Pearl Harbor, 7th December 1939.....

[Night Fighter Nut]

As I remember, the Japanese always wanted to perform any negotiations from a position of strength. One of the major reasons they didn't surrender when they already knew the war was lost. I believe the Japanese, at the end of the war, wanted to have at least one major victory before discussing terms or surrender in order to save face. So the senario of only taking the major ports and holding them as a barganing chip for keeping other holdings in the Pacific makes sense.

 

[Night Fighter Nut]

As for the defense of Oahu, I was stationed there for three years as part of the 25th Infantry Division (Light) and have walked all over that island and several others as well as part of military exercises (ie. war games). I was a light infantryman for several years and I have had the chance to work with the Japanese army in a joint exercise called Yamasakura in I think was '85 or '86. Having said that, I am very familiar with the defenses of those islands both historical and present because I have physically seen them. Before any attack, the Japanese plan their actions well in advance and take into account as many possiblities as can be dreamed up and plan counter measures for them. They would have spies watching the fleet's movements as they did before the Pearl Harbor attack. An agressor such as the Japanese in this made up scenario would have the benefit of prior planning and counter planning taking into account the situation they faced before engaging. To suggest that they would just run off and do something without planning is not Japanese thinking. Knowing Oahu's defenses as I do, it is very possible for a large force to hit hard and fast and take the island. In fact it is believed by those who lived there, and I have talked to them, that had the Japanese had an invading force with them, they could very well have taken all the islands.

 

[Shinpachi]

Hello, Night Fighter Nut.
Your experience in Hawaii is very precious and looks fantastic.

Anyway, it was impossible for Japan to attack Pearl Harbour in Dec 1939 as the idea was only stated in Yamamoto's brains and it was not until September 1941 that IJN began discussion about the plan.
Majority was insisting to draw the US fleet closer to Japan to attack. Also IJN fleet was to return to Japan on Dec 5, 1941 if the diplomatic negotiation in Washington might have resulted well.

Sorry. This may have nothing to do with the theme but I am convinced that Japan will never attack Pearl Harbour again. Recently I can't identify who is a Japanese or not. See
View: https://www.youtube.com/watch?v=SJXyQbv-_W0

Thanks.

 

[Night Fighter Nut]

Sorry. This may have nothing to do with the theme but I am convinced that Japan will never attack Pearl Harbour again. Recently I can't identify who is a Japanese or not. See
View: https://www.youtube.com/watch?v=SJXyQbv-_W0

Thanks.

Greetings Shinpachi san, no need to feel sorry. Our thread is only to discuss the what if's and is pure fantasy. A kind of mental exercise to determine the possible outcomes based on what we know. All very friendly and your point of view would be most appreciated.

 

[Shinpachi]

I was afraid of my post being understood wrongly but you have caught it correctly.
Thanks Night Fighter Nut!
I respect your charity relationship in Osaka

 

[Night Fighter Nut]

Thank you Shinpachi san. Here is a link to the history of the Holy Family Home in Osaka incase you are interested.

Holy Family Home

I think it refers to a book call, "A bridge of love from east to west." These books are rare but fortunately I have one of them.

 

[parsifal]

I agree that the chances of a japanese attack on the US in 1939 were basically nil, but the question arose from the assumption that Japan did attack at that time. Ehat would be the possibilities. Then people started to anticipate a predictable path of attack for the japanese and did not consider the possibilities of a direct attack on the US. They still believe it to be impossible, and likely to not even get off the ground.

I disagree. But I do think it would end badly, unless the Japanese were able to achieve some sort of negotiated peace that gave them a freer hand in the Far East....a sort of "sudatenlandent" or "anschliss" on a massive scale.

Shin, NFN is completely correct, this is not intended as any sort of indictment of the Japanese, at least not from me, we are just exploring the strategic possibilities

 

[GrauGeist]

Agreed, this is a great "what if" that is exploring the possabilities, and I've enjoyed it so far.

I know I was the one that put up the scenario of the Japanese assisting the Germans in the Gibraltar assault "what if" scenario, but if you think about it, the history of warfare has been full of situations that came about by a chance decision or an unlikely event occuring that people of the time wouldn't have thought possable or logical.

 

[renrich]

Sys has made some cogent points about an invasion of the US west coast in 1939 by Japan and those points are why I don't believe the Japanese could do more than land a small force somewhere and that force would be annihilated, those that were not already drowned, by local military forces. Under those conditions it would be a mistake to underestimate the capability of the National Guard in the various states. Those guard units would be lightly armed but so would the Japanese forces. I have a topo map of the US on my wall and if an invasion force did effect a lodgment the physiographic features would all be in favor of the defense. The ground favored the defense in Italy and the ground in the western US makes Italy look benign.

 

[parsifal]

I dont agree with Sys's appraisal. He knows that to make the landing at normandy was against heavily defended beaches. He might not know that the Divisional slice for an allied Infantry Division was about three times that of a Japanese Infantry Division in 1939. In 1939 the heaviest Japanese Infantry Division had a Divisional slice of just under 20000 men, but one adapted for amphibious work had been pared down to under 15000 men. The divisional slice for an allied division attacking in Normandy after the landings was in excess of 55000 men, not including corps or army support assets that were regulalry attached.

By nightfall on June 6, more than 200,000 had made it ashore and secured French coastal villages. Within weeks, supplies were being unloaded at Utah and Omaha beachheads at the rate of more than 20,000 tons per day. By June 11, a further 526,000 troops, 55,000 vehicles, and 105,000 tons of supplies had been landed on the beaches. Thats just five days after the initial landings, without the benefit of any established port facilities. A key for this scenario would be the capture of a functioning port, much the same as the germans had to do in the norwegian campaign. In fact an invasion of the US west coast in 1939 has many similarities to the Norwegian situation, and the terrain far worse than anything in the US, I would expect.

I do not see any great similarity to the Italian campaign, where the German opposition amounted to the order of 15-20 divs. In this scenario, the Americans could possibly call on two regular Divs, perhaps some marine assets, a limited number of National Guardsman (after the invasion) and some months after that, some irregular formations. Against that they would be up against more than 0.5-1 million battle hardened veterans which in turn has access to more shipping than was allocated to supporting the Normandy campaign. And Normandy was an operation where the fighting was against around 70 enemy divs, and the fighting intensity (and hence ammunition expenditure) proportional to the size of that campaign. In this hypothetical the logistic demands despite the large numbers of troops would be a fraction of that....l

The difference between Norway and US'39 is the distances needed to make the landing. The Japanese however demonstrated their ability to make landings on a large scale at moderate distances from their home ports in the opening days of WWII, brushing aside with ease even regular formations that resisted them. The question for me is, if they were given the ability to concentrate all their shipping to support a continental invasion against virtually no landward opposition, could they pull it off. I think that they could. The japanese incidentally compared to a 1939 US Infantry Division, were not "lightly armed". The principal firepower of an Infantry Div is its artillery, statistically generating well over 60% of the total enemy casualties . In 1939 the principal artillery pieces in both armies were 105 and 75 mm artillery pieces, but the Japanese had an extra battalion of guns attached, 36 to 24, and in addition they had fully integrated their artillery support guns directly into their battalions, adding a total of a further 18 artillery pieces to their gun parks. The Japanese in 1939 were not "lightly armed". They were in fact more comprehensively equipped than the US army at that time. The big reorganizations of the US army did not begin until 1940-41 .

At sea, the USN may have offered resistance, but judging by what happened to them in the immediate days of Pearl Harbour, this is unlikley to go well for them. IN fact, there is no reason to prevent tha Japanese from pulling off a Pearl Harbour style attack into San Diego itself. If the US carriers are caught whilst in Harbour, the US would be in a mess of hurt. If Panama was to be captured (and at that time there was less than a battalion defending it, the Atlantic Fleet would be weeks, if not months away from entering the battle. If all the ports on the west coast were captured, along with Pearl itself, the USN would be forced to operate from the periphery of the battle, from Dutch Harbour, or American Samoa, both of which would have been totally inadequate for a sustained campaign

Its interesting to compare the equipment of the two air arms at that time. The Japanese would be equipped with A5Ms , D3A Vals and B5N Kates. The US had two squadrons of F2As (but these were grounded in 1939 following undercarriage problems, F3Fs, Sb2Us and TBDs. The Fighters in both navies were relatively inneffective compared to the wildcat/zero fighters of 1941, and the US strike aircraft relatively more vulnerable due to their low speeds. Neither side had any armour protection or self sealing tanks, and radios would have been somewhat of a novelty. There were no fast american battleships, which reduces the US fleet speeds to under 20 knots. I dont know where this idea that invasion convoys approach at 5-10 knots....Japanese amphib convoys had a typical approach speed of around 15 knots, making them a difficult target for the US BBs to intercept.

 

[Night Fighter Nut]

As I recall, American naval aircraft had a much shorter range than Japanese naval aircraft. I think this may also have a limiting effect on American striking ability.

For an offensive to be successful you have to have at least one of two things in your favor. One is momentum, the other is numbers. In the initial stages of an assualt, be it beach or otherwise, communication is essential. Should the Japanese say strike in the early hours of morning on a surprise attack. Initial communications would be fast and incoherent because of panic. The standard rule of a commander is not to believe the first reports because they are always wrong. This is still practiced today. A good defense, if prepared in advance, has an initial force manning the front line with a mobile reserve force to throw in once its knows where the main force of the attack is or should some point of the defense start to crumble. The initial confussion would delay the movement of any counter force and if the attacking momentum isn't halted the front line would be very hard pressed to hold. Most defenses at that time were run along a line similar to trench warfare. Usually not very deep defensively. Once a section of that line is broken, the attackers file through the hole and attack the other defenses from the side and rear. Granted that the rugged coastline favors the defenders.

With numbers you have a senario similar to the Normandy beach landing unless the attack is a complete surprise. Then it would be relatively easy to land a large force and establish a position to move inland from and secure key strategic points. Of course holding those positions is another matter.

 

[Night Fighter Nut]

Light infantry usually refers to assets the infantry unit itself posesses. Infantry units, as I recall, are named as regular, light, mechanized, or airborne. Each is defined by the assets that are organic to the unit. It doesn't mean they can't have other units attached to them. The can be a part of an armored force and still be called light.

 

[Shinpachi]

Thanks Night Fighter Nut, parsifal and GG for your care.
I understand this place is to enjoy the what-ifs but the assumption seemed less realistic to enjoy as if what if Japan had atomic bombs prior to US.

I would rather be interested in how Japan-US could have avoided the war.
Thanks again for your great assisstances and please take my apology if I may have disturbed you.

PS: I'll check the Holy Family Home again well. Thanks Night Fighter Nut for the information.

 

[Night Fighter Nut]

What could have been done to avoid the war? My thoughts would be better communication between countries. Hmmm. Ok guys, lets follow Shinpachi sans request and get our creative juices flowing. It seems so much easier to estimate what one could do in war, lets see what the possibilites are for waging all out peace. Options... Hmm. Usually in that time period there was either a mutual truce, non-agression pact, or peace through superior firepower. Shinpachi san, what was the likelyhood of the people requesting the Emperor to do something and the likelyhood that he would listen? Hipothetical of course. Also what do you think other countries could do to draw Japan into dialog?

 

[Night Fighter Nut]

Still, what could Japan do to draw other countries into dialog?

 

[parsifal]

Avoiding war with Japan in the preWWII environment would have been very difficult. The Japanese government was militaristic and expansionist, and pursuing policies of closed door economic and political "spheres of influence. The US government was far more liberal and was supporting an open door free market economy, with little or no interest in overseas politics. The two ideologies were mutually exclusive, and on a pathway to collision for a long time prior to the war.


In order to avoid war, the US would have needed to adopt a fundamentally different approach to Japan. Massive rearmamnt from about 1918, and direct interevention in China....meeting Japanese aggression head on with a massive retalitory response every time the Japanese stepped over the line. No signing of the Washington Naval Treaties. The Japanese would have been overwhelmed militarily and ultimately politically.

The chances of any of this happening are even more remote than the japanese invasion scenarios we are talking about

 

[renrich]

Micheal, your points about how to avoid a war with Japan are well made. The Japanese government lacked a fundamental understanding of the west and how they would react to Japanese aggression and what their capabilities were when they reacted.

Where we disagree on the invasion scenario is that I don't believe the Japanese in 1939 had the capability of putting a large force ashore on the west coast and supporting that force once ashore. A west coast invasion would bear some resemblance to Torch, in November, 1942. Torch was mounted by the Allies with a partnership between the British and Americans. The landings were made against lightly defended objectives. The big difference between Torch and the fantasy Japanese invasion is that Torch had almost complete mastery of the air and sea and their landing forces were much smaller than proposed in the Japanese fantasy and the distances involved were much, much smaller. Many other factors were present but, to me, the chances of a succesful invasion by a Japanese force large enough to be effective in 1939 were about the same as for the opposite event to take place, a successful invasion of Japan in 1939 by US forces.

 

[parsifal]

Micheal, your points about how to avoid a war with Japan are well made. The Japanese government lacked a fundamental understanding of the west and how they would react to Japanese aggression and what their capabilities were when they reacted.

Where we disagree on the invasion scenario is that I don't believe the Japanese in 1939 had the capability of putting a large force ashore on the west coast and supporting that force once ashore. A west coast invasion would bear some resemblance to Torch, in November, 1942. Torch was mounted by the Allies with a partnership between the British and Americans. The landings were made against lightly defended objectives. The big difference between Torch and the fantasy Japanese invasion is that Torch had almost complete mastery of the air and sea and their landing forces were much smaller than proposed in the Japanese fantasy and the distances involved were much, much smaller. Many other factors were present but, to me, the chances of a succesful invasion by a Japanese force large enough to be effective in 1939 were about the same as for the opposite event to take place, a successful invasion of Japan in 1939 by US forces.

I'll concede this...against a well defended beach defence, such as those that existed at norandy, the Japanese stood little or no chance. They did not develop amphibious technique to near the same degree as the Allies, and would have struggled against well defended targets. However, against lightly defended, or poorly defended targets the Japanese were as proficient as the allies, if not better, because their basic Infantry units in 1939-43 were better trained and organized with organically generated firepower so that they could operate more or less autonomously once ashore. this was a feature lacking in allied formations until the end of the war.

To make this fantasy scenario work, the Japanese need to have shipping, lots of it, and surprise. If either of these two ingredients are missing, the mission would fail. But if they managed to get ashore in numbers, and with reasonable supply to back them up, the US land forces are simply not strong enough or well organized enough to resist them effectively.

As for the US being able to do the same in reverse....possibly, but have not looked at the details sufficiently to say for sure.

 

[syscom3]

The Japanese have the distinction of having the only two amphib operations in the Pacific to have been thrown back to the sea in abject failure. Wake Island and Bataan.

Now lets play fantasyland and say that 20 Japanese light divisions did get ashore on the west coast. There are only three worth while places to attack. Southern Cal, San Fran and Seattle. Which one are you going to take, because the others are several hundred miles away from each other. How are your forces going to operate over those distances that were in 1939, only really accessible by train?

Now you say you are going to split your forces? For what? Get defeated in detail as the US industrial might gets mobilized?

Light infantry you say? Well, the IJA was never known for being mechanized like the Allies and Germans were. For all practical purposes, there isnt enough industrial capacity in Japan to build the numbers of tanks (all of which were horrible designs) and trucks to do the task at hand.

You are going to march eastwards over trackless and waterless deserts through incredibly rough deserts. Then you are going to march through one of the great mountain ranges in the world only to find out you still need to go march several hundred miles through the great plains just to find out you need lots of boats to cross the Mississippi river. And all of this will happen without losses, or timetable upsets when the harsh realities of summer in the desert and winter in the mountains?

And of course, the US industrial power will not do anything for months at a time and the Japanese army will be quickly supplied and reinforced by sea from bases 4000 miles away?

 

[parsifal]

The Japanese have the distinction of having the only two amphib operations in the Pacific to have been thrown back to the sea in abject failure. Wake Island and Bataan.

You should also add Milne Bay. There were several rather small affairs on Saipan and I think even Okinawa, all of which ended in failure. And for the allies there was the even bigger defeat at Dieppe and on the islands of Kos and one other that I forget now. The assaults on Iwo, Pellieu and Biak were all nasty affairs that by any objective analysis should be considered defeats. In Burma there were also several allied small scale amphib operation in the Arakan that were failures.

And lets not forget that the japanese undertook more amphibious operations with less troops, across a wider theatre of operations than any other nation in history

Now lets play fantasyland and say that 20 Japanese light divisions did get ashore on the west coast. There are only three worth while places to attack. Southern Cal, San Fran and Seattle. Which one are you going to take, because the others are several hundred miles away from each other. How are your forces going to operate over those distances that were in 1939, only really accessible by train?

Dont know, but i do know the Japanese were able to penetrate into the interior of China, with far worse terrain and far less infrastructure in 1937-38, with little difficulty. They were stopped in China by logistical difficulties and incresing levels of resistance by the Chinese, but only after having travelled approximately half the distance from the east coast to the west USA. I would say that the Japanese would have little diffulty in operating in the conditions that existed on the west coast USA in 1939, wher the levels of infrastructure were far more extensive, and the logistics far less demanding.

Now you say you are going to split your forces? For what? Get defeated in detail as the US industrial might gets mobilized?

Of course the Japanese have to split their forces If a Japanese Division is superior to a US Division in 1939, and the Americans have two divisions (unmobilized and not in position), and the Japanese are attacking with an assault force of say 6 Division, with another 14 following that, and they have the demonstrated and proven ability to operate in bad terrain and advance rapidly, what do you think they are going to do?

Light infantry you say? Well, the IJA was never known for being mechanized like the Allies and Germans were. For all practical purposes, there isnt enough industrial capacity in Japan to build the numbers of tanks (all of which were horrible designs) and trucks to do the task at hand.


Their tanks were not great, but in 1939 they were superior to anything available to the US Army. The best tank available to the US in 1939 was the M2, a predecessor to the Grant, minus the hull mounted gun. In the entire US there were the grand total of 18 of these tanks in existence in 1939, and there were no tanks actually in production until June 1940. To get even these grossly inferior vehicles off the production lines, with crews to man them and commanders to lead them would have taken more than a year to organize from the initial attack in December 1939.

Against this the Japanese had over 1500 tanks in total, all of which can be considered superior to the American Tank. These included the Type 89 (with a 57mm short barrelled gun, the Type 95 with a 37mm gun equal to the US machine in firepower. There were more than 100 Type 97s far superior to anything the US might hope to produce for at least two years). And there were hordes of tankettes and other AFVs all of which had proven useful in China, which at that time had formations better equipped than the US Army

Despite the low output of trucks that I agree with, the Japanese nevertheless managed to undertake major land based offensives, with very rapid rates of advance in Manchuria (in 1931), in China (1937-39, and again 1944-5), and also in Burma (1942). They wre the masters at improvisation and I do not see any great reason to suggest that this would not be repeated in this hypothetical...


You are going to march eastwards over trackless and waterless deserts through incredibly rough deserts. Then you are going to march through one of the great mountain ranges in the world only to find out you still need to go march several hundred miles through the great plains just to find out you need lots of boats to cross the Mississippi river. And all of this will happen without losses, or timetable upsets when the harsh realities of summer in the desert and winter in the mountains?

Err yes, I dont see the terrain in the US as being any more formidable than that faced by the Japanese in their advances in China in 1937-39, in Manchuria in 1931, in Burma in 1942, or perhaps most tellingly of all, across the Owen Stanley Mountains in 1942. The Japanese were not easily defeated by terrain, had the training the equipment and the organization to use their Infantry in such terrain, whilst carrying sufficient firepower at Battalion level to overpower most opposition they were likely to encounter in those conditions. In 1942, until their (ie the Japanese) supply ran out, AIF combat verterans had a hard time stopping them and this was done only after the Japanese, outnumbered and out of supply, had managed to advance to within 30 miles of Moresby. The Americans sent to fight them in the counteroffensive, were unable to cope with the Japanese at all, virtually falling apart as formations, despite having spent nearly a year in specialised jungle training. You might say the US was defeated by the terrain, but if, as you say the terrain on the west coast is that bad, I would think that would favour the Japanese rather than hinder them.

On the great plains, it would be more difficult, but again the japanese did demonstrate that they could handle even this type of warfare....remember your US formations are heavily outnumbered and lacking in mechanization in 1939, and the industrial capacity of the US is just not going to have much effect in the 3-6 months this campaign is occurring. It took the US economy more than two years to transform from a peacetime footing to a wartime economy, even with the massive injection of British Cash and carry funds to boost it along. In 1939 the US economy was sluggish and unresponsive, still recovering from the effects of the depression in many respects. I think the plains would be overcome by numbers....if we assume a month to overpower the coastal defences, occupy the ports and get them functioning, a month of fighting to cross the mountains, with say a loss of a division to both sides in this fighting, the Japanese are going to emerge from this battle with the equivalent of 29 divisions for the plains fighting to say 1.5 US regular Divs, say 3 National Guard units, and lets be generous say 2 Divs of these irregulars. As the Japanese this is a situation crying out for the standard Japanese Hook tactics, and as the American lines crack under this pressure, the rout begins with nowhere to hide....because we are on the plains remember......

And of course, the US industrial power will not do anything for months at a time and the Japanese army will be quickly supplied and reinforced by sea from bases 4000 miles away?

The Japanese were able to act more quickly than their opponents in 1941 when operating 2-3000 miles from their home bases, on mutiple fronts, and without the benefits of neutral shipping to support them. If the Japanese have neutral shipping to keep their domestic economy going, and can then concentrate their entire 6million tons of national shipping to the single front in this scenario, I actually think they would be better supplied than their scattered forces in 1941 could be. They demonstrated the speed that they could advance in China against stiffer oppositon than the US could put up in 1939, so why would I doubt their ability to advance quickly in this situation?????