to divert most of the best Japanese units in other directions. Leaving only the barest screen against the British/French/Dutch navies (which in this situation might actually outnumber the IJN anyway), the Japanese could have concentrated their battle hardened forces on the inadequately prepared Americans instead.

Stupidly risky thing for Japan to do, but again, reflecting the unrealistic risks that Japan really took anyway... 

So lets start playing with a few options...

A 'Battle of Midway' without any allies to delay and run interference?

Given how completely the US position in Asia collapsed in early 1942 – even with Britain, Australia, India and the Netherlands taking their side and fighting long and hard against the cream of the Japanese forces for 6 months – it is scary to imagine what the Japanese could have achieved without all that distraction. 

Instead of just complete disaster at Pearl Harbour; the retreat of their surviving battleships to the West Coast; and the loss of the Philippines and most of their Pacific Islands; the US may have also suffered the equivalent of the combined British and Dutch losses in the first six months of the real war as well... (Add 2 more battleships, 1 aircraft carrier, several cruisers and dozens of destroyers, plus half a dozen British, Indian or Australian divisions and another 10 Dutch East Indies divisions, and several hundred more fighters and bombers... to the US's already impressive losses - particularly the dozen divisions and hundreds of aircraft in the Philippines, and the various island bases. Now try and imagine what the US would have left to defend Hawaii?)


And that is only if Hawaii hadn't been invaded in the first round using the 3 crack divisions that in reality attacked Malaya. 

The Japanese had actually completed plans for such an invasion of Hawaii, and only actually needed 2 divisions to make it work! (In reality the Japanese Army said it couldn't spare the resources given the other operations needed against the British, Dutch and Australians... but if those operations weren't needed? Indeed, even if they were still needed, the effects of a successful invasion in December 1941 would have been mind boggling. IJN Captain Kurishimo of the Japanese planning staff, who accepted the recommendation of his junior, Commander Watanabe, that invasion was too risky in these circumstances, later called that decision, the 'biggest mistake' of my life.)

But even if they hadn't committed to that up front, Midway Island almost certainly would have been captured at the same time as Wake and Guam, changing the entire strategic perspective way in advance of the actual battle of Midway.. 

Certainly the USN would have faced a complete and un-exhausted Japanese fleet at any final 'Battle of Midway', which presumably would have been fought either about the time of the battles of Rabual (23 January 1942); of Java Sea (28 February 1942), of Darwin ; or of the Indian Ocean Raid (5 April 1942): not months later (4 June 1942) after the Japanese had suffered long months of constant effort and attrition, and the US had had many extra months to prepare... 

Let's consider IJN carrier aircraft attrition over those 6 months for instance.

(I start with taking starting figures from Navweapons, apologies for mistakes, but it is generally a good rough guide (if I added correctly!) -

However I note that there are endless suggestions to how many planes were really on any given operation, with much disagreement in the documents. It is noticeable that the theoretical figures in Navweapons for the Indian Ocean raid assume full December 1941 squadrons, which is unlikely after 5 months of constant operations, and doesn't reflect some suggestions that squadrons had already been downsized a bit by the time of the Indian Ocean Raid. The figures certainly don't remotely fit with what Shokaku and Zuikaku were really carrying at Coral Sea, a few weeks later, after 6 months of operations. (After the Indian Ocean Raid the Japanese claim to have only lost 5 aircraft on the entire operation... British estimates are Zero 4 kill & 3 damaged, Val 6 kills & 7 damaged, Kates 2 kill & 12 damaged, for 34 kills or badly damaged... and some of damaged never made it back to a carrier to be repaired... let alone any operational losses... I have seen all sorts of weird numbers claimed, but again, estimates of substantial losses from already reduced squadrons seem to come a bit closer to reflecting how many planes the Japanese took into action at Coral Sea and Midway than the Japanese claim of only 5 losses from full squadrons...)

Pearl Harbour

Akagi – 27 Zero, 27 Kate, 18 Val = 72

Kaga – 27 Zero, 27 Kate, 24 Val = 78

Soryu – 27 Zero, 18 Kate, 15 Val = 60

Hiryu – 27 Zero, 18 Kate, 15 Val = 60

Shokaku – 15 Zero, 27 Kate, 27 Val = 69

Zuikaku – 24 Zero, 18 Kate, 15 Val = 69

Total – 147 Zero, 135 Kate, 114 Val = 396 (Theoretically, many sources say higher numbers – up to 423 in some cases; or lower – 359 in others. Almost 20% variation before we even start? This lack of clarity even before the IJN has had a single operational or combat loss, makes some of the later quoted variations of numbers highly suspect.)

Raid on Darwin (19 February, 1942)

(Navweapons doesn't cover it! Not really a battle? But Wikipedia suggests 188 carrier aircraft involved from Akagi, Kaga, Soryu and Hiryu – 36 Zero, 81 Kate, 71 Val – and suggests up to 32 were lost or damaged. This doesn't seem to work very well with Navweapon suggestion that all Japanese carriers were fully equipped with war start loads a few weeks later in the Indian Ocean Raid.)

Indian Ocean Raid (5 April, 1942)

(You can read a comprehensive summary of this series of skirmishes, but almost battle, here - - Interestingly, in the 'Order of Battle' section it lists the full theoretical numbers carried by each Japanese carrier - matching what Navweapons says, but this doesn't seem to relate well with the Darwin numbers or losses. But it also says "Some sources argue that due to losses due to combat (40 aircraft), deck landing and mechanical attrition since Pearl Harbour, the Japanese  carrier force had standardised their squadrons at 18 operational aircraft each to allow for spares. therefore Akagi at this time was operating 18 fighters, 18 dive bombers and 18 torpedo bombers for a total of 54".)

Navweapons totals (Armouredcarrier totals)

Akagi – 27 Zero, 27 Kate, 18 Val = 72 (Or 18 Zero, 18 Kate, 18 Val = 54)

Soryu – 21 Zero, 21 Kate, 21 Val = 63 (Or 18 Zero, 18 Kate, 18 Val = 54)

Hiryu – 21 Zero, 21 Kate, 21 Val = 63 (Or 18 Zero, 18 Kate, 18 Val = 54)

Shokaku – 18 Zero, 27 Kate, 27 Val = 72 (Or 18 Zero, 19 Kate, 19 Val = 56)

Zuikaku – 18 Zero, 27 Kate, 27 Val = 72 (Or 18 Zero, 19 Kate, 19 Val = 56)

Total – 97 Zero, 123 Kate, 114 Val = 342 (Or 90 Zero, 92 Kate, 92 Val = 274)

As usual, both options are little more than best guesses, though Navweapons suggestion of 100% squadron load after 5 months of constant operations, and the Pearl Harbour and Darwin losses, let alone normal operational or deck landing accidents, seems highly unlikely.

Coral Sea (4 May 1942)

Shokaku – 18 Zero, 21 Kate, 19 Val = 58 

Zuikaku – 20 Zero, 23 Kate, 22 Val = 65

Total – 38 Zero, 44 Kate, 41 Val = 123

(Note one month earlier these two ships had taken somewhere between 112 and 144 aircraft to Indian Ocean. If they took 144 to the Indian Ocean, and all 5 losses there were from just these 2 carriers, why are there only 123 left? If they took more like 112 (or somewhere in between) to the Indian Ocean, and there were 30 odd losses or write offs amongst the 5 carriers involved, then even allowing for replacements or transfers from other carriers returning to Japan for refit, 123 aircraft still seems optomistic? After this battle – and the Wikipedia article suggests that these two carriers (and Shoho and 2 some tenders), managed to lose 139 'carrier planes' in that battle! – they were too depleted/damaged to participate in Midway.)


Akagi – 24 Zero, 18 Kate, 18 Val = 60

Akagi – 27 Zero, 27 Kate, 18 Val = 72

Soryu – 21 Zero, 18 Kate, 16 Val = 55

Hiryu – 21 Zero, 18 Kate, 18 Val = 57

Total – 93 Zero, 81 Kate, 70 Val = 244

(Note - Akagi, after Indian Ocean Raid, is down to 60, whereas Akagi, which didn't go, is still at 72? Soryu and Hiryu, which both took 63 to Indian Ocean, or perhaps 54, are now on 55 and 57 respectively? These 4 ships, which had 270 expert pilots at Pearl Harbour, had 244 - including less experienced replacements - at Midway, and Shokaku and Zuikaku were too depleted to join them. 10% less numbers in those 4 ships alone – despite replacements, and almost 40% less overall aircraft/aircrews than their strike force had used at Pearl Harbour. Regardless of what numbers you finally accept, 40% reduction for the crucial battle compared to 6 months earlier is a clear case of attrition in action.)

For a little comparison of reality, Admiral Fletcher started the Guadalcanal campaign on 7 August 1942 with 99 Wildcats on 3 carriers - Saratoga, Enterprise and Wasp. It must be said that their first couple of days of operations were almost as successful as any other surprise attack by any other navy had been – say the British at Taranto or the Japanese at Pearl or Darwin. Nonetheless Admiral Fletcher notes he was down to 78 active fighters within 36 hours when he withdrew to refuel. That's about 21.5% casualties in a little over a day of successful  operations. Very successful. Admittedly the USN was still possibly a bit less skilled at carrier ops than the Japanese, but frankly, they were also a bit more honest about losses and real attrition rates. (The IJN actually declared Midway a victory in the Japanese press, and didn't admit their carrier losses to the Imperial General Staff for months. Leaving the army with the impression that the IJN strike force was still intact!)

Claims that the IJN entered the Indian Ocean operations with the equivalent full start of war numbers (despite all the casualties from Pearly Harbour to Darwin); and came away with only 5 losses from the entire operation: seem extremely unlikely.

I am sure many people can quote endless variations to these numbers (and I am happy to get suggestions of better sources), but let's just accept that on active operations you suffer steady attrition through combat and accident. And, perhaps more significantly, also accept that replacement pilots are often less experienced.

Consider the real Midway

In real life 1942, the USN would almost certainly have lost had the Japanese not been so reduced by attrition and distracted by other operations. Even at the real Midway, Yamamoto made a mistake in not keeping the main body advancing. He probably still would have won. The USN had practically nothing left to face his force, and the Wikipedia article (referenced 30.4.21) on Midway makes the following point:

Historian Samuel E. Morison noted in 1949 that Spruance was subjected to much criticism for not pursuing the retreating Japanese, thus allowing their surface fleet to escape.[156] Clay Blair argued in 1975 that had Spruance pressed on, he would have been unable to launch his aircraft after nightfall, and his cruisers would have been overwhelmed by Yamamoto's powerful surface units, including Yamato.[154] Furthermore, the American air groups had suffered considerable losses, including most of their torpedo bombers. This made it unlikely that they would be effective in an airstrike against the Japanese battleships, even if they had managed to catch them during the daytime.[157] Also, by this time Spruance's destroyers were critically low on fuel.[158][159]

As an aside: Consider the effects of allies actually cooperating.

It is also worth noting that the allies had genuinely tried to run interference for each other for months. When Churchill heard the Indian Ocean Raid was coming, he asked Roosevelt for a diversion in the Pacific, and was told the Doolittle raid would be hastened. It was too late to effect the actual Indian Ocean Raid, but it certainly convinced the Japanese they couldn't take the time to have another go at finishing off the Eastern Fleet before turning back to face the USN. The IJN had failed at their only chance of avoiding a two front war, and would have to keep major forces bouncing back and forth between the Truk/Rabaul and Singapore bases for most of the war to try and deal with this failure.

Likewise, when Midway was coming, Roosevelt requested the British Eastern Fleet try a diversion in the Indian Ocean. 

The RN had just invaded Madagascar (May 5), to prevent the expected Vichy follow through to the handover to Japan of Indo-China, with the handover to Japan of Madagascar. (Which would have almost certainly cut British supplies to the Middle East, and Allied supplies to Russia via Iran, and possibly have meant a combined German and Japanese Atlantic/Indian Ocean attack on merchant shipping might have won the war for them in a single move...)

Japan hadn't actually been planning to occupy Madagascar, but nonetheless responded with a redeployment of naval forces – particularly submarines. (They actually managed to torpedo one of the Revenge class battleships off Madagascar – the tenth allied battleship sunk or put into dry dock by the IJN in 6 months – but she sailed to South Africa under her own steam and was quickly repaired.)

When Midway was happening Admiral Somerville tried another diversionary attack against the Andaman Islands, threatening the Burmese coast. Again, simply too late to effect Midway, but again, considering the Burma campaign was still in full swing, drawing the Japanese attention in two directions, rather than being able to focus on one. Similar efforts later in the war meant that Eastern Fleet (sometimes supported by the USS Saratoga) attacks on the oil fields in the East Indies were more or less co-ordinated with USN offensive operations in the Pacific.

[And later, after the USN was reduced to one operational carrier at Santa Cruz, the RN loaned an armoured carrier to assist. See Wikipedia article on HMS Victorious' service with the USN (referenced 30.4.21) USS Hornet was sunk and USS Enterprise was badly damaged at the Battle of the Santa Cruz Islands, leaving the United States Navy with only one fleet carrier, USS Saratoga, operational in the Pacific. In late December 1942, Victorious was loaned to the US Navy after an American plea for carrier reinforcement.[6] ... Rear Admiral DeWitt Ramsey, commanding the division, carried out evaluation exercises and patrol sweeps in June and determined that Victorious had superior fighter control but handled Avenger aircraft poorly because of their weight. Accordingly, he transferred 832 Squadron FAA on to the Saratoga and US Carrier Air Group 3 on to the Victorious. Thereafter, Victorious's primary role was fighter cover and Saratoga mainly handled strikes. ... On 27 June, TF14 was redesignated Task Group 36.3 and sailed to provide cover for the invasion of New Georgia (part of Operation Cartwheel). Victorious spent the next 28 days continuously in combat operations at sea, ... launching 614 sorties. Returning to Nouméa on 25 July, Victorious was recalled home. ... Though the Japanese had four carriers to Ramsey's two, it seemed clear that they were not intending to press their advantage and the first two carriers of the new Essex-class had arrived at Pearl Harbor well ahead of schedule... Again, and despite most history books ignoring or misinterpreting it, the allies genuinely tried to work as allies.]

Any good tactical guide from Sun Tzu onwards will note that keeping your enemy unbalanced with flurries of light jabs, often has a significant effect on the development of the total fight: and it is usually when they are unbalanced that you get to deliver the actual knockout blows.

Consider a Midway without allied assistance or at least distraction

Now imagine the same battle being fought in February, March or April, with all 6 or the IJN's main carriers still operational at a bit closer to peak strength, and the USN much less prepared. Frankly it wouldn't have mattered if it was fought off Midway, or off Hawaii itself... (though if Midway or even Hawaii had fallen in December 1941, it may have been fought off San Francisco instead...)

Most importantly, the actual USN success at Midway was based on 7 distinct 'lucky breaks', that all needed to happen for success...

 A) partially breaking Japanese codes; B) having the time to work out the 'water shortage' ruse to confirm the information; and C) having the time to reinforce both Midway and the Pacific Fleet - particularly with enough new aircraft to make the defences at least competitive; and D) combat experience from Coral Sea that meant Yorktown – but still only Yorktown – had the capability of launching a full strike effectively. 

Even then it was pure luck kicked that a combination of E) the vital Japanese scout plane failing in its job; F) the slaughter of the USN's torpedo bombers allowing a crucial brief gap in Japanese fighter cover; and G) a small force of 18 dive bombers that had actually got lost, and was almost out of fuel, but took the risk to follow an errant destroyer just long enough to attack at a critical moment...) 

Had any one of those 7 critical factors not gone the USN's way, they would probably have lost at Midway.

Had Yamamoto pushed on with his main force, they would probably still have lost at Midway.

It is worth quoting the Wikipedia commentary on Midway (referenced 30.4.2021) in some detail to reinforce the 'luck' point, and to emphasise the fact that even after 6 months of war, the USN was terribly inexperienced in carrier ops.

Fletcher, along with Yorktown's commanding officer, Captain Elliott Buckmaster, and their staffs, had acquired the first-hand experience needed in organizing and launching a full strike against an enemy force in the Coral Sea, but there was no time to pass these lessons on to Enterprise and Hornet which were tasked with launching the first strike.[95] Spruance ordered the striking aircraft to proceed to target immediately, rather than waste time waiting for the strike force to assemble, since neutralizing enemy carriers was the key to the survival of his own task force.[94][95]

While the Japanese were able to launch 108 aircraft in just seven minutes, it took Enterprise and Hornet over an hour to launch 117.[96] Spruance judged that the need to throw something at the enemy as soon as possible was greater than the need to coordinate the attack by aircraft of different types and speeds (fighters, bombers, and torpedo bombers). Accordingly, American squadrons were launched piecemeal and proceeded to the target in several different groups. It was accepted that the lack of coordination would diminish the impact of the American attacks and increase their casualties, but Spruance calculated that this was worthwhile, since keeping the Japanese under aerial attack impaired their ability to launch a counterstrike (Japanese tactics preferred fully constituted attacks), and he gambled that he would find Nagumo with his flight decks at their most vulnerable.[94][95]

American carrier aircraft had difficulty locating the target, despite the positions they had been given. The strike from Hornet, led by Commander Stanhope C. Ring, followed an incorrect heading of 265 degrees rather than the 240 degrees indicated by the contact report. As a result, Air Group Eight's dive bombers missed the Japanese carriers.[97] Torpedo Squadron 8 (VT-8, from Hornet), led by Lieutenant Commander John C. Waldron, broke formation from Ring and followed the correct heading. The 10 F4Fs from Hornet ran out of fuel and had to ditch.[98]

Waldron's squadron sighted the enemy carriers and began attacking at 09:20, followed at 09:40[99] by VF-6 from Enterprise, whose Wildcat fighter escorts lost contact, ran low on fuel, and had to turn back.[98] Without fighter escort, all 15 TBD Devastators of VT-8 were shot down without being able to inflict any damage. Ensign George H. Gay, Jr. was the only survivor of the 30 aircrew of VT-8. He completed his torpedo attack on the aircraft carrier Sōryū before he was shot down, but Sōryū evaded his torpedo.[100] Meanwhile, VT-6, led by LCDR Eugene E. Lindsey lost nine of its 14 Devastators (one ditched later), and 10 of 12 Devastators from Yorktown's VT-3 (who attacked at 10:10) were shot down with no hits to show for their effort, thanks in part to the abysmal performance of their unimproved Mark 13 torpedoes.[101] Midway was the last time the TBD Devastator was used in combat.[102]

The Japanese combat air patrol, flying Mitsubishi A6M2 Zeros,[103] made short work of the unescorted, slow, under-armed TBDs. A few TBDs managed to get within a few ship-lengths range of their targets before dropping their torpedoes—close enough to be able to strafe the enemy ships and force the Japanese carriers to make sharp evasive maneuvers—but all of their torpedoes either missed or failed to explode.[104] Remarkably, senior Navy and Bureau of Ordnance officers never questioned why half a dozen torpedoes, released so close to the Japanese carriers, produced no results.[105] The performance of American torpedoes in the early months of the war was scandalous, as shot after shot missed by running directly under the target (deeper than intended), prematurely exploded, or hit targets (sometimes with an audible clang) and failed to explode at all.[106][107]

Despite their failure to score any hits, the American torpedo attacks achieved three important results. First, they kept the Japanese carriers off balance and unable to prepare and launch their own counterstrike. Second, the poor control of the Japanese combat air patrol (CAP) meant they were out of position for subsequent attacks. Third, many of the Zeros ran low on ammunition and fuel.[108] The appearance of a third torpedo plane attack from the southeast by VT-3 from Yorktown, led by LCDR Lance Edward Massey at 10:00 very quickly drew the majority of the Japanese CAP to the southeast quadrant of the fleet.[109] Better discipline and the employment of a greater number of Zeroes for the CAP might have enabled Nagumo to prevent (or at least mitigate) the damage caused by the coming American attacks.[110]

By chance, at the same time VT-3 was sighted by the Japanese, three squadrons of SBDs from Enterprise and Yorktown were approaching from the southwest and northeast. The Yorktown squadron (VB-3) had flown just behind VT-3, but elected to attack from a different course. The two squadrons from Enterprise (VB-6 and VS-6) were running low on fuel because of the time spent looking for the enemy. Air Group Commander C. Wade McClusky, Jr. decided to continue the search, and by good fortune spotted the wake of the Japanese destroyer Arashi, steaming at full speed to rejoin Nagumo's carriers after having unsuccessfully depth-charged U.S. submarine Nautilus, which had unsuccessfully attacked the battleship Kirishima.[111] Some bombers were lost from fuel exhaustion before the attack commenced.[112]

McClusky's decision to continue the search and his judgment, in the opinion of Admiral Chester Nimitz, "decided the fate of our carrier task force and our forces at Midway ..."[113] 

Now personally, I feel that Midway was one of the greatest naval victories of all time. But I feel that particularly strongly because it is impressive how many pieces of pure luck came together to allow an inferior and vastly less experienced force to win. Operating mainly withe obsolete equipment and tactics, and losing as many aircraft to getting lost and running out of fuel as to enemy action, the USN none the less managed to fluke a victory. And if those 18 lost dive bombers had not turned up at precisely the right moment, that would simply not have happened.

Luck is always important in battle. In this particular case, even with all the other 6 vital factors accidentally coming together, it was this 7th, a lucky late arrival from the wrong direction by lost planes... that actually won the battle.

Midway fought same time, but no allies

Had Japanese been able to concentrate on this operation, without the distractions of armies and air fleets and naval support fighting simultaneously in Burma and New Guinea and other places. It is hard to see how they could have failed to win.

For a start, even if Coral Sea had sort of happened; and even if the Japanese had only sent 2 carriers to Coral Sea instead of the 5 they used for the Indian Ocean Raid (which might have meant Coral Sea became a decisive loss for the USN, with Yorktown being sunk as well – and thus being unavailable for Midway – even if the USN did still manage to take out Shoho); and even if Shokaku and Zuikaku missed Midway as a result of aircraft attrition: the IJN just would have had way more resources to throw at this operation.

But more importantly, even if the first 3 Japanese carrier losses still amazingly happened at this version of Midway, WITHOUT the threat of the Eastern Fleet in active operations attacking Madagascar and moving on the Andamans and the Burmese coast to consider: Yamamoto would have had much more incentive to simply keep advancing his main body for a killing blow.

It was the reality of still facing an active two front war that, more than anything else, that made Yamamoto reluctant to commit to the Kantai-Kessen (final battle) strategy right then and there.

Midway fought at the time of Coral Sea, but no allies

Not good. All 6 major Japanese carriers – with much less aircraft attrition over previous months – supported by the entire Japanese battle fleet: against the 3 or 4 available US carriers - still with no battle experience between them - and a few cruisers (actually less cruisers without the Australian ones present). At the real Midway many of the American flight crews were hopelessly untrained, and Fletcher was very grateful for Yorktown's limited battle experience. According to some of the pilots, many of the Devastator pilots had never taken off a carrier with a torpedo attached before. 

At the real Midway 18 US aircraft fluked a breakthrough to hit 3 carriers, and won the battle. Even if the same thing accidentally happened in this case, the 3 surviving Japanese carriers would still have been more than capable of smashing the slaughtered US air groups and potentially all 3 or 4 US carriers, even before the IJN's main body arrived to chase any survivors from the field. 

Knocking out 3 carriers with just 18 aircraft was an amazing fluke by such an inexperienced and poorly equipped force. (No working torpedoes for God's sake! The only functional role of the Devastators at this battle was as sacrificial decoys! Unsurprisingly, Midway was the last time the Devastator was used in carrier combat...)

Knocking out 6 closer to full strength IJN carriers with these resources and tactics? Not likely.

It gets even worse if the night combat trained Japanese surface fleet gets anywhere near the largely daylight operations only US ships.

Midway fought at the time of the Indian Ocean Raid, but no allies

A more interesting comparison.

Let's say the 5 IJN carriers from the Indian Ocean Operation against the 3 the USN had available just then. (Which assumes Kaga had still been withdrawn for repairs and upgrades... which is much less likely in this case.)

Actually this is possibly the best chance the USN might have had out of these scenarios. 

Admittedly they still didn't have the option of the radar guided night strikes that Admiral Somerville was counting on to balance his inferior numbers, if he could get an engagement in the Indian Ocean: but they would at least have all received Wildcat's instead of Buffalo's, and had a few months of operational experience. 

All right, Coral Sea (and even real Midway) showed the USN were still far behind the IJN in launching good strikes. But the success of the 9 land based Blenheim bombers from Ceylon to get past the IJN CAP in the Indian Ocean and straddle Akagi with bombs, showed that catching the IJN off guard was possible even without sacrificing dozens of Devastator crews in Kamikaze runs. Not learning from the experience of that shocking vulnerability, or at least not being able to find an effective solution to it, is actually the main reason that the IJN lost so many battles for the rest of the war.

I still think that the IJN's superior resources would make this battle very hard for the USN to win. But never underestimate the incompetence of Nagumo in his ability to snatch defeat – or at least inadequate results for the efforts outlayed – from the jaws of victory.

[But frankly even Somerville's risk – and risk it was – of attempting a night ambush with radar planes against the 2 carriers he thought were coming, was a gamble. Even the much greater RN combat experience with radar guided CAP's and fighting off waves of hundreds of German and Italian bombers in the Mediterranean, very probably wasn't enough to overcome 5 still efficient IJN carriers in daylight. A night attack was their only real chance. The idea that even 3 of the USN's still combat inexperienced carriers could do better in daylight is not convincing, particularly as they had no functional torpedo's! And if they did fluke knocking out 3 carriers at similar cost to their own aircraft as at the real Midway, the other two or three IJN carriers – backed by the main force with it's extra support carrier (or two or three extra support carriers if the Aleutians distraction had been dismissed) – were still almost certainly going to win.]

Midway fought at the time of Darwin, but no allies

Even if you believe that the Japanese only lost 5 aircraft on the Indian Ocean Raid, you have to accept that the 4 carriers the attacked Darwin had far bigger and more efficient aircraft loads before taking 34 losses/serious damages at Darwin. The same force would have had more than double the carriers, planes, and chance of winning: as at Coral Sea.

Midway fought at the time of Battle of Java Sea

Frankly I only mention it to point out that the IJN mounted several substantial attacks, and won several major sea battles, while the USN was still frantically trying to recover from Pearl Harbour. Consider the same efforts concentrated on preventing that recovery.

Midway fought at the time of Pearl Harbour, but no allies

If Japan wasn't trying to attack everywhere at once, and could concentrate the forces allocated against the British, Thais, Burmese and Dutch against the US, why not follow through? Even Nagumo would have been willing to take a third strike against Pearl in these circumstances. Particularly with his boss Yamamoto and his main body following close behind, and carrying the 3 crack divisions no longer needed to invade for Malaya for an invasion of Hawaii! (See Japanese discussions of just such an invasion here.)

It is hard to imagine the American carriers not trying to intervene? (Though it would probably be more sensible for them to run for the US West coast instead.) 

[Saratoga was actually entering San Diego harbour when the attack started, while Lexington was near Midway and Enterprise had just sent 18 of her Dauntless's to Pearl that morning - and had most of them shot down either by a combination of the Japanese fighters and US AA!]

But even had the two carriers actually available been able to link up and co-ordinate somewhat, they could hardly be in organised position to strike back much before the main body arrived. It is also worth noting that Lexington for instance was still equipped with just 17 Buffalo fighters at this stage! Buffalo's!!! The USN, unlike the RN or IJN, could still only really fight in daylight. (It certainly lacked the radar guided bombers the RN has to make air attacks at night possible.) 

Both US carriers together, fielding less than 40 fighters, against 147 Zero's... in daylight... And their Devastator torpedo bombers lacked a functional torpedo! It would be entirely down to  perhaps a couple of dozen Dauntless dive bombers against 7 Japanese carriers and probably 7 battleships and God knows how many cruisers, destroyers and submarines as well.

In reality we get this (Wikipedia article on Enterprise sourced 30.4.2021):

Enterprise received radio messages from Pearl Harbor reporting that the base was under attack, and she was later directed to launch an airstrike based on an inaccurate report of a Japanese carrier southwest of her location. The strike was launched around 17:00, consisting of six Grumman F4F Wildcat fighters of Fighting Squadron Six (VF-6), 18 Douglas TBD Devastator torpedo bombers of Torpedo Squadron Six (VT-6), and six SBDs of VB-6.[12]

Six dive bombers against 6 Japanese carriers! The Devastators without functional torpedos are mere distractions. Even had Lexington rendezvoused next day for a joint strike, her 58 total bombers and torpedo bombers also come down to less than 20 extra dive bombers. The two of them together against practically the entire Japanese navy?

It is very hard to see any combination of fantastic flukes that might make this a winning proposition for the USN.

Frankly it doesn't bear thinking about.

Some possible USN reinforcements?

To be fair, if Britain and France had not gone to war against Germany, and there was no Atlantic Ocean battle going on, then the USN would have had marginally more resources available to face the Japanese. The 'Neutrality Patrol' in particular would have been a little less important, and the US could have relied on what Kissinger referred to as the 'sure shield' of the RN to denude East Coast defences even further. 

Battleship Reinforcements?

In reality that would probably only amount to another 2 or 3 of the oldest and most vulnerable USN battleships - say Arkansas, New York and Texas. I am sure they would have made nice additional targets at Pearl Harbour.

There is the outside chance that the brand new North Carolina or Washington might have been working up in the Pacific rather than the Atlantic. In reality of course, Washington was still in trials in the Atlantic, and still having propellor trouble and failing to reach designed speeds. But in the extremely unlikely event that the North Carolina's trials been done in the Pacific instead of the Caribbean, is it possible she might have added actual value? 

North Carolina's new 20 x 5" heavy AA battery alone would have almost doubled the heavy AA firepower of Battleships Row... If it could be manned and used effectively. (Her extra 16 of the dreadful 1.1" AA, and 18 .50 Cal machine-guns would be considerably less significant.) But even if she was there, she would still be only starting her work up, and as such would probably be trapped in one of the inside positions on Battleship Row. Limited arc AA from there was much harder, even if the crews were actually available, experienced enough to cope with limited arcs, and competent? Frankly a relatively untrained crew might be just as likely to hit any adjacent battleships as Japanese bombers... 

But what about North Carolina surviving in Battleship Row?

Ryan Szimanski does a very entertaining Youtube analysis of whether damage to ships sunk at Pearl Harbour would have sunk an Iowa, which suggests North Carolina would probably have survived those first two strikes, even if damaged. (Though note the case where he says 'that would probably have sunk an Iowa too'...) But presumably any of those battleships survive only if the Japanese don't get in a third or fourth strike... Which they definitely would under this scenario. Still, an amusing reflection.

Aircraft Carrier Reinforcements?

More significant would bc the location of the USN's other carriers: USS Yorktown, USS Hornet, USS Wasp and USS Ranger. 

Hornet had only been in commission for a little over a month, and was still doing basic training out of her port of construction Norfolk. She didn't head off for operational duties until March 1942, so I think we can safely assume she could not have been at Pearl Harbour in December 1941, or indeed available at the time of battles like Darwin, Java Sea, or Rabual. Her first actual appearance was the Doolittle raid, contemporary with Coral Sea, and hopefully I have pretty well covered her likely value from there on. She simply could not have been available at Pearl Harbour.

Wikipedia notes:   Yorktown was at port in Norfolk during the attack on Pearl Harbor, having just completed a patrol of the Atlantic Ocean. 

If Yorktown had been Pacific based instead of Atlantic at this time, her being in port after a patrol would imply either in Port on the US West Coast – no real difference – or, much worse, in port at Pearl Harbour! 

One of the saving graces of Pearl Harbour, and one of the great disappointments to the Japanese, was that there were no carriers in port. If there were, then the Japanese strike force would have prioritised them. Doesn't sound good for Yorktown, or the USN.

I suppose we could argue that she might have also been off doing a delivery to some US island base... but even that remote possibility would have put her in no better position for a counter-attack than Lexington or Enterprise. It might have potentially offered 3 carriers to counter-attack, and lifted the total number of Dauntless's available to almost half those available at real Midway. Giving a better possibility of doing similar fluke and damaging 3 of the 6 Japanese carriers, but it is still hard to see any possible fluke taking out all 6? 

Frankly I suspect if Yorktown had been wandering around with the other two, it might have encouraged them to try something silly. Particularly if third and fourth waves were coming in. But that implies that Yamamato's main body and his invasion fleet are also closing in...

Perhaps it would have been better for the USN, if such an incredibly unlikely set of chances didn't put Yorktown in any of these positions?

The only other aircraft carrier reinforcement possible in December 1941 was the undersized and extremely vulnerable USS Wasp. 

[Still armed with Vindicator dive bombers, the USN's first experiment with monoplane bombers. Wikipedia comments: Airmen with experience in more modern aircraft spoke disparagingly of SB2Us as "vibrators" or "wind indicators" in their later combat assignments.[11][12]  The RN inherited 50 from a French navy order, and tried to upgrade them adequately to fit them for escort carriers, but found them so unsuitable for operations that it was decided to re-equip those squadrons with the similar vintage but far more reliable Swordfish biplanes...]

As Wasp's Wikipedia article (referenced 9.5.2021) notes:

The Navy sought to squeeze a large air group onto a ship with nearly 25% less displacement than the Yorktown-class. To save weight and space, Wasp was constructed with low-power propulsion machinery (compare Wasp's 75,000 shp (56,000 kW) machinery with Yorktown's 120,000 shp (89,000 kW), the Essex-class's 150,000 shp (110,000 kW), and the Independence-class's 100,000 shp (75,000 kW)).

Additionally, Wasp was launched with almost no armor, modest speed, and more significantly, no protection from torpedoes. Absence of side protection of the boilers and internal aviation fuel stores "doomed her to a blazing demise". These were inherent design flaws that were recognized when constructed, but could not be remedied within the allowed tonnage.[4] These flaws, combined with a relative lack of damage control experience in the early days of the war, proved fatal.[5]

Wasp's limited capacity meant that she was held back for Atlantic operations (where her most useful operations in first 6 months of 1942 were ferrying fighters to Malta), until the USN was reduced to desperate straits and forced to use her as a frontline carrier. After the losses at Coral Sea and Midway, they had no choice. Wasp arrived off Guadalcanal in August 1942, and was – perhaps fortunately – off re-fuelling during the Battle of Eastern Solomons. But she was torpedoed and sunk anyway within a few weeks.

The possibility of the Wasp, with her  Vindicator dive bombers (predecessor to the excellent Dauntless, but just as bad as the Devastator's or Buffalo's), making much difference against the IJN in the earlier battle options above is somewhat dubious, but must at least be taken into account... Post Midway she received Dauntless's, but by then she had repeated engine problems, and struggled to make 25 knots for some of the critical mid period (sometimes only managing 15), but an operational flight deck is a flight deck, and if she was way less protected than most USN vessels, she was still no more vulnerable than many of the IJN's ships. 

Which leaves USS Ranger – a far too light experimental carrier – which the USN never considered fast enough or in any way suitable for Pacific Operations. She spent her entire operational life in the Atlantic on escort or ferry roles, and wasn't even considered worth upgrading to carry the more modern and heavier aircraft until the war was almost over. 

As Ranger's Wikipedia article notes: On 15 April 1942, Prime Minister Winston Churchill cabled President Franklin Delano Roosevelt requesting North Carolina and Ranger reinforce the Eastern Fleet in the wake of the Indian Ocean Raid...  Admiral Ernest King had already definitely stated that Ranger and any other major fleet unit could not be made available for the Indian Ocean... King's draft response to Churchill's insistence displayed a lack of tact. Roosevelt supported King, but toned down King's draft by playing up Ranger's faults to steer the British towards accepting the ferry mission.[42]

I think it is fairly safe to dismiss the idea that the USN would have accepted the idea of having no carriers at all in the Atlantic in 1941, and suggest that Ranger and Wasp would almost certainly have been there in December 1941 even if Hornet had been relocated to the Pacific.

A possibility of an extra few cruisers or destroyers being available in December 1941 if there was no neutrality patrol is also there: but again, the numbers would not be particularly significant.

Other possible factors to consider?

More interesting is the question of whether continued increases in orders for aircraft by the RAF and the French Air Force between 1939 and 1941 might have boosted aircraft types and numbers available to US forces? 

Presumably most such aircraft would be going to fill said orders, but under peacetime conditions, there may have been more flex in deliveries than otherwise? It is hard to imagine the numbers would be enough to make substantial differences, but certainly there might be some variations? But also consider how US industry had benefited from the war starting in 1939.

A considerable part of US armaments expansion pre 1941 was to fill British or allied orders, and included everything from light infantry weapons and ammunition; to Grant and Sherman tanks; to Warhawk, and Wildcat fighters (and of course the Mustang fighter, which was designed for a British order); to Liberators and Catalina's; to Liberty ships and Escort Carriers. Even destroyer and escort production had begun to increase in response to the Battle of the Atlantic at a rate well beyond what the USN would have been doing otherwise. Without those orders, the US would have had only a fraction of the armaments production capacity it benefited from in December 1941.

In practice the US would have been in a far worse military position to deal with and replace the sort of casualties it took in late 1941 and early 1942 if a major war hadn't already been going for a couple of years.

Weird Possibilities?

If war had not started in 1939, then it is hard to see the Japanese daring to attack a potential coalition of Britain, France, the Netherlands, the US, and perhaps even Italy in December 1941. 

No matter what the Germans think or do.

If the Japanese are willing to go to war in December 1941, or perhaps earlier in June or July in a better planned cooperation with the Germans: it would most likely be only against the Russians. (Perhaps particularly if Italy is also attacking Russia, and teh British and French are showing further disinterest?)

In which case it is theoretically possible to see the US still putting enough pressure on Japan in support of China to make Japan want to attack the US. Theoretically.

In fact I suppose if Japan hadn't gone to war on Russia, they might even be in a better position to attack the US, if they kept trying to support China even without British and French assistance and access other Burma supply route etc...

But either way, if Japan attacks the US when the US has no Britain, France, Netherlands or Australian allies to distract them, then it is almost impossible to see how the US would not have suffered even worse losses than it already did.

Even if the British and French could be relied on to step in to help the US when it was attacked, they would not have been ready to launch any effective offensive operations until months after the Japanese had completed the occupation of Hawaii and the Philippines, and the destruction of much more of the USN. (Leaving the RN the challenging task of fighting past the Japanese occupied positions in the Philippines and Taiwan and China before it could bring any pressure to bear on Japan itself. A huge task that the US took 3 years to gather the resources to do even when it had major allies... And that is only if Britain could be convinced to consider the cost worthwhile while Germany and Italy are still sitting there as potential threats, possibly looking for new opportunities as Russia collapses?  And even if Britain did intervene, would France or the Netherlands want to play too?)

It is perhaps amusing to consider a world war of Germany and Japan (and perhaps Italy – land and air anyway as the RN would continue to ensure that the Italian Navy would not take risks trying to attack US interests), against a coalition of the Russians, Chinese and US. 

Perhaps internal politics might have led Britain and France and the other allies to act like the Americans actually did, and just stand aside for years and try and profit from other people's misfortunes. without doing anything to actually assist in maintaining some sort of order?

But if any of these myriad options did happen, in any form, it is very hard to see it ending well for the USN.

The US would no doubt have eventually recovered, even from the loss of their entire Pacific fleet, and the resulting carrier launched bombing of their West Coast cities and factories. No doubt they would possibly have eventually defeated Japan, but presumably having taken the sort of economic damage that Britain actually experienced through having to take most of the load for many years with little support. (Which would have re-entrenched the British as the dominant international power post war, not the Americans... Interesting... the Middle East would certainly have been more peaceful since... probably Asia too... But Eastern Europe might have been an ongoing bloodbath...)

But the US had no more chance of saving their allies in Soviet Russia and China in such circumstances than the British did of saving Poland and Yugoslavia. (Would the rump of China have still finished Communist? Probably. The US allied with the two Communist powers, or at least what is left of them? Fun concept.)

So no doubt a peace would have eventually have happened, probably with US West Coast cities, and almost all Japanese cities, being in the same ruins as the US East Coast cities were at the end of their disastrous intervention in the Napoleonic wars. (See the War of 1812... The reality version, where the US war aims to 'liberate' Canada fail; the US coastal cities and trade are in ruins; and the inevitable peace allows the British to go back to their actual priority of finishing off Napoleon. Not the US apologists version where the US 'won' something in some way... see Canadian opinion of that fantasy.)

But Germany would still dominate European Russia, and although the peace might involve Japan ceding back the Philippines and much of China so the US could claim victory, Japan would probably still have been left with much of Siberia and Mongolia and Korea etc. (And quite as capable of economic recovery post war as the US was after the War of 1812...) 

Even an unlikely, and very costly, US invasion of Japan would not have changed Germany dominating Russia. Without the British Empire and Commonwealth to carry much of the effort, the US simply wasn't capable of winning more than one front at a time. And her economy would have looked like Britain's post war, while Britain's would probably have looked more like America's.

But that is far more conjectural than assessable.

Conclusion – very bad news for USN

In fact, returning to more practical realities, without British and Australian and Netherlands allies, the chances of the USN coming out on top of the IJN in early 1942 are almost impossible to imagine.