Could Pearl Harbor be delayed?

Simple, two part question: could Pearl Harbor have been delayed? If so how long?

Not for very long at all IF my understanding of the situation is correct.

As I understand it a delay of six months would have meant a much tougher fight in the Philippines for example. The army being created for the planned independent country had just begun training. Most of the artillery men had never seen their weapons fired. The rest had seen one fired but never done it themselves. That was the state of things for the army as a whole when the Japanese invaded.

Give the trainers six months and the recruits would have been trained soldiers with a bit of experience. That would have made them a much tougher proposition than what was actually faced, and the proposed army was not small. A failed invasion of the Philippines would have screwed the entire plan.

Wake would have had more work finished on its defences, they might even have been finished. Maybe not enough to hold indefinitely but it would have been even messier than it was, and the plan could not afford delay or serious casualties in forces that had to move on for other conquests.

Hawaii would have had more patrol aircraft - the B-17's that arrived during the attack might have been used for this for example.
 

fred1451

Banned
Not for very long at all IF my understanding of the situation is correct.

As I understand it a delay of six months would have meant a much tougher fight in the Philippines for example. The army being created for the planned independent country had just begun training. Most of the artillery men had never seen their weapons fired. The rest had seen one fired but never done it themselves. That was the state of things for the army as a whole when the Japanese invaded.

Give the trainers six months and the recruits would have been trained soldiers with a bit of experience. That would have made them a much tougher proposition than what was actually faced, and the proposed army was not small. A failed invasion of the Philippines would have screwed the entire plan.

Wake would have had more work finished on its defences, they might even have been finished. Maybe not enough to hold indefinitely but it would have been even messier than it was, and the plan could not afford delay or serious casualties in forces that had to move on for other conquests.

Hawaii would have had more patrol aircraft - the B-17's that arrived during the attack might have been used for this for example.
Plus don't forget the 'Two Ocean Fleet' was coming, the longer they wait, the less time they have to do things before it starts rolling out.
 
wasn't the planning dependent on the amount of carriers available?
so if there is a fire during the construction of the latest carrier, that would delay it.
 

Saphroneth

Banned
Also the commissioning dates of the aircraft carriers play in here.



As of start of 1941

US fleet carriers:
Lexington
Saratoga
Yorktown
Enterprise
Wasp


Japanese fleet carriers

Akagi
Kaga
Soryu
Hiryu


During 1941

US:

Hornet (20 Oct)

Japan:

Shokaku (8 August)
Zuikaku (26 August)


And the US is building... the Essex class, which will by mid-1942 have six ships on the slips and will eventually result in a build of twenty-four ships. That one class will outnumber both pre-war CV fleets... twice over.


As for battleships, the Japanese are awaiting the Musashi and the Shinano, and the Americans will commission in early 1942 three powerful and very modern battleships (SoDaks) with another fitting out and the faster Iowas (six of them) on the ways.
 

CalBear

Moderator
Donor
Monthly Donor
Could it be delayed? Sure.

Should it be delayed (assuming it is ever going to happen)? Probably not.

The Japanese chose almost literally the first Sunday they could manage the strike after Zuikaku finished her shakedown. That gave the Kido Butai the six decks it needed to conduct the strike as planned, and Sunday had been identified as the ideal day to make the attack thanks to the U.S. forces maintaining what was effectively banker's hours.

Every week the Japanese wait, the Americans get stronger. Wake's defenses come closer to completion and the runway expansion come closer to reaching B-17 staging. The Philippines receive more supplies, more aircraft, more U.S. troops. More U.S. ships of all types are ready for deployment, some within weeks, other within a couple months. Replacement aircraft for the obsolescent ones in service arrive by June (the first half squadron of Avengers were actually used at Midway).

The British are also not sitting on their hands. They have finally recognized that the Japanese might be a real threat. Additional forces are being deployed to Malaya, especially air units and warships. the Dutch authorities are starting to receive the aircraft they ordered from the U.S. The Australians are starting to reinforce places like Rabaul.

Japan, on the other hand, has nothing in the immediate pipeline to counterbalance any of this. All they are doing is using up more and more of their fuel reserves (the IJA estimated that it had less than 12 months reserves available, at current usage, before the massive expansion of the war) while wathing their opponents improve.

Why wouldn't they attack as soon as the could? Attacking was lunacy, the timing wasn't.
 
What CalBear said.

The Japanese had a very narrow window of opportunity, and they knew it.

If one of the carriers is a bit late, they could push it out a week or two or so, but that's about it.

They NEED to attack basically the minute they have all 6, if they're going to do it at all.
 
In addition to all the urgent considerations noted by Calbear

The Japanese are also running out of oil. They had enough reserves to run the fleet and air services at war tempo for most of a year, and then...

The longer you wait, the more you draw down those reserves, even at reduced tempos. Japan had very little oil production in its prewar territories.

Which is another consideration: the oil facilities - well, refineries, storage, etc. - in the East Indies become harder to take intact the longer you wait. The British and the Dutch have longer to make sabotage arrangements, or even defend them (at least in the case of the refineries on Singapore).

If anything, Japan would have been better off going to war sooner in 1941 - which she would have, if the Fifth Carrier Division had been ready for it.

EDIT: I see Calbear hit that in his last paragraph - that's what I get for reading too hastily.
 
The Japanese are also running out of oil. They had enough reserves to run the fleet and air services at war tempo for most of a year, and then...

The longer you wait, the more you draw down those reserves, even at reduced tempos. Japan had very little oil production in its prewar territories.

Which is another consideration: the oil facilities - well, refineries, storage, etc. - in the East Indies become harder to take intact the longer you wait. The British and the Dutch have longer to make sabotage arrangements, or even defend them (at least in the case of the refineries on Singapore).

If anything, Japan would have been better off going to war sooner in 1941 - which she would have, if the Fifth Carrier Division had been ready for it.

EDIT: I see Calbear hit that in his last paragraph - that's what I get for reading too hastily.


Speaking of which, and sorry of dragging this too off-topic, but when the US imposed the metal and oil embargos on Japan, what were their requirements, if any, to resume metal and oil deliveries?

On another hand, what is the feasability of switching most of the fleet to at least partially coal fired boilers? They did had such ships apparently during the WW1 years and into the twenties (like Akagi and Kaga), and were trying the same type of conversion in 1945. Is that even feasible? Have i read correctly that Japan did had substantial coal reserves?

Again, sorry if i'm detouring the topic too much.
 

CalBear

Moderator
Donor
Monthly Donor
Speaking of which, and sorry of dragging this too off-topic, but when the US imposed the metal and oil embargos on Japan, what were their requirements, if any, to resume metal and oil deliveries?

On another hand, what is the feasability of switching most of the fleet to at least partially coal fired boilers? They did had such ships apparently during the WW1 years and into the twenties (like Akagi and Kaga), and were trying the same type of conversion in 1945. Is that even feasible? Have i read correctly that Japan did had substantial coal reserves?

Again, sorry if i'm detouring the topic too much.

As to the embargo, the requirement was to withdraw from French Indochina. Effectively annexing France's colonies, not the war in China, as is sometimes believed, was what brought the hammer down on Tokyo. The U.S. had told Japan flat out not to do it, or else. They did it and the U.S. (and it need to be noted, UK/Commonwealth) followed through.

They might have been able to make the conversions, but it would have taken the ship(s) involved out of service for months. There would also be the need to remove fuel tanks and replace them with coal bunkers, change bulkheads to allow movement of the coal to the boiler room, add personnel (and berthing) to stoke the boilers (i.e. throw in the coal into the furnace), and change the configuration of the hull to add coal chutes. The carriers will need their islands to be redesigned, the deck level funnels that worked with fuel oil will be... sub-optimal with coal. Pretty much change the ship completely. The ships will also likely lose a couple knots, and a ton of range, oil is vastly more efficient as fuel source than coal.

The other issue then is that you need a whole fleet of colliers to keep the ships supplied as well as moving massive qualities of coal to the Mandates, Korea, and Formosa. there will also need to be more infrastructure put into place to allow large volume coaling, since warships will burn much more, and much more quickly, than fuel oil. Coaling is also massively labor intensive, increasing turn around time.

Using coal on carriers will also have the potential to serious complicate flight operations due to the quantity of smoke produced while at high enough speed to conduct flight operations.
 
Speaking of which, and sorry of dragging this too off-topic, but when the US imposed the metal and oil embargos on Japan, what were their requirements, if any, to resume metal and oil deliveries?

On another hand, what is the feasability of switching most of the fleet to at least partially coal fired boilers? They did had such ships apparently during the WW1 years and into the twenties (like Akagi and Kaga), and were trying the same type of conversion in 1945. Is that even feasible? Have i read correctly that Japan did had substantial coal reserves?

Again, sorry if i'm detouring the topic too much.

The U.S. embargo was triggered in July 1941 by Japan's move into Southern French Indochina, securing bases from which it could easily strike British Malaya and the Netherlands East Indies. So it was clear that a withdrawal from Indochina was the absolute minimum that Roosevelt expected as a concession at that point. But that was not likely to be enough. It was becoming evident through the drawn-out (and futile) negotiations for a summit between Prince Konoye and Roosevelt in Hawaii that Roosevelt felt he needed Chiang's support, along with Churchill's, for any deal, and that was certainly going to involve something more than just a pullout from Indochina. And that position only hardened once Stanley K. Hornbeck came on board as Hull's principal adviser at State.

In any event, Roosevelt hardened his position when negotiations intensified in the fall - you need to read the Hull Note (Nov. 26, 1941) for what the U.S. now expected. In short: withdrawal from not only Indochina but also China as well, and recognition of Chiang's government, and surrender of all extraterritorial rights in China. It was left unclear by the note whether that would include the Japanese puppet state of Manchukuo (I am inclined to think not).

It's a fair question whether Roosevelt might have settled for something short of all that, had the Japanese offered something concrete in the summer or early fall of 1941 - for example, a unilateral withdrawal from Indochina and an agreement for a cease-fire in China followed by negotiations with Chiang. Such a gesture might have cut the ground out from under White House bellicosity, possibly. But to imagine a Japanese leadership in 1941 agreeing to such terms, and a Japanese Army willing to permit it without something like a military coup, seems to be a fairly far-fetched exercise, I'm afraid.
 
As to the embargo, the requirement was to withdraw from French Indochina. Effectively annexing France's colonies, not the war in China, as is sometimes believed, was what brought the hammer down on Tokyo. The U.S. had told Japan flat out not to do it, or else. They did it and the U.S. (and it need to be noted, UK/Commonwealth) followed through.

Unquestionably Indochina triggered the embargo.

The difficulty is whether mere withdrawal would have lifted the embargo. Or did FDR's demands escalate after putting the embargo in place? Was Roosevelt raising the ante after that?

Be an interesting exercise whether a unilateral withdrawal would have forced FDR to pull the embargo. My guess, which is just a guess, is that it would have caused Roosevelt to lift only part of it, while maintaining pressure for a deal over China as well. I could be wrong. The longer it dragged out, the more FDR's position seemed to harden.

Of course, I wouldn't give five cent's for Konoye's life if he had simply ordered such a thing. He'd likely have to live on board Nagato with Yamamoto to keep from being used as target practice by army assassins, and I seriously wonder whether the Army would even obey the order to withdraw.
 
mack8 you're fine, this is actually something I was going to bring up.
--------------

What if the French had agreed to close the Yunnan Railway like the Japanese wanted. At the time the Japanese were very focused on subduing China, so that might just be enough for the Japs to leave Indochina alone.

How long would that delay the embargo? And what might be the trigger to TTL's embargo?
 
How long would that delay the embargo? And what might be the trigger to TTL's embargo?

The war was still underway in China, and that remained deeply unpopular in the U.S..

But without Indochina's occupation, I expect you might see a much more modest and gradual increase of sanctions or trade restrictions by FDR. Japan might take longer to reach a pain threshold. But in the meantime, the U.S. is already deep into its military buildup.
 
Simple, two part question: could Pearl Harbor have been delayed? If so how long?

Possibly. I came up with a scenario.

In mid-1941, someone in the State Department overreaches regarding U.S. commitments in the Pacific to Britain and the Netherlands. The resulting hooraw endangers Lend-Lease and the draft extension. FDR has to disclaim such commitments, and lacking explicit U.S. support, the Dutch withdraw from the oil embargo against Japan.

With the embargo broken, Japan cancels the "Southern Operation" and therefore the Pearl Harbor attack as well. Also, some Japanese suggest taking advantage of the apparent Soviet collapse in the face of BARBAROSSA, but nothing comes of it.

After a few months, the hooraw in the U.S. dies down and the Dutch are persuaded to rejoin the oil embargo. Japan resumes its march to war, and the Pacific War opens as OTL, but several months later.
 
Last edited:
Top