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]