Pearl Harbor thought.

[Dread Knot]

Admiral Nagumo goes swimming and I think you will likely end up with a super-Midway event. The Japanese are bringing six carriers and veteran pilots true, but in this case Oahu is a far more formidable installation than Midway, capable of basing and dispatching far more aircraft into the air. As always, a lot depends on who gest the first blow in, but foreknowledge is a huge advantage. The only fly in the ointment might be if the US carriers are spotted early by Japanese search planes. Nagumo might elect to retreat at that point.

Even if both carrier fleets end up in a shambles, USN pilots and personnel are far more likely to be rescued by their side than Kido Butai pilots.

[mapuc]

My first impression? The war would end a lot earlier.

Markus

[Dread Knot]

Of course, one political drawback might be no declaration of war by Hitler after seeing his ally in the Pacific getting an embarrassing thumping early on. That puts Roosevelt over a barrel in Congress, trying to get involved in the war in Europe, while one is already raging in the Pacific.

[Admiral Halsey]

Originally Posted by Dread Knot

Of course, one political drawback might be no declaration of war by Hitler after seeing his ally in the Pacific getting an embarrassing thumping early on. That puts Roosevelt over a barrel in Congress, trying to get involved in the war in Europe, while one is already raging in the Pacific.

True but Hitler might be insane enough to still declare war. As for Nagumo retreating he'd have no choice but to fight it out at that point. He'd know that it couldn't be a coincidence that there are American carriers waiting for him on his flank.

[CCIP]

My favourite response to this kind of thing is that real historians hate what-ifs

The real question is just how they would know that much operational detail about the way the Japanese would carry out the Pearl attack. It's one thing to know that the Japanese might attack, another thing to know the exact composition of the task force and attack plan and tactics, and being able to find the ships without the Japanese putting up necessary precautions. And radar during that time didn't really have a great deal of precision, or at least I don't think there was quite that much operational experience in its use. So, that's quite the gamble. I don't think there would be enough confidence in this working.

Something like this would be basically threading the eye of the needle - sure, maybe, but it's one of those things where a whole bunch of things would conveniently have to turn out precisely right for the Americans to pull it off, against an already-wary Japanese task force (they themselves knew they were running big risks, which is why they got out of there fast instead of sending another wave of attacks). Considering this would all be happening while their planes were bombing American soil, I don't think this kind of plan would be approved. Too many things that could go wrong at too high a cost.

[Admiral Halsey]

Originally Posted by CCIP

My favourite response to this kind of thing is that real historians hate what-ifs

The real question is just how they would know that much operational detail about the way the Japanese would carry out the Pearl attack. It's one thing to know that the Japanese might attack, another thing to know the exact composition of the task force and attack plan and tactics, and being able to find the ships without the Japanese putting up necessary precautions. And radar during that time didn't really have a great deal of precision, or at least I don't think there was quite that much operational experience in its use. So, that's quite the gamble. I don't think there would be enough confidence in this working.

Something like this would be basically threading the eye of the needle - sure, maybe, but it's one of those things where a whole bunch of things would conveniently have to turn out precisely right for the Americans to pull it off, against an already-wary Japanese task force (they themselves knew they were running big risks, which is why they got out of there fast instead of sending another wave of attacks). Considering this would all be happening while their planes were bombing American soil, I don't think this kind of plan would be approved. Too many things that could go wrong at too high a cost.

But at the same time the rewards would be extraordinary. Think about how different the Pacific war would go if in one swoop not only is Pearl saved(Remember the moment the radar station confirms it's the Japanese coming in Peal goes to full alert) or not heavily damaged and the majority of Japan's carriers are wiped out. Also Midway was a threading the needle type situation and it worked perfectly then and is this case you'd have nearly the same scenario.

[CCIP]

Of course. But again, I think the only way this would actually fly is if somehow the fog of war disappeared completely. I just don't see how Americans would have access to that level of detail about Yamamoto's attack plans - it would be an extraordinary achievement of intelligence. You'd probably have to have an IJN rear admiral working as a spy for the Americans to really make it work.

[Wolferz]

There was no radar in '41 so no IJN plane could have been spotted except with the MKII eyeball.

[CCIP]

Originally Posted by Wolferz

There was no radar in '41 so no IJN plane could have been spotted except with the MKII eyeball.

That's not true. Opana was opened in 1939, using a 1937-model radar. I would seriously doubt the performance of that radar in any sort of precision, but it did detect the Japanese coming in to bomb Pearl, about 40 minutes before the bombing commenced. They thought it was just a flight of B-17s doing training, then they lost contact, and the warning wasn't passed on. So much for precision.