Japanese accumulation of experience in the Pacific

[Alan Meyer]

One aspect of the Pacific theater of war that seems to me
different from all other theaters is the nature of the experience
gained (or not gained) by Japanese forces.

It appears to me that, in most of the island battles, especially
after Guadalcanal, all of the Japanese forces and all of their
officers were killed or captured. It would therefore seem that,
in every subsequent battle, the Americans gained more and more
experience but the Japanese would all be essentially
inexperienced. Some might have had limited experience in the
Philippines or New Guinea, but none would have had experience
with fighting against the Marine Corps or the increasingly
powerful naval and air forces that dominated sea and sky.

Do you think this played a role in Japanese defeats? Or did they
overcome this lack of direct experience by reading radio reports
from the forces that were later overwhelmed in previous battles?

Clearly, Japanese strategy did evolve, from fighting at the
water's edge to fighting instead from the best mountain
positions, and from digging in, to digging in really deep with
defenses in great depth. Clearly, they learned that victory in
the sense of holding the island was impossible and that all of
them were going to die. But that's a pretty depressing kind of
"experience" and it doesn't necessarily lead to better tactics.

Alan

[news]

Post by Alan Meyer
One aspect of the Pacific theater of war that seems to me
different from all other theaters is the nature of the experience
gained (or not gained) by Japanese forces.
It appears to me that, in most of the island battles, especially
after Guadalcanal, all of the Japanese forces and all of their
officers were killed or captured. It would therefore seem that,
in every subsequent battle, the Americans gained more and more
experience but the Japanese would all be essentially
inexperienced. Some might have had limited experience in the
Philippines or New Guinea, but none would have had experience
with fighting against the Marine Corps or the increasingly
powerful naval and air forces that dominated sea and sky.
Do you think this played a role in Japanese defeats? Or did they
overcome this lack of direct experience by reading radio reports
from the forces that were later overwhelmed in previous battles?
Clearly, Japanese strategy did evolve, from fighting at the
water's edge to fighting instead from the best mountain
positions, and from digging in, to digging in really deep with
defenses in great depth. Clearly, they learned that victory in
the sense of holding the island was impossible and that all of
them were going to die. But that's a pretty depressing kind of
"experience" and it doesn't necessarily lead to better tactics.
Alan

Apparently they learned something as the tactics changed in the
Philippines and Okinawa

[SolomonW]

Post by Alan Meyer
Clearly, Japanese strategy did evolve, from fighting at the
water's edge to fighting instead from the best mountain
positions, and from digging in, to digging in really deep with
defenses in great depth. Clearly, they learned that victory in
the sense of holding the island was impossible and that all of
them were going to die. But that's a pretty depressing kind of
"experience" and it doesn't necessarily lead to better tactics.

On this topic, I hope you find this interesting. Is results are quite
different to yours.

At work, I am doing a lot of data mining, so I decided to try to see what I
could find if I did some WW2 figures. What I did was go through the
Japanese US battles in WW2, using data from the Wikipedia. Some of the
figures are a bit dubious, for example, Japanese laborers are sometimes
listed as soldiers. Still, I did my best. Furthermore, let me say I am
aware that on Allied side, there were often troops from other countries
besides the US and similarly, there were troops from other countries,
mainly Korea on the Japanese side.

Some of my conclusions from this study are quite surprising.

The period I examined was the Island hopping campaign by the US in the
Pacific against Japan from late 1943 to 1945. Some of these but not all
were extremely one-sided conflicts with many times more American troops
than Japanese. As well, the Americans had both air and naval superiority
plus better and more equipment on the ground. All these advantages improved
over time. Plus over time, more and more Japanese soldiers would surrender
so signifying a drop in Japanese military determination.



Here is a table of the US Island hopping campaign from 1943 to 1945.
Battle, Start,Day No, Days, US, US-dead,
Japan, Japan-dead
Battle, Start, D3, E3, F3, G3,
H3, I3,
Battle of Tarawa ,20/11/1943, 713, 4, 35000,
1009 ,4819, 4673
Battle of Kwajalein ,31/01/1944 ,785 ,4 ,42000
,372 ,8100 ,7870
Battle of Saipan ,15/06/1944 ,921 ,25 ,71000
,2949 ,31000 ,29000
Second Battle of Guam ,21/07/1944 ,957 ,21
,36000 ,1747 ,22000 ,18040
Battle of Tinian ,24/07/1944 ,960 ,9 ,30000
,328 ,8810 ,8010
Battle of Peleliu ,15/09/1944 ,1013 ,74 ,10994
,1794 ,11000 ,10695
Battle of Angaur ,17/09/1944 ,1015 ,14 ,15000
,260 ,1400 ,1338
Battle of Luzo ,9/01/1945 ,1129 ,219 ,175000
,8310 ,250000 ,205535
Battle of Iwo Jima ,19/02/1945 ,1170 ,36 ,70000
,6812 ,22060 ,21844
The Battle of Okinawa ,1/04/1945 ,1211 ,82
,183000 ,12513 ,117000 ,100000


As I used excel, for my variables, I used excel conventions.
D3=Number of days since Pearl Harbor
E3=days the battle raged.
F3=US attacking force
G3=US dead, it may include air force too. I am not sure what the wiki uses
H3=Japanese original defending force.
I3=Japanese dead.

The totals were on this table
E3=488
F3=667994
G3=36094
H3=476189
I3=407005

Please bear with me, as I think, it will be interesting.

I am trying to measure E3 in terms of D3, F3 and H3 so the formula my
computer program came up with were.

E3=32.76+0.001234*H3 + 4.372*TAN(D3) - 0.0007463*F3 - 10.57*SIN(5.776 + F3)

So plugging these values into these equations, I have

Battle, E3
Battle of Tarawa ,3
Battle of Kwajalein ,5
Battle of Saipan ,26
Second Battle of Guam ,22
Battle of Tinian ,8
Battle of Peleliu ,74
Battle of Angaur ,14
Battle of Luzo ,219
Battle of Iwo Jima ,36
The Battle of Okinawa ,82

The totals on this table is
E3=488 days

Which is almost spot on to what the actual figures were.

What I then decided to do was change the dates of the battles.

So I asked the computer let us assume that all battles took place on
20/11/1943. What would be the result. The total of
E3=403 Days

As you see the Japanese in this model fought less days

So I asked the computer let us assume that all battles took place on
1/04/1945, the day of the Battle of Okinawa which was seen as a dress
rehearsal for the invasion of Japan. Now the result was now.

E3=928 Days

As you see the Japanese in this model fought more days with the same
resources.

The Japanese strategic plan during this period was to hold off the American
advance and this model suggest that they were getting better at it.

This would lend weight to those that argue that the invasion of Japan was
not going to be quick as some suggest.


For a previous discussion on this analysis follow the links below.


https://groups.google.com/forum/#!searchin/soc.history.what-if/data$20mining/soc.history.what-if/PFH-Dkxxmrs/SuKMygaZve4J

[Roman W]

Post by SolomonW
D3=Number of days since Pearl Harbor
E3=days the battle raged.
F3=US attacking force
H3=Japanese original defending force.I

[...]

Post by SolomonW
I am trying to measure E3 in terms of D3, F3 and H3 so the formula my
computer program came up with were.
E3=32.76+0.001234*H3 + 4.372*TAN(D3) - 0.0007463*F3 -

10.57*SIN(5.776 + F3)

I like your idea in general, but the sine function at the end of the
formula doesn't look too convincing. It's oscillating pretty rapidly
-adding 3 soldiers to F3 will change E3 by more than 10 days! I don't
think that makes sense at all. What results would you get if you just
dropped the last term? Or maybe simplified the problem even further
and just used polynomials?

RW

[SolomonW]

Post by SolomonW

Post by SolomonW
D3=Number of days since Pearl Harbor
E3=days the battle raged.
F3=US attacking force
H3=Japanese original defending force.I

[...]

Post by SolomonW
I am trying to measure E3 in terms of D3, F3 and H3 so the formula

my

Post by SolomonW
computer program came up with were.
E3=32.76+0.001234*H3 + 4.372*TAN(D3) - 0.0007463*F3 -

10.57*SIN(5.776 + F3)
I like your idea in general, but the sine function at the end of the
formula doesn't look too convincing. It's oscillating pretty rapidly
-adding 3 soldiers to F3 will change E3 by more than 10 days! I don't
think that makes sense at all. What results would you get if you just
dropped the last term? Or maybe simplified the problem even further
and just used polynomials?
RW

After testing about 2.7e10 equations without sin, my data mining program
gives the following equations for your selection.


E3 = 51.283480406238 + 5.55193138883655e-6*D3*I3 + 3.39223037536676e-7*I3^2
+ 5.66340900734232e-8*F3^2 - 0.00231905220538405*F3 -
1.43645614751856e-7*F3*I3 - 2.20925892576489e-7*H3*I3 -
1.32003694405011e-6*D3*F3"

E3 = 10.7399885043705 + 0.0180395880252847*G3 + 5342.38834349644/D3 +
7.55087817353894e-6*G3*I3 - 0.000234680564277943*F3 -
1.02854865697795e-6*F3*G3 - 4.66208993900769e-6*G3*H3 -
3.83698828661509e-8*I3^2"


E3 = 23.9897153291653 + 0.018041370717457*G3 + 7.53963941077588e-6*G3*I3 -
0.000246034567027339*F3 - 0.00770406863317074*D3 -
1.02355419823735e-6*F3*G3 - 4.66019825207213e-6*G3*H3 -
3.81295041952582e-8*I3^2"


E3 = 0.037830834312887*D3 + 0.0265538213077078*G3 + 0.00949982820894988*I3
+ 1.68006155988452e-6*G3*I3 - 29.0025407142753 - 0.008732536795351*H3 -
8.57969206974965e-7*F3*G3 - 3.32970043596259e-8*I3^2"


E3 = 12.1124702265708 + 0.02071850361579*G3 + 7.70298397495148e-6*G3*I3 -
0.000415988230766421*I3 - 1.12829574769473e-6*F3*G3 -
4.63393688142679e-6*G3*H3 - 4.18661047649325e-8*I3^2"

E3 = 45.6676921070655 + 0.0144643471658339*I3 + 2.54024576918049e-6*G3^2 -
0.00351204051121849*G3 - 0.00883425301519471*H3 - 1.12332027616894e-7*G3*H3
- 2.5515858820985e-6*D3*F3"


E3 = 43.4206794317311 + 0.0144025686744957*I3 + 1.70350940637524e-9*D3*G3^2
- 0.00907864795046112*H3 - 9.66924846638433e-8*G3*I3 -
2.44313004790422e-6*D3*F3"

E3 = 44.2703885135648 + 0.0137246107104491*I3 + 2.04157745847373e-6*G3^2 -
0.00867754466647733*H3 - 8.05508408477337e-8*G3*I3 -
2.42991726961044e-6*D3*F3"

E3 = 0.00336244737726983*I3 + (214742.822250486*I3 +
260.799265884647*G3*I3)/(F3*H3) - 0.000447679891492826*F3 -
0.00161994282778319*H3"

E3 = 24.4680432053009 + 0.00756461902736677*I3 + (70346.4027856989 +
0.0179887119388336*G3*I3)/F3 - 0.00102284659669621*F3 -
0.0054293714196895*H3"

E3 = 28.9188778878657 + 0.00735987469522605*I3 +
0.0196690412048978*G3*I3/F3 - 0.00108024443762079*F3 -
0.00530210970726009*H3"

Note the excercise is a a bit dubious as there are less then 30 data points
which is a min I would accept at work. Also many of the values, I used are
the best available and as I pointed out are dubious.

Still what is interesting is D3 which is the Number of days since Pearl
Harbor is a fairly minor factor. So if one accepts that the US military
were getting better over time, this only makes sense here if one assumes
that the Japanese were also getting better.

[GFH]

Post by Alan Meyer
One aspect of the Pacific theater of war that seems to me
different from all other theaters is the nature of the experience
gained (or not gained) by Japanese forces.
It appears to me that, in most of the island battles, especially
after Guadalcanal, all of the Japanese forces and all of their
officers were killed or captured. It would therefore seem that,
in every subsequent battle, the Americans gained more and more
experience but the Japanese would all be essentially
inexperienced. Some might have had limited experience in the
Philippines or New Guinea, but none would have had experience
with fighting against the Marine Corps or the increasingly
powerful naval and air forces that dominated sea and sky.
Do you think this played a role in Japanese defeats? Or did they
overcome this lack of direct experience by reading radio reports
from the forces that were later overwhelmed in previous battles?
Clearly, Japanese strategy did evolve, from fighting at the
water's edge to fighting instead from the best mountain
positions, and from digging in, to digging in really deep with
defenses in great depth. Clearly, they learned that victory in
the sense of holding the island was impossible and that all of
them were going to die. But that's a pretty depressing kind of
"experience" and it doesn't necessarily lead to better tactics.

It is wrong to assume that the Japanese troops that
the US met were universal truths for the Japanese.
Consider Burma. Consider the Three Weeks War between
the USSR and the Japanese. Japanese do not surrender?
The USSR took 670K PoWs. Could it be that the US
did not take Japanese PoWs? Not surprising. Taking
prisoners while on patrol in the jungle is not going
to happen, unless the purpose of the patrol is to
take an enemy for interrogation. (Which means men
specifically assigned to holding one or just a few
PoWs.)

GFH

[WJHopwood]

..... Clearly, Japanese strategy did evolve, from fighting at the
water's edge... to digging in really deep with defenses in great
depth. Clearly, they learned that victory in the sense of holding
the island was impossible and that all of them were going to die..

... Japanese do not surrender? The USSR took 670K PoWs. Could it
be that the US did not take Japanese PoWs?

An interesting question. A good friend of mine, Ralph Walker-Willis,
was a Marine Sergeant among those in the fourth wave ashore at Iwo
Jima and was in combat on Iwo for 30 days. Years later he wrote
in his memoir, "My Life as a Jarhead," that the taking of Japanese POWs
was given little thought before or during the battle. Early on, the
Japanese General must certainly have known he couldn't win. Had he
surrendered to the inevitable, Willis said, thousands of lives on both
sides could have been saved.
On the night before the assault, Willis wrote, his unit was gathered
together on the troopship and briefed by their CO on details of their
mission and what they might expect. During a QandA after the briefing
one Marine asked, "What about prisoners?" The answer he received was
short. "We don't want any."
Who knows if this was just the unofficial word of one CO, or
whether something like it was passed down to other units by other COs,
or if "we don't want any" was just "assumed" by the marines about to do
the fighting? My guess is maybe "all of the above."

WJH

[Geoffrey Sinclair]

Post by GFH
It is wrong to assume that the Japanese troops that
the US met were universal truths for the Japanese.
Consider Burma.

Quite regular IJA soldiers, even in 1944 allied troops record
recovering men who had been captured by the Japanese and
used as bayonet targets.

In 1945 the Japanese supply lines broke down which helped
up the prisoner count. Then came the surrender.

Post by GFH
Consider the Three Weeks War between
the USSR and the Japanese. Japanese do not surrender?
The USSR took 670K PoWs.

Or more other estimates have higher numbers. The troops were
largely green recently raised, plus lots of rear area troops, the
fighting went on after the Emperor's speech and of course then
there was the surrender.

Post by GFH
Could it be that the US
did not take Japanese PoWs?

They took a number of them.

Post by GFH
Not surprising. Taking
prisoners while on patrol in the jungle is not going
to happen, unless the purpose of the patrol is to
take an enemy for interrogation. (Which means men
specifically assigned to holding one or just a few
PoWs.)

Let us see now, the Japanese troops in the Pacific tended to
be the pre war regulars, the ones that committed suicide
rather than be captured, the ones that feigned death in the
hope of killing and being killed, similar for surrender. Let us
not forget the killing of Japanese wounded rather than let them
fall into allied hands. Add many Japanese troops though they
would be killed anyway, sailors refusing rescue, pilots flying
without parachutes.

Try the Japanese civilians on Saipan committing suicide, and
the fact the fanatics amongst the soldiers and civilians upped
the death rates by killing or pressuring those not willing to die.

See the Japanese behaviour in the mass breakout at Cowra
on 5 August 1944, the number who committed suicide in the
barracks or after escaping from the camp.

Most early men taken prisoner did so while unable to do anything
about it. See for example the survivor of the midget submarine
attack on Pearl Harbor.

By the war George you are aware of the prisoner take on Okinawa?
Somewhere around 7,400, the first time the Japanese actually
surrendered in "large" numbers. The fanaticism was beginning
to fall away.

There were 52 Japanese prisoners in the US as of December
1942, 112 a year later, 2,929 in December 1944 and 5,413
in August 1945. Most early Japanese PoWs were put into
camps in Australia and New Zealand.

By August 1944 the Australians were holding around 2,200
Japanese prisoners. By August 1945 that was up to 121
officers and 5,127 other ranks, these included 546 merchant
seaman and 3,779 captured by American forces.

Geoffrey Sinclair
Remove the nb for email.

[Alan Meyer]

Post by GFH
It is wrong to assume that the Japanese troops that
the US met were universal truths for the Japanese.
Consider Burma.

I'm not sure what you want to say about Burma. However it is
true, contrary to my original thesis, that the Japanese did gain
some experience of war against the Allies there and so were able
to do some learning. However, I'm not sure that lessons learned
in Burma applied to the Pacific islands, or that leaders of
Japanese forces in Burma played any role in planning the island
defenses.

Post by GFH
Consider the Three Weeks War between
the USSR and the Japanese. Japanese do not surrender?
The USSR took 670K PoWs.

I believe that the POW's in Manchuria were taken after the
Japanese surrender. That's a different story. But even after
the official surrender some Japanese fought on and some Japanese
civilians committed suicide or were killed by Japanese troops in
order to avoid surrender.

Post by GFH
Could it be that the US
did not take Japanese PoWs? Not surprising. Taking
prisoners while on patrol in the jungle is not going
to happen, unless the purpose of the patrol is to
take an enemy for interrogation. (Which means men
specifically assigned to holding one or just a few
PoWs.)

Agreed. Warfare on the islands tended to be all out with no
quarter given on either side. There are numbers of American
accounts confirming this.

However we also know that there were major attempts to take
prisoners. For example, Japanese speaking Americans were
employed in calling Japanese out from their caves. I believe
there ware also cases of aerial pamphlet and loudspeaker
announcements aimed at inducing surrender and providing ways to
do it without getting shot.

These were situations in which resistance was futile and yet,
until the last battles of the Pacific, surrenders were very, very
few. The Japanese ratio of fighting to the death as compared to
surrender was way higher than that in any other army in any other
theater of the war.

That's a different phenomenon from bitter jungle warfare.
Americans DID surrender in such circumstances - on Wake, Guam,
and the Philippines. British surrendered in Malaya and
Singapore. Japanese did not surrender in analogous situations
until the end of the war.

Alan

[news]

Post by GFH
It is wrong to assume that the Japanese troops that
the US met were universal truths for the Japanese.
Consider Burma. Consider the Three Weeks War between
the USSR and the Japanese. Japanese do not surrender?
The USSR took 670K PoWs. Could it be that the US
did not take Japanese PoWs?

I think we were all raised with the understanding that the Japanese were
determined to fight to the death for their emperor and that surrender
was morally unacceptable. The author of the book Fly Boys wrote about
there were several instances of Japanese fulling a fast one on their
captors and the reaction of the American troops was not to take any
chances. Their resources were stretched thin and they were not prepared
to take the risk, so they just didn't take prisoners,





Dave Smith

[Bill]

On Tue, 01 Apr 2014 10:39:48 -0400, "news"

Post by news

Post by GFH
It is wrong to assume that the Japanese troops that
the US met were universal truths for the Japanese.
Consider Burma. Consider the Three Weeks War between
the USSR and the Japanese. Japanese do not surrender?
The USSR took 670K PoWs. Could it be that the US
did not take Japanese PoWs?

I think we were all raised with the understanding that the Japanese were
determined to fight to the death for their emperor and that surrender
was morally unacceptable. The author of the book Fly Boys wrote about
there were several instances of Japanese fulling a fast one on their
captors and the reaction of the American troops was not to take any
chances. Their resources were stretched thin and they were not prepared
to take the risk, so they just didn't take prisoners,

Not just American troops, the British in India and Burma tended to
'make sure' of any Japanese bodies lying around and took remarkably
few prisoners until the final advance to Rangoon.

[Paul F Austin]

Post by Bill
On Tue, 01 Apr 2014 10:39:48 -0400, "news"

Post by news

Post by GFH
It is wrong to assume that the Japanese troops that
the US met were universal truths for the Japanese.
Consider Burma. Consider the Three Weeks War between
the USSR and the Japanese. Japanese do not surrender?
The USSR took 670K PoWs. Could it be that the US
did not take Japanese PoWs?

I think we were all raised with the understanding that the Japanese were
determined to fight to the death for their emperor and that surrender
was morally unacceptable. The author of the book Fly Boys wrote about
there were several instances of Japanese fulling a fast one on their
captors and the reaction of the American troops was not to take any
chances. Their resources were stretched thin and they were not prepared
to take the risk, so they just didn't take prisoners,

Not just American troops, the British in India and Burma tended to
'make sure' of any Japanese bodies lying around and took remarkably
few prisoners until the final advance to Rangoon.

It took only a tiny number (and the number _wasn't_ tiny_) of renegade
surrenders before "take no prisoners" became the rule. In the best of
times, negotiating surrender on the battlefield is very dicy, much safer
to wait until after the battle has passed by.

While the Japanese systematically violated the law of land warfare and
the Geneva Convention on the treatment of prisoners, after Guadalcanal,
the Japanese were completely dehumanized in the eyes of the American
troops. Paul Fussell talks about American troops hunting gold teeth
among Japanese dead and preparing and sending Japanese skulls home to
their families.

Paul

[Roman W]

On Wed, 02 Apr 2014 10:39:14 -0400, Paul F Austin

Post by Paul F Austin
troops. Paul Fussell talks about American troops hunting gold teeth
among Japanese dead and preparing and sending Japanese skulls home to
their families.

It says as much about the Americans as about the Japanese.

RW

[Rich Rostrom]

Post by Bill
Not just American troops, the British in India and Burma tended to
'make sure' of any Japanese bodies lying around and took remarkably
few prisoners until the final advance to Rangoon.

George MacDonald Fraser in _Quartered Safe
Out Here_ wrote of an incident when a lot
of wounded Japanese prisoners were left
overnight under guard by Indian Army troops.

In the morning, the Japanese had all been
thrown in a handy trench and buried under
sacks of cement.

[David Wilma]

I was puzzled about this too. In Bradley's Flags of Our Fathers
the Japanese on Iwo Jima knew a lot about the marines
including the signature equipment bags of Navy corpsmen.
Defenders were alerted that the bags marked critical members
of Marine units and to target them. How did the Japanese
know that if all the other defenders on other islands were
killed or captured?

[PatrikH]

Post by David Wilma
How did the Japanese
know that if all the other defenders on other islands were
killed or captured?

On occasion the Japanese evacuated troops, for example more than 10000 from Guadalcanal alone. On top of that you have radio and courier messages by submarine.

[Chris Allen]

Alan Meyer wrote:>

Post by Alan Meyer
Clearly, Japanese strategy did evolve, from fighting at the
water's edge to fighting instead from the best mountain
positions, and from digging in, to digging in really deep with
defenses in great depth.

This observations suggests the "change in stratergy" was all due to
different notions about the best way to defend an island.

I suspect topography and time to buid may be just as important.

I understand the island of Tarawa, one of the first to be recaptured, is
small and very flat. No chance of fighting from a fortified mountain top.

As island hopping continued, the islands themselves generally had more
in the way of "mountains" to fortify. They were closer to Japan for
supply of building material. They also had more time to fortify them
because it took longer for allies to get there.