Preventing Pearl Harbor

Great Debates
1

It is late November in 1941. The United States has complete information about how and when the Japanese will attack Pearl Harbor and the Philippines. How do you stop the attack. Go out and meet the ships. Tell the world that you know about the plans?

And then there is the fall out of the Japanese government. Does the government fall because of the lost face. Does Yamamoto kill himself.

With the oil situation running low at the time which was responsible for taking the Dutch East Indies, they had to attack to continue to fight.

I just think that if we should have stopped the Pacific War if we could.

2

Do you think we did know?

3

Reported for a forum change. IMHO most likely, since there is no factual answer to these questions.

4

‘World War II might never have started, had the FAA been defending Pearl Harbor’

Japan 00, Are You Declaring an Emergency?

5

No I do not think that we did know about the attack. What I am asking is how could we have prevented the Japanese from following through on their plans to attack United States territories.

6

Moderator Action

It seems to me that there is enough of a debate here to give Great Debates a shot with this one.

Moving thread from GQ to GD.

7

Late November, 1941? You don’t.

The Philippines were gone no matter what. We didn’t have the forces in theater to counter the invasions, surprise attack or no. The Japanese knew that.

Pearl Harbor is a different story. They may very well have launched the attack anyway, and would have succeeded. Just a different body/ship count. We just got lucky the carriers were elsewhere on Dec. 7. If the IJN had caught them on the open seas, they could have pushed us all the way back to the mainland. That would have stretched the war out at least until 1946-7.

8

The disparity in resources between the US and Japan was so great, that a Japanese “victory” (defined as the US agreeing to a negotiated truce leaving the Japanese Empire plus conquests intact) was never going to be likely, under any scenario, once Japan had committed to war with the US – unless the US simply conceded.

There was simply no way the Japanese could remotely hope to compete with the US in building naval strength. No amount of naval genius on the Japanese part could compensate for such a one-sided build up of force against them.

http://warfarehistorynetwork.com/daily/wwii/how-japans-carrier-construction-was-thwarted/

The Japanese gambled everything on their initial attacks simply demoralizing the Americans, and the war stood or fell on how well that demoralization succeeded …

9

Oh, most certainly. Once “The Arsenal of Democracy” got really rolling, they were toast. The only question was “How well-done?” would that toast be?

10

By November 1st (I’m going to cast a wide net on this one, since ‘late’ is open to interpretation), Japan has been embargoed by the United States, and FDR has already declared his two ocean navy program. Japan historically, and in this scenario, feels that acting quickly and decisively is its only major way to preserve its empire, including shaky gains in China.

One problem here is that FDR doesn’t necessarily want war with Japan. FDR is gravely concerned about Nazi Germany, and the scenario gives him zero knowledge that Germany will promptly declare war on the United States after Pearl Harbor. Obviously, Pearl Harbor and the Far East can be put at high alert (and this probably causes Japan to suspect some kind of infiltration of its secret communications)

FDR could, potentially, give Japan a small way out and avert Pearl Harbor. Something like switching the embargo to a duty on oil exports might be enough for Japan to call off the campaign. This may be more likely if FDR decides to inform Winston Churchill, as the UK wasn’t spoiling for a fight with Japan here either.

Military Preparedness at Pearl Harbor isn’t going to stop the Pearl Harbor Bombings. Ironically, trying to sortie ships to attack the IJN could lead to the loss of US Carriers; it is ultimately those Carriers that won the war in the Pacific. I suppose there are questions about how much knowledge the US has about the intended attack on Pearl; obviously, jumping the IJN’s own Carriers would put the USN into a dominant position where Japan may be unable to seize the Dutch East Indies. The opposite scenario, where the USN has several battleships it lost at Pearl Harbor but has suffered losses in Carriers, could potentially be worse than historical.

Now, we shouldn’t exaggerate the scope of this either; the US Navy will gain superiority in Carriers in 1943 or 1944 by dint of production. But this is a grossly different Pacific War; Japan probably gets stalled in Mainland Australia or India proper–either of these scenarios almost certainly has knock-on effects in the Middle East and the rest of the war. If ANZAC forces are forced to redeploy to defend their homes, does the Africa Korps have enough to prevail against 8th Army and take the Suez Canal? If Japan decides to make some kind of play for an ‘Independent India’, does this create another meat grinder that the Allies are forced to divert resources against?

If the USN is able to jump the IJN Carriers, this advances one critical military operation: D-Day.

MacArthur basically delayed D-Day because of the large amount of resources being diverted to prevail in Guadalcanal. But there’s no Guadalcanal campaign if the IJN can’t project naval power. D-Day would be attempted in 1943. There would be no Italian Front–and perhaps the Western Allies make more progress in Liberating Europe if the Soviet Union isn’t able to cover as much ground. D-Day 1943 has its own risks, but Germany is itself tied down against the Soviet Union, and the Western Allies probably get more out of this campaign than the Italian Campaign.

11

Which raises another series of questions - Could we have successfully ambushed the Japanese carriers before or during the attack? The reasons we nailed them so hard at Midway were that we were fairly equal in strength, didn’t fall for the Aleutians ruse, and got hella lucky. At Pearl we would have had the Enterprise and the Lexington. The Saratoga was way over in San Diego by Dec. 7. But even with her it’s a 3:6 battle, and the IJN hasn’t lost the air crews they lost at Coral Sea.

Question 2 - If you do get the drop on them, is it better to attack before they launch the raid, or after? I’m going to say after, just to get all those Zeros out of the picture.

12

If the Japanese had learned in advance that the Americans were wise to their plans to bomb Pearl Harbor, I suspect the mission would have been aborted.

The impetus to start a war was well in place. but at that time, losing the element of surprise probably would’ve led to the attack’s cancellation (too much risk involved).

13

Which leads to the question: If the Pearl Harbor raid had been aborted, when(if ever) would we have entered the war?

14

There are conspiracy theories out there that suggest Roosevelt knew an attack was coming and they have some evidence to make it seem plausible.

15

I would think if the attack was expected, the number of aircraft known and their planned targets, the US military would have been ready with antiaircraft guns manned, birds in the air, continuous radar operation, spotters on rooftops, and destroyers out of port. Only 24 hours notice would be needed for that, even if the carriers couldn’t show up in time. Just for the Japanese to lose the element of surprise would make a major difference.

What might happen in the aftermath, I don’t know.

16

This never struck me as a good conspiracy theory.

I mean, the theory is that Roosevelt knew the Japanese were going to attack and deliberately did nothing, hoping a successful attack on the US would drag the US into war.

However, this makes no sense, for one simple reason: a failed attack would drag the US into war just as much as a successful attack.

17

The other problem with this conspiracy theory is that Roosevelt didn’t want to go to war with Japan. He wanted to go to war with Germany.

18

The Philippines invasion alone would have been enough to constitute war on the US. Pearl Harbor added visuals and shock value.

19

Yeah, and there was no guarantee that Hitler would kick the most massive own goal in history and, in a fit of irrational exuberance, declare war on the US just because Japan attacked the US.

The treaty Germany had with Japan did not require this (not that the Nazis ever paid attention to treaties :D). Only if Japan was attacked, would Germany have been obliged to defend them.

Roosevelt could easily have ended up in an entirely separate war with Japan, with war with Germany no closer than before.

20

I recall reading — sorry, I can’t remember where offhand — that the attack could take place only if two conditions were met: the receipt of the “Climb Mount Niitaka” message (indicating that diplomacy had failed), and the strike force (Kido Butai) remaining undetected. If Admiral Nagumo determined that his cover had been blown, he was to turn around and return to Japan.

As would be seen several times during the war, the Japanese plan depended on precise timing: the declaration of war was to be delivered before the attack, but only barely. This would adhere to the letter (if not the spirit) of international diplomacy, while retaining the element of tactical surprise. As it turned out, of course, decoding problems with at the Japanese embassy delayed delivery until later, making it a “sneak attack” rather than a “surprise attack.” Not that semantics would have made any difference in the US response.

(Incidentally, Admiral Nimitz is reported to have said that the outcome could have been much worse: if Admiral Kimmel had received advance notice, he would undoubtedly have sortied the fleet to meet the Japanese — and without air cover, been defeated on blue water with a much higher butcher’s bill and no chance to salvage the ships sunk.)