WI: Kido Butai Spotted En Route to Pearl

It would depend on when the Japanese Task Force was spotted according their instructions:
Fantastic information, thank you so much. For the first time ever, I see a clear and concise 'approach protocol' for Kido Butai that deals with the possibility of being discovered en route, all the way down to specific timings - our hypothetical scenario sort of jibes with #2. I note the account emphatically states that no shipping was encountered whatsoever during the approach, which refutes earlier talk in this thread of the force having crossed paths with a Soviet vessel.
 
Really?

I am not sure I see the US opening hostilities as much as many in the chain of command might want to.

Having worked so hard to remain neutral to this point in the face of Axis provocation and Allied invocation it would be a strange change to suddenly throw that away on a battle fleet steaming in international waters on a heading away from US territory.
The American public was already outraged by Japanese atrocities in China. President Roosevelt had already ordered the US Navy to sink German ships on sight, with the support of the majority of the American public.
 
They were under orders to turn back if spotted
It was supposed to be a surprise attack if they were spotted it would turn into a head-to-head slugging match.
The Japanese Admirals knew that even if they were able to win they would have lost enough ships to make a War unwinnable
 
The American public was already outraged by Japanese atrocities in China. President Roosevelt had already ordered the US Navy to sink German ships on sight, with the support of the majority of the American public.
Something that many people continue to overlook or otherwise not be aware about.
 
I presume there are threads around here about how Pearl would have gone with 24 hours notice (rather than 3 days). If there are, I would appreciate someone pointing them out to me.

That said, my tentative feel is that ~24 hours notice (US merchant ship sees, say, some flanking destroyers of the Japanese force and gets off at least position and heading info to Pearl) would most likely dramatically blunt the effectiveness of the Japanese and increase the chance of American forces (especially submarines) doing damage to some of the capital ships.

With some notice, one presumes that:
1) Subs are redirected to intercept
2) Scout planes are launched early AM Dec 7
3) Radar is on high alert and believed
4) Fighters mostly get scrambled
5) AA guns more operational and effective

I think there were also issues with some Pearl ships not being in watertight mode? And I'm not sure if torpedo nets could have been deployed in 24 hours. Not sure how many, if any, of the Pearl ships would deploy to sea if there were strong indications of an imminently approaching Japanese task force.
 
That said, my tentative feel is that ~24 hours notice (US merchant ship sees, say, some flanking destroyers of the Japanese force and gets off at least position and heading info to Pearl) would most likely dramatically blunt the effectiveness of the Japanese and increase the chance of American forces (especially submarines) doing damage to some of the capital ships.
All that the defending Americans would really need to do to ensure that the attack fails is annihilate Murata's 40-odd torpedo planes, since those were the only viable ship-killers amongst the attacking aircraft and wound up dealing the most damage IOTL.

Not hard to do, given that the pursuit squadrons based on Oahu outnumbered Itaya's escorting Zeroes by more than 2:1 and alert AAA would pose a formidable gauntlet.

IOTL Itaya's boys did not fly close escort with the torpedo planes or even the dive and level bombers, but ranged well ahead of their charges to strafe the airfields, leaving them virtually unprotected during their torpedo and bombing runs - very reckless. Even if they do switch to flying close escort in the event of realising that the Americans are expecting them, they're almost certainly going to be overwhelmed by a swarm of P-40s and P-36s.
 
All that the defending Americans would really need to do to ensure that the attack fails is annihilate Murata's 40-odd torpedo planes, since those were the only viable ship-killers amongst the attacking aircraft and wound up dealing the most damage IOTL.

Not hard to do, given that the pursuit squadrons based on Oahu outnumbered Itaya's escorting Zeroes by more than 2:1 and alert AAA would pose a formidable gauntlet.

IOTL Itaya's boys did not fly close escort with the torpedo planes or even the dive and level bombers, but ranged well ahead of their charges to strafe the airfields, leaving them virtually unprotected during their torpedo and bombing runs - very reckless. Even if they do switch to flying close escort in the event of realising that the Americans are expecting them, they're almost certainly going to be overwhelmed by a swarm of P-40s and P-36s.
i agree entirely with your points - however I also note that Clark Field had three different pursuit formations in the air and none of them managed to intercept the G4M strike that wiped out half of the FEAF's B-17s in one fell swoop.

It's just as possible that the torpedo planes and level bombers proceed serenely to annihilate Battleship Row as OTL, while the pursuit squadrons get into turning fights over their airfields and actually end up with the worse of the exchange because they are playing to the A6Ms' strengths.

Of course, there's also plenty of time for the Pacific Fleet to just have weighed anchor, with a range of outcomes from the unlikely (steam in circles 150 nm SE of Pearl until Nagumo gives up and goes home) to the disastrous (sails to meet KB but is detected and struck in open water, where sunk BBs cannot be refloated and the butcher's bill is grotesquely higher) to the Ameriwank (radar picks up KB before dawn and Fuchida never gets to launch because 2 BCs and 2 floatplane CAs are wholly inadequate to face half a dozen Standards and Leahy's cruisers are faster than Nagumo's carriers so they are all set ablaze and sunk).
 
I was always curious how the Pacific fleet would have fared against the Japanese strike force at sea. Lets say PH gets 36-24 hour advanced notice, how would the resulting sea battle have played out? The US had the advantage in battleships, and I believe Lexington and Enterprise might have close enough to participate (but with inexperienced aircrews),. The Japanese only have two battleships, but they have all those carriers, and arguably the best carrier based strike force in the world.

ric350
 
On a heading TOWARDS US territory.

There is no way the Japanese can innocently explain why a huge attack fleet is Hawaii bound during a time of failing negotiations, international waters or otherwise.

This action can be interpreted as an opening of hostilities on their part and I very much doubt any reasonable observer, even without the benefit of hindsight, can infer otherwise.

In any case, our hypothetical scenario already has Kido Butai open fire and eliminate the craft that spotted them, which removes any lingering doubt that might surround the issue.

Do you really think Kido Butai, if spotted, would opt to hold their fire and calmly change course?
If, and it's a big if, the Japanese turn back after being sighted then there's not much the US can do without being seen as the aggressor. So long as they're still in international waters the Japanese can claim they're just on a training exercise and they have every legal right to go where they wish due to the Freedom of the Seas.
 
If, and it's a big if, the Japanese turn back after being sighted then there's not much the US can do without being seen as the aggressor. So long as they're still in international waters the Japanese can claim they're just on a training exercise and they have every legal right to go where they wish due to the Freedom of the Seas.
A training exercise? That far away from home, and Hawaii bound before making the turn? Nobody could possibly accept that kind of explanation with a straight face.
 
And nobody can prove that the Japanese were lying.
Now here's a question. Suppose the Americans had SIGINT that could prove Japanese deception in this matter. Would they be willing to disclose their ability to read Japanese codes in the name of proving to the world that the Japanese are being sneaky?
 
Now here's a question. Suppose the Americans had SIGINT that could prove Japanese deception in this matter. Would they be willing to disclose their ability to read Japanese codes in the name of proving to the world that the Japanese are being sneaky?
Not a chance. They now know for certain that war is coming in the next year. Being able to read the enemy's signals is worth much, much more than scoring a few diplomatic points in the run up.
 

marathag

Kicked
And nobody can prove that the Japanese were lying.
If they were 'training' on the other side of the International Date Line, only the Germans and Italians, and only some of the most deluded local Isolationists would believe that load of bullshit.

Halsey would get a ticker tape parade for attacking any Japanese force within a thousand miles of Pearl Harbor, no matter that it
was peacetime.
Issued order

U.S.S. ENTERPRISE

At Sea
November 28, 1941

BATTLE ORDER NUMBER ONE

1. The ENTERPRISE is now operating under war conditions.

2. At any time, day or night, we must be ready for instant action.

3. Hostile submarines may be encountered.

4. The importance of every officer and man being specially alert and vigilant while on watch at his battle station must be fully realized by all hands.

5. The failure of one man to carry out his assigned task promptly, particularly the lookouts, those manning the batteries, and all those on watch on the deck, might result in great loss of life and even loss of the ship.

6. The Captain is confident all hands will prove equal to any emergency that may develop.

7. It is part of the tradition of our Navy that, when put to the test, all hands keep cool, keep their heads, and FIGHT.

8. Steady nerves and stout hearts are needed now.

G. D. MURRAY,
Captain, U.S. Navy
Commanding

Approved: November 28, 1941.
W. F. HALSEY,
Vice Admiral, U.S. Navy,
Commander Aircraft, Battle Force
 
I would LOVE to know more about this incident. It appears to have escaped my knowledge entirely, up until now. If it did occur, and the attack went ahead anyway, one can only presume that the neutrality pact between Japan and the Soviets somehow prevented the encounter from ending in violence and disclosure.
It occurred on either 2 or 3 December when the Kido Butai was either due north or slightly northeast of Midway, and at a distance far beyond any normal patrol search from Midway during peacetime. The sighting of a Russian freighter caught the Japanese completely by surprise causing momentary confusion. Luckily for Nagumo, the weather was atrocious and the Russians probably never sighted the Japanese fleet. Nagumo is reported to have issued orders on 4 Dec, about the time his fleet turned south for the final run in to Hawaii, that his surface combatants were to sink any enemy or neutral ship that might broadcast their presence.

The Miraculous Torpedo Squadron by Jūzõ Mori, Kindle Edition, Location 1634/4126
"The next day (Dec 2 or 3, 1941) we received news that a Russian freighter was on course to cross our path. The report apparently came from one of our submarines scouting ahead of the strike force. This was a serious matter. “We’ve got no choice, we’ll have to sink her.” “No, we can’t do that.” “I think the sub’s gonna sink ‘er.” Of course, we all had our own ideas about what should, or shouldn’t, be done. But if a foreign ship should sight the strike force just prior to the attack all our efforts would be in vain. It was one of those small, unforeseen events that could have major consequences. I figured that we had no other choice but to sink her. Thankfully, the thick fog hid us from each other and we continued on our respective ways. But it was a close call. The next day everyone had calmed down. It seemed the Russian freighter had changed course due to the rough seas. We were all greatly relieved."
 
Nearly 81 years after the event it's easy for us to find it incredible that so many clues were failed to be reported properly or that intelligence analysts failed to link the clues they had together to provide irrefutable evidence that the Japanese were about to go to war with Great Britain, the Dutch and the U.S.

The US had SIGINT clues, without revealing any code breaking secrets, that Japan might be about to strike U.S. assets as far east as Hawaii or Dutch harbor. Contrary to the popular notion that the Kido Butai was observing complete radio silence, John Toland in "Infamy" pp.291-294 relates how multiple very strange radio intercepts with RDF bearings were reported to USN 12th (San Francisco) and 14th (Pearl Harbor) District Headquarters but action was not taken.

On 30 November, radio operators on the SS Lurline enroute to Hawaii began to pick up and record strange Japanese transmissions northwest by west of their position coming from an area of the stormy North Pacific that was usually void of shipping that time of year. A more than 2 hour series of transmissions from JCS Yokohama was being broadcast in code that were being acknowledged by repeat back verbatim by station JOC and others somewhere in the North Pacific, "possibly for copying by crafts with small antennas." The lengthy transmissions were good enough to get RDF bearings. In 30 years, the operators had never heard JCS Yokohama broadcast before 9PM and then have the entire transmission rebroadcast on the lower marine frequency from somewhere in the Pacific. They felt the situation so unusual that they kept a detailed log to present to naval authorities when they arrived in Honolulu on 3 Dec. The next night, 1 Dec, it happened again, and again, but even stronger transmissions were recorded on 2 Dec. Something was happening, but what? (Toland, Infamy pp.291-293)

12th Naval District Intelligence (San Fransisco) was also involved in the hunt for the possibly missing Japanese carrier task force and analysts were collating reports from commercial ships and the 4 wire services. One of the wire services reported queer signals west of Hawaii on a frequency that didn't make sense. Other services and shipping companies were asked if they were getting strange signals, and several confirmed that they had. Plotting signal bearings on a large chart, they located where the bearings intersected and reported to the 12th Naval District Intelligence Chief, Captain Richard T. McCollough, that this could be a Japanese carrier force operating near Hawaii. (Toland, Infamy pp. 293-294)

Now, back to the Russian freighter: If the freighter had come under attack by Kido Butai cruisers and destroyers and had time to get off an RRRR, under attack by surface warships! and broadcast their position before being sunk...naval intelligence analysts will now have a clear picture of Kido Butai's location and hostile intent. Long range submarine and aircraft patrols could begin actively seeking the carrier force.

Even if not pinpointed and engaged in the North Pacific 4-5 days before the intended Pearl Harbor attack date, Nagumo and Japan are screwed! The surprise needed for success is gone, there is no plausible peaceful reason for the Kido Butai to have been discovered where they are, and now they've gone and sunk a neutral vessel. Nagumo will be forced to break off and return to Japan without attacking and will likely commit suicide. The sham negotiations in Washington blow up, Russia tears up its Non-Aggression Pact with Japan, public opinion goes from being isolationist to Gung Ho and the U.S. goes on a war footing.
 
Had any advance warning been issued, how would Lieutenant Kermit Tyler at Fort Shafter’s Intercept Center have evaluated the radar contact from the Opana Radar site?
 
It occurred on either 2 or 3 December when the Kido Butai was either due north or slightly northeast of Midway, and at a distance far beyond any normal patrol search from Midway during peacetime...

Nagumo is reported to have issued orders on 4 Dec, about the time his fleet turned south for the final run in to Hawaii, that his surface combatants were to sink any enemy or neutral ship that might broadcast their presence.
Thank you so much; I completely missed this one, despite owning a copy of Juzo Mori's book. Now we understand why nothing happpened; the Soviet vessel was spotted by a sub scouting ahead for Kido Butai and it never came within spotting distance of the fleet.

The bolded portion really should quash any notion that the Japanese would have acted innocent and calmly turned around if spotted.
 
Had any advance warning been issued, how would Lieutenant Kermit Tyler at Fort Shafter’s Intercept Center have evaluated the radar contact from the Opana Radar site?
Full alert would probably have the radar operators interpret anything on their screens as hostile. I predict at least one friendly fire incident occurring as a result.
 
i agree entirely with your points - however I also note that Clark Field had three different pursuit formations in the air and none of them managed to intercept the G4M strike that wiped out half of the FEAF's B-17s in one fell swoop.

It's just as possible that the torpedo planes and level bombers proceed serenely to annihilate Battleship Row as OTL, while the pursuit squadrons get into turning fights over their airfields and actually end up with the worse of the exchange because they are playing to the A6Ms' strengths.
IOTL the Clark Field pursuit squadrons were caught wrong footed and outnumbered by Yokoyama and Shingo's A6Ms - not all that many of them were airborne. Had they been ready and waiting, the rikkos might have suffered. Will thoroughly concede that given how the American pilots had exactly nil knowledge of how to fight the A6M, they might suffer serious casualties in turning fights against their more agile enemies, but at the end of the day I foresee sheer numbers ultimately prevailing.
 
Top