Alternatives to Pearl Harbour?

Were there any other plans made for surprise attacks on the USN preceding the invasion of Southeast Asia?

Alternatively, were there any strategic/tactical decisions which would have wrought more destruction than OTL Pearl Harbour?
 
Originally the plan was to just attack the Philippines and let the US Pacific fleet come to it's defense upon which Japan would defeat them in a "grand decisive battle" like Tsushima. Pearl was already stretching the limits of what they could accomplish and really the only way for them to have done better at the outset would have been for them to launch a third strike to destroy the oil farms and drydock there.
 

Saphroneth

Banned
Originally the plan was to just attack the Philippines and let the US Pacific fleet come to it's defense upon which Japan would defeat them in a "grand decisive battle" like Tsushima. Pearl was already stretching the limits of what they could accomplish and really the only way for them to have done better at the outset would have been for them to launch a third strike to destroy the oil farms and drydock there.

Mostly right; nope on the third strike.
For a number of reasons.
First - the oil farms and drydock were very durable. (The dry dock may not actually be possible to cripple with carrier aircraft air-launched weapons.)
Second - this third strike would have to be launched so late the landing-on would have taken place at night. Good way to lose pilots and planes.
Third - the defences were ready and waiting. Even the second strike took heavy casualties, considering, and by this third strike (which would be several hours later), alerted defences would chew them up. They'd lose a large fraction of the CAGs for little further gain.
Fourth - they were running critically low on fuel for the DDs. A few more hours might mean they'd actually have to abandon some for lack of fuel.
And fifth - to the commander on the spot, he's scored a great victory. Done everything that was needed and more. If he stays around, the enemy carriers might get him. Enemy land air might get him. Enemy subs might get him. He's risking THE Kido Butai, the greatest weapon Japan has... to attack some fuel tanks? When the Americans will surely surrender anyway?
War is fought by human beings. In this case, the human being that was Admiral Nagumo made the right choice.
 
Catching the USN carriers in harbour and sinking them would be about as good as it could get for the IJN.

Another possibility for more damage would be deliberatedly targeting personel quarters in the first wave to kill as much trained personel as possible. If the strike was just before morning call, a few dive bombers putting heavy HE bombs on barracks could inflict a lot of casualties, and it would be possible to identify the critical buildings to hit (pilots quarters, aircrew barracks, etc)
 

Saphroneth

Banned
Catching the USN carriers in harbour and sinking them would be about as good as it could get for the IJN.

Another possibility for more damage would be deliberatedly targeting personel quarters in the first wave to kill as much trained personel as possible. If the strike was just before morning call, a few dive bombers putting heavy HE bombs on barracks could inflict a lot of casualties, and it would be possible to identify the critical buildings to hit (pilots quarters, aircrew barracks, etc)

I think there's no single time when more than one or two CVs were in harbour. They were being worked heavily securing the defensive preps for the US overseas islands - if they're in harbour, it's because that job is finished! (In that case, the whole plan stubs its toe on Wake and Guam anyway.)
 

U.S David

Banned
The original plan was to attack the Philippines. That's what the American planners were expecting.


The Panama Canal would be a place I would attack. Send Submarines to blow it up, while bombing Pearl Harbor. This prevents ships in the Atlantic from coming for a while.
 
I think there's no single time when more than one or two CVs were in harbour. They were being worked heavily securing the defensive preps for the US overseas islands - if they're in harbour, it's because that job is finished! (In that case, the whole plan stubs its toe on Wake and Guam anyway.)

Even sinking just one would be better than OTL. Two would be even better.

But I think the real damage to be done would be on the personel. I'll have to look it up, but I dont't think there were heavy personel losses on shore.
If the USAAF and USN barracks arrangments were compact, and given the precision capability of IJN dive bombers, losses could have been much greater.
 

Saphroneth

Banned
Even sinking just one would be better than OTL. Two would be even better.

But I think the real damage to be done would be on the personel. I'll have to look it up, but I dont't think there were heavy personel losses on shore.
If the USAAF and USN barracks arrangments were compact, and given the precision capability of IJN dive bombers, losses could have been much greater.

Would it be possible to actually sink CVs without letting BBs survive? I doubt it. That or you let planes survive.
A theoretically perfect strike would of course do better than OTL. But that's tautological - you may as well say that a lost bomber from some random Wimpey squadron might blow up Hitler in early 1940.
The Pearl strike was already fantastically potent in exactly what they intended to do - destroy the US pacific fleet, ruin Pearl's quick power-projection capabilities by destroying a number of aircraft, and terrifying the US public.
They did. Just, they got the wrong response.
 
Regarding targeting personel, if the houses in the "wisteria lane" on the lower left side of this photo are the residence of the critical personel, they are hard targets because it would require a bomb in each house to target it's resident. But if the larger rectangular buildings on the right are barracks, a 250Kg HE bomb on each one before people leave them for battle stations would do a lot more damage than hitting an hangar. It's easier to build planes than to train people.

The L shaped building on the center is probably a Command/Administrative building and would probably be manned during an attack. It's another potential target.

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Another option would be for Japan to push south into the Dutch Indies, Malaya, and Indian Ocean while bypassing the Phillipines and any other US posessions...in essence daring an isolationist US to intervene in a war between Japan and Britain and the NEI.

Obviously they run the risk that the US will see this as a clear strategic threat to the US or a situation of "crossing the line", and here's a possible interesting outcomes to this:

1. To "send a message" the US very publically orders the bulk of the Pacific fleet to the Phillipines. I think that is pretty much a given regardless of whether or not the US declares war. Two interesing options then occur:

2. The US does not declare war and its fleet is not opposed by the Japanese. It becomes stationed in the Phillipines and other US bases are beefed up. The US has no causus belli against Japan that the Congress would consider sufficient justification for a DoW. Japan's actions are interpreted by isolationist Americans as part of an expanded "European War" and are intended to deny Britain access to resources from Australasia and perhaps India. In essence, rather than risking all on war with the US, they risk it all on the hope that such a war can be avoided...at least for the time being.

3. If the US declares war and moves fleet westward, the Japanse implement their planned attritional strategy. As the US fleet (8old dreadought battleships with limited AA capibility, 3 carriers with, and support vessels) steam across the Pacific, Japan's fast carrier force escorted by the fast Kongo battleships and destroyers (essentially the Pearl Harbor task force) strikes in mid pacific as part of the "attrition strategy" inherent in Japanese planning for the "decisive battle". The US fleet, with pre-war standard AA and generally inferior and outnumbered naval aviation, is mauled by the Japanese carrier strikes, losing 3-4 battleships and maybe 2 carriers which sink in the deep Pacific. Couple this with land based G3M and G4M air raids on the Phillipines to diminish the repair and resupply capability of US naval bases there, even if the Japanse lose a carrier or two they are in a better position than OTL to negotiate an end to the war. Or, if the US hasn't yet declared war but this seems only to be a matter of time, maybe do this as a "surprise attack" on the fleet while it is underway and perhaps even less prepared to mount a sucessful defense or counterstrike.

Another thing to consider. Even if Japan loses these early naval battles decisively things might turn out far better for them than in OTL. They would have lost the "decisive battle" early and militarist dogma would have been disproven. Liberal groups in Japan (there still were some in high places) might achieve a change in government allowing Japan to negotiate an end to the war without the mass bombings, allied occupation, and other elements of an unconditional surrender (an Allied doctrine that hadn't yet solidified in 1941-42). They'd be forced to give up all 1941-42 conquests, pay reparations, perhaps accept some treaty limitations on the size of Japan's military, and maybe even abandon the China war as well, but Japan might escape the loss of Korea, South Sakhalin, Formosa, and other earlier conquests, but it sure beats the alternative.
 
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Mostly right; nope on the third strike.
For a number of reasons.
First - the oil farms and drydock were very durable. (The dry dock may not actually be possible to cripple with carrier aircraft air-launched weapons.)
Second - this third strike would have to be launched so late the landing-on would have taken place at night. Good way to lose pilots and planes.
Third - the defences were ready and waiting. Even the second strike took heavy casualties, considering, and by this third strike (which would be several hours later), alerted defences would chew them up. They'd lose a large fraction of the CAGs for little further gain.
Fourth - they were running critically low on fuel for the DDs. A few more hours might mean they'd actually have to abandon some for lack of fuel.
And fifth - to the commander on the spot, he's scored a great victory. Done everything that was needed and more. If he stays around, the enemy carriers might get him. Enemy land air might get him. Enemy subs might get him. He's risking THE Kido Butai, the greatest weapon Japan has... to attack some fuel tanks? When the Americans will surely surrender anyway?
War is fought by human beings. In this case, the human being that was Admiral Nagumo made the right choice.


None of what you say is wrong if we take the battle in isolation - however it was a massive massive gamble / Risk to go to war with the United States in the first place and they should IMO have accepted the risk of losses sustained during a 3rd Strike.

I have not read anything that implies that the Japanese Navy imagined that total sucess would = anything more than a year to 18 month's grace to solidify their position in the Western / Central Pacific.

They knew that the US was massively expanding their armed forces and that it was only a matter of time before the Quantitive difference in forces would begin to tell.

I think that the best Japan could have hoped for would be for the US to have agreed to terms while the Japanese were in an advantageous position (and this only in the minds of the more freverent militant Japanese Leaders).

The more damage that they could achieve the better

In answer to the OPs question - I would have thought that a landing in force could have been attempted with the ultimate goal to have been to Hold the Island with an eye for future negotiations
 

Saphroneth

Banned
None of what you say is wrong if we take the battle in isolation - however it was a massive massive gamble / Risk to go to war with the United States in the first place and they should IMO have accepted the risk of losses sustained during a 3rd Strike.

I have not read anything that implies that the Japanese Navy imagined that total sucess would = anything more than a year to 18 month's grace to solidify their position in the Western / Central Pacific.

They knew that the US was massively expanding their armed forces and that it was only a matter of time before the Quantitive difference in forces would begin to tell.

I think that the best Japan could have hoped for would be for the US to have agreed to terms while the Japanese were in an advantageous position (and this only in the minds of the more freverent militant Japanese Leaders).

The more damage that they could achieve the better

In answer to the OPs question - I would have thought that a landing in force could have been attempted with the ultimate goal to have been to Hold the Island with an eye for future negotiations

Oh, gods no. You need to read up a lot on the state of the defences and how much damage they actually did, even surprised as OTL. Calbear knows more than I, but I know enough to say that the IJN had barely more hope of actually capturing Oahu than they did of capturing the moon.

Long story short - the AAA and the alerted fighter aircraft, diminished as they were, would have pretty much destroyed the CAGs of most of Kido Butai. Their main advantage - surprise - was gone, and Oahu was positively festooned with AA guns.
Here's a fact you may not know. OTL, the number of serviceable aircraft ready to go after the two deck load strikes on Pearl was enough for one more deck load strike, with only a small amount extra. All the rest of the aircraft were shot down, unrepairable, or needed repair time.
And most of those casualties were from the second strike, the one which had a little less surprise. If we assume the same casualty rates as the second wave took, then this third wave would leave the Kido Butai with about enough aircraft for three or four carriers to launch a strike - singular.
That's not the actions of a prudent Admiral, who knows he's missed the US carriers and that he might have to fight his way home.
 
Oh, gods no. You need to read up a lot on the state of the defences and how much damage they actually did, even surprised as OTL. Calbear knows more than I, but I know enough to say that the IJN had barely more hope of actually capturing Oahu than they did of capturing the moon.

Long story short - the AAA and the alerted fighter aircraft, diminished as they were, would have pretty much destroyed the CAGs of most of Kido Butai. Their main advantage - surprise - was gone, and Oahu was positively festooned with AA guns.
Here's a fact you may not know. OTL, the number of serviceable aircraft ready to go after the two deck load strikes on Pearl was enough for one more deck load strike, with only a small amount extra. All the rest of the aircraft were shot down, unrepairable, or needed repair time.
And most of those casualties were from the second strike, the one which had a little less surprise. If we assume the same casualty rates as the second wave took, then this third wave would leave the Kido Butai with about enough aircraft for three or four carriers to launch a strike - singular.
That's not the actions of a prudent Admiral, who knows he's missed the US carriers and that he might have to fight his way home.

They lost a grand total of 29 planes in the two strikes. They could've easily launched a 3rd attack on the instillation's and done serious damage.
 
Were there any other plans made for surprise attacks on the USN preceding the invasion of Southeast Asia?

Alternatively, were there any strategic/tactical decisions which would have wrought more destruction than OTL Pearl Harbour?

The Midway plan of 1942 adapted to 1941, ironically, might have done better. The USN thought the carriers main strength was supporting the southern drive, so an attack on Midway to lure out Kimmel's carrier strength beyond Oahu's support might have succeeded.
 
Here's a fact you may not know. OTL, the number of serviceable aircraft ready to go after the two deck load strikes on Pearl was enough for one more deck load strike, with only a small amount extra. All the rest of the aircraft were shot down, unrepairable, or needed repair time.

So, even if true, Nagumo still had roughly the amount of strength he threw at Darwin two months later (188 aircraft), which proved to be a devastating attack.

And most of those casualties were from the second strike, the one which had a little less surprise. If we assume the same casualty rates as the second wave took, then this third wave would leave the Kido Butai with about enough aircraft for three or four carriers to launch a strike - singular.

Assuming 20 aircraft lost in a third wave, that would be 49 overall with perhaps another 20 or 30 either damaged beyond repair or not repairable locally. 400-29-20-30 = around 320 aircraft for December 8th. Not seeing how Nagumo can't fight US carriers with 100 more aircraft than he had at Midway.
 
20 of the losses were from the 2nd wave. A further 74 aircraft were damaged, many total write offs.

Isn't that the combined total for the entire attack? Which is about 35 or so planes unable to fly afterwards for another attack per flight. Assuming the loss rate stays the same or even slightly worse Nagumo still has more aircraft then at Midway.
 
Isn't that the combined total for the entire attack? Which is about 35 or so planes unable to fly afterwards for another attack per flight. Assuming the loss rate stays the same or even slightly worse Nagumo still has more aircraft then at Midway.

The total for the whole attack was 29 shot down and about 121 damaged. Of the damaged total, many were only superficially damaged. Assuming 70 of the total had too much damage to be certified for flight again that day and 50 could fly, Nagumo "only" will have had 300 aircraft, or still 80 more than at Midway. Assuming NONE were able to fly again that day, Nagumo will still have had 250 aircraft immediately available, still more than at Midway.

So any way you slice it, there is little explanation for the lack of follow up attack beyond Nagumo's citiation of the unknown location of US carriers and land based bomber counter attack. Certainly Nagumo's punch was still very strong - better than what hit Darwin or Midway.
 
The total for the whole attack was 29 shot down and about 121 damaged. Of the damaged total, many were only superficially damaged. Assuming 70 of the total had too much damage to be certified for flight again that day and 50 could fly, Nagumo "only" will have had 330 aircraft, or still 100 more than at Midway.

So a third strike was entirely feasible and more importantly even if it only partially succeeded(not destroying the entire of the oil farms and/or only damaging the drydock) it could've damaged Pearl's ability as a functional harbor for awhile. Assuming they're at least able to destroy the drydock and damaged ship would be unable to have major repairs done at Pearl. That means if it isn't fixed by the time Midway rolls around then no Yorktown will be available.
 
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Were there any other plans made for surprise attacks on the USN preceding the invasion of Southeast Asia?

Alternatively, were there any strategic/tactical decisions which would have wrought more destruction than OTL Pearl Harbour?
Once the Pacific Fleet rebased in Pearl from San Diego at the start of 1941, Yamamoto expected to open the war with a surprise attack on it.

Prior to that, some "invade the Philippines, then nibble at the USN while it obligingly sails across the Pacific with submarines, land-based bombers, carrier strikes, and night actions with destroyers (with Long Lance torpedoes) before rolling over what's left with the mighty battleships of the IJN, then nip back home for tea and medals" was the gist of it.

The wikipedia article doesn't take too long to read for a taster.

Having said that, Dec 1941 was about the earliest that Japan could get the forces together to go to war - e.g. Zuikaku didn't commission until late September.
 
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