America more alert December 7

[Derek Jackson]

I do NOT believe that FDR had specific intelligence of the plan to attack Pearl Harbor

I DO believe that there was intelligence of a likely Japanese attack which was not really properly acted on.

How much difference might it have made if more competent officers in the Pacific were told to be on the alert. I know that in OTL radar detected the Japanese aircraft but it was ignored or misinterpreted.

How credible is it given general but not specific warnings that:

a) Once the Japanese sneak attackers were detected that most land based planes would be scrambled and all the anti aircraft guns be ready.

b) American losses that Sunday morning are smaller and Japanese ones heavier.

c) The combination of Flying Fortresses and aircraft from the US Aircraft carriers do massive damage to the Japanese fleet.


If these things happened how much difference would that make to the course of the war, for instance in the Phillipines?

 

[JLCook]

Let's give Kimmel and Short 24 hours advance notice

That an attack. by naval aviation, is expected just after dawn on December 7, 1941! Perhaps the "atmospherics" are better or something, but word arrives in time!

For one thing, all of the P40s could be armed, and airborn instead of lined up wingtip to wingtip. If those aircraft are flying, great numbers of Japanese pilots will not be going home, whether the zero fighters are effective or not!

A lot of bomber and patrol aircraft can be searching North and Northwest of Oahu as well! In fact, the only thing to be found on those airbases SHOULD be fully manned anti-aircraft guns!

Not only would the battlelins NOT be anchored off Ford Island, the harbor would likely be empty. If I were Admiral Kimmel, I'd have sent the Battleships off to the West, say 150-200 miles out, where they'd be rendesvousing with the Carriers.

A Japanese air raid on an armed and empty Pearl Harbor (except for ships in drydock unable to leave, the harbor is empty) would still be likely to enrage AMericans, but the Japanese pilot losses would make the attack far more serious a problem for the IJN.

About the only drawback would be a continued American reliance on the Battleline for a longer period than they should!

 

[Valamyr]

I do NOT believe that FDR had specific intelligence of the plan to attack Pearl Harbor

Then any conclusions you will come up with will be flawed.

 

[Grimm Reaper]

It would have taken a pretty massive shakeup to get the US into shape on December 7, 1941. After all, a contingent of Japanese planes actually jumped the gun and were forced to circle Pearl Harbor for over 20 minutes IN BROAD DAYLIGHT without triggering an alarm.

 

[Romulus Augustulus]

Okay. So, let's say an airplane spots the Japanese readying for an attack and sends out an alert. US forces in air, AA ready and loaded. So, what next?

 

[Bill Cameron]

Then any conclusions you will come up with will be flawed.

Valamyr,

Touche!

BTW, how did your election monitoring stint in Florida go?


Bill

 

[BrianP]

If Pearl Harbor had 24 hours warning, then all other American Pacific bases would be alerted. Perhaps the Japanese would pick up the communication and call the attack off alltogether. They could then deny any intention of attacking.

If they do not intercept the message, and proceed, they would probably call a halt to the attack once they realize the element of surprise is gone. The attacks on the Philippines, Guam, Wake, etc. would probably be aborted. In this case, the United States would still declare war, but there would not be as much outrage as there was in OTL.

If the attack on Pearl Harbor was botched, would the Germans still declare war on the United States, and vice-versa?

 

[Derek Jackson]

If the attack on Pearl Harbor was botched, would the Germans still declare war on the United States, and vice-versa?

That is interesting and worrying

 

[Bill Cameron]

Derek,

The IJN left the Kuriles in late November for the Pearl Harbor operation. If any significant US preperations had been noticed between that time and the 7th, the attack would have most likely been called off.

I know it is now percieved wisdom that all the Nisei and other Japanese immigrants were good little farmers and storekeepers illegally interned and wrongly suspected of espionage and sabotage. That's what 50 years of good PR and a reparations bill will do for you.

The truth of the matter is that the Japanese did have an extensive spy network on both the West Coast and Hawaii and that the internment program took all of that away. They recieved constant updates about US forces on Oahu through their consulate there. You can take a short hike in the hills north of the harbor and easily watch anything happening in Pearl. Consulate officals would gather their information and cable it to the mainland where it would be passed back to Japan under diplomatic seal.

Japanese intelligence in this regard was so good that they weren't caught off guard by the USN carriers not being at Pearl. Instead they were caught off guard by the USN carriers returning to Pearl late.

Assuming that US preperations weren't extensive enough, or began too late, to call off the attack I think the results would be worse for both sides. Off the top of my pointy head, I'd figure:

- More pilot and plane losses for the IJN obviously.
- IJN ship losses would depend on the USN/USAAF finding the Japanese task force. Given the forces, doctrine, and training of that period this is something that isn't a certainty. Look at Midway for an example. If the USN carriers can launch a strike, there could be some damage but a carrier battle could begin with the US at long odds. (Throw the B-17s out of your equation. They did squat at Midway and low level 'skip' bombing hadn't been developed yet.)
- The USN battleline would not be a factor except in IJN planes losses due to AA fire. If the batteline sortied early enough to intercept the IJN strike force, the attack would have been called off. If the battleline sorties Saurday or Sunday, it won't be able to intercept but will also be an inviting target for IJN planes and submarines. (Don't forget those subs carrying the midgets)
- Having the USN batteline at sea does risk the irreversible loss of the warships comprising it. The US was able to raise and repair all but two ships 'lost' at Pearl. Having the battleline at sea means that won't be an option.
- If the USN batteline is at sea and the IJN planes don't quickly spot it, then Pearl gets pounded. This was the IJN's big mistake in the OTL. They sank ships and left intact everything the US needed to repair them. Making matters wose, they left intact everything Pearl needed to remain as an operational fleet base; fuel, ammo, etc. Without ships to target all that infrastructure gets hit. Just how badly depends on just how well the USAAF and AA batteries fight

Giving each side equal breaks, I'd guess moderate to heavy plane losses on both sides, damage to one or more IJN carriers, damage to one or more USN carriers, the loss of a BB or CA from the US batteline (subs), and a badly damaged Pearl Harbor infrastructure. That last part is the telling bit, Pearl may be damaged enough to force the US to base portions of the fleet back to the West Coast until the damage can be repaired.


Bill

 

[Bill Cameron]

If Pearl Harbor had 24 hours warning, then all other American Pacific bases would be alerted.

Brian,

In the OTL, MacArthur in the Phillipines did have that warning and his airforce was still caught on the ground by the Japanese strike from Formosa.

There was an extremely complacent mindset at work amongst the Americans at this time. It would have taken quite a shock to shake them out of their rut. And it did take quite a shock!

If the attack on Pearl Harbor was botched, would the Germans still declare war on the United States, and vice-versa?

I'd say yes. Hitler was enough of a fruitcake to do it anyway. Either he'd do it or another Reuben James in the Atlantic would let Roosevelt do it. Having a U-boat sink a DD once we were fighting the Japanese would seem to the newly roused US like a backstab of sorts.


Bill

 

[Tony Williams]

At the risk of annoying some here, an early warning of the Japanese attack is included in my novel 'The Foresight War'. However, it is the British who have the foreknowledge, not the Americans, and since they want the Japanese attack to go ahead so that the USA is drawn into the war they carefully judge exactly when to warn the Americans....too soon and the Japanese might call off the attack, or the USN might have time to get their battleships to sea, in which case they would probably be sunk if found - an even worse outcome than the historical one.

On another board there was heated debate about whether or not the US fighters could have done much to block the attack if they were warned in enough time to get fuelled, armed and airborne (i.e. about one hour in advance). I think they could; the Zeros were superior planes and their pilots more experienced, but there were fewer than 50 of them accompanying the first wave and less than 40 with the second, against around 100 P-40s and P-36s. Coupled with the US ships being closed up at action stations with all guns manned, I think that the attack would have been significantly disrupted and the damage greatly reduced.

Tony Williams: Military gun and ammunition website and Discussion forum

 

[Bill Cameron]

At the risk of annoying some here, an early warning of the Japanese attack is included in my novel 'The Foresight War'.

Tony,

Ka-CHING! Hope your book sales are going well!

Now onto the real bits of your post;

they carefully judge exactly when to warn the Americans....too soon and the Japanese might call off the attack, or the USN might have time to get their battleships to sea, in which case they would probably be sunk if found - an even worse outcome than the historical one.

Agreed. Nimitz said privately during the war and publically in his memoirs afterwards that the IJN finding the USN battleline at sea could have been a disaster.

On another board there was heated debate about whether or not the US fighters could have done much to block the attack if they were warned in enough time to get fuelled, armed and airborne (i.e. about one hour in advance).

Again, agreed. No matter how superior the Zeros and their pilots were numbers would tell.

Coupled with the US ships being closed up at action stations with all guns manned, I think that the attack would have been significantly disrupted and the damage greatly reduced.

Reduced damage to the ships certainly. If things got too hot over Ford Island, would Japanese pilots opt for their secondary targets; oil farms, dockyards, etc.? Nagumo should have hit the infrastructure first. Forcing the Pacific Fleet back to bases on the west coast would have been nearly as good as sinking it in total.


Bill

 

[Grimm Reaper]

Tony, the numbers of fighters on each side sound pretty even and given the superiority of the Zero, even a modest level of surprise, and the massive inferiority of the P-36 to either the P-40 or the Zero, it sounds like most of the Japanese strike craft will still get through.

The key issue would be that if the fighters are up and ready, then the battleships are operational, the doors and hatchways are not 'dogged open' and the AA is ready to go. Possibly the ships are already on the move, and the land-based AA is also going strong. In this case it would be a matter of degrees where each individual item doesn't do much harm to the IJN strike but cumulatively...

The novel is sounding even more interesting...

Bill, how could the IJN break off due to discovery or a more alert US military? Pearl was simply one of a series of attacks, which were to be followed by more operations over the next several months. If Nagumo had called it off, he would have been wise to 'do the honorable thing' as his fleet entered Japanese waters.

Now the US is provoked by strikes elsewhere, starting with Guam, Wake Island, the Philipines, etc and the battle fleet is untouched, so the US can deploy 8 battleships and hundreds of aircraft to the Dutch East Indies(or Philipines. Or Singapore). Meanwhile the two most modern American battleships and two more carriers are coming in from the Atlantic.

Given this clear threat, the IJN must be more cautious, and where do they go from there? An Anglo-American fleet of ten battleships smashing the invasion of the Dutch East Indies(long live radar!) with 100-150 P-40s and probably a few dozen Spitfires for cover, an American Pacific carrier force of 5 fleet carriers, and discussion as to how the British Indian Ocean forces can unite with the US to crush the IJN in late 1942.

Hitler really didn't have much of an alternative. What would he do? Stay out and let Japan be crushed, which he surely would have expected? Meanwhile the US is doing all the hard work in the Pacific, but is the US suspending Lend Lease, or is it still flowing? Meanwhile every British and Soviet man and gun in the Pacific can be pulled out.

Uncle Sam will take care of Japan.

The British forces saved would probably be sufficient to take North Africa and put Italy on the ropes, and as for the Soviet divisions and 3000 tanks that did not go west in late 1941...

 

[Bill Cameron]

Bill, how could the IJN break off due to discovery or a more alert US military? Pearl was simply one of a series of attacks, which were to be followed by more operations over the next several months. If Nagumo had called it off, he would have been wise to 'do the honorable thing' as his fleet entered Japanese waters.

Grimm,

The strike force left Hittokappu Bay at Etorofu Island (in the Kuriles) on the 28th of November and got at least daily sitreps about Pearl via the espionage service I wrote about earlier. The IJN expected losses; the 2 or 3 carriers others have mentioned, but they expected pay that price in return for putting the US Pacific Fleet out of action.

So what if the Japanese consulate on Oahu reported the Pacific Fleet sortied on the 2nd? Or the 5th? Would Nagumo still steam on and hit Pearl? His target is no longer there after all. I don't think Nagumo would be allowed to make the decision. Tokyo has the same information he does, they even get it sooner than he does. They would likely order Nagumo to call it off instead. Why take the risks to hit an empty harbor?

As you correctly point out, Pearl was just one of many operations. If Pearl is called off, the others will still occur and the war will begin anyway. Withdrawing from Pearl and that possible trap allows the IJN to save assets for the fight.

Now the US is provoked by strikes elsewhere...

The Japanese other operations are still underway and the US would be reacting to each as news arrived. The battleline can only be in 1 or 2 places at a time and wherever it shows up the First Air Fleet can be there too. Pearl taught the USN a lot of hard lessons, not all of the lessons it needed to learn (most of those others would be learned off Guadacanal), and learning those lessons in the open ocean instead of a shallow harbor will be costly.

Intercepting or interfering with IJN operations in the western and southwestern Pacific would tie the USN to an advance across the central Pacific, the very operation the IJN was designed to fight against.

Also, sending the Fleet to the Phillipines, Singapore, the Dutch East Indies, and all the rest would require certain supplies to present at those locations; they weren't, or a large fleet train accompany the Fleet; we didn't yet have one big enough.

(long live radar!)

A wee bit too soon for that. Long live radar in late '43 certainly. Long live radar in '42, sorry. Night adapted IJN lookouts routinely did better than USN radar sets in '42 and '43.

I think a 'No Pearl' or 'Aborted Pearl' Pacific War would see the Japanese initially take the many of the same targets they did in the OTL. Malaysia, the Indies, the PI, and Guam are just too distant and too many for the USN to effectively protect. The Japanese may take the northern PI on the first rush while the US moves heaven and earth to hang onto to the southern part in an ATL replay of Guadacanal.

There is one positive effect for the Japanese to a 'No/Aborted Pearl' beginning to the war, they most likely wouldn't develop such a bad case of victory disease.


Bill

 

[DuQuense]

In the lost Submariner TL a SSB Chief Engineer from Seattle [196x] is visiting his mothballed WW2 first ship when a flash of light deposits him, several subs, several aircraft carriers, and Cruisers and DDs in Philadelphia naval base. on Dec 4th 41.

In between lying to FDR about the the late forties thru sixties, he does tell about Pearl. As such the P40's are patrolling the north shore, the P36s are up over Pearl, And the Battle line catches up with the carriers off Midway.

It has a Three to one lost US /Japan due to the greenness of the US pilots.

 

[Bill Cameron]

And the Battle line catches up with the carriers off Midway.

DuQuense,

The six to seven knot slower US battleline caught the IJN strike force off Midway after a stern chase?

Pull the other one, it has bells on it.


Bill

 

[DuQuense]

No they had left Earlier, [pre informed remember] and where waiting off Midway on the Japanese return Course.

I think the Spy posts show it unlikely but ......

[ I didn't write it. just Goggled on it in SHWI while looking for Mike Ralls --USA 2002 in 1942 ISOT--]

 

[Tony Williams]

Tony, the numbers of fighters on each side sound pretty even and given the superiority of the Zero, even a modest level of surprise, and the massive inferiority of the P-36 to either the P-40 or the Zero, it sounds like most of the Japanese strike craft will still get through.

The inferiority of the US planes was not quite as bad as you might think. The P-40 had a similar top speed to the Zero, was less manoeuvrable but probably dived better and was tougher. Even the P-36 wasn't that far behind - there was probably a smaller performance gap between the P-36 and the Zero than there was between the Hurricane and the Bf 109 in the BoB.

One-on-one, small performance and handling advantages can become crucial, but in an all-out furball luck plays a large part, which is why many of the top aces preferred not getting caught up in a melee - they might accidently fly across the sights of some tyro.

Besides which, while the Zeros were tackling half the US fighters, the other half would have had a straight run at the bombers.

Tony Williams: Military gun and ammunition website and Discussion forum

 

[Karlos]

Back to Germany. If Hitler didn't declare war after Pearl Harbor, Rooselvet would find it difficult to declare war to Germany if heavily involved in the pacific, at least not until 1943 or so. No US involvement might have some influence in 1942. The first one I can think of is no Torch, no Tunisia german deployment, so maybe a different outcome in Stalingrad?

 

[Tony Williams]

That's one of the trickiest questions of the war IMO. Of course, in practice the USA was far from neutral - it was not only supplying the UK and USSR with vital war materials without which they would have been in dire trouble, the USN had also taken over responsibility for convoy escort in the Western Atlantic - in other words, they were hunting U-boats. The German Navy was certainly pressing Hitler to declare war so that they could take the gloves off and go for the American ships.

But if Hitler had refrained from declaring war - or even worse, decided to declare war on Japan in support of the USA - that would have comprehensively messed things up. All bets would be off as to the outcome.

Tony Williams: Military gun and ammunition website and Discussion forum