Why was the Japanese Army's fatalities inflicted:suffered ratio so low in the Pacific theatre?

Question

Leaving aside the naval battles of the Pacific, why did the Japanese army do so poorly against allied forces (specifically United states and Australian forces) when on the defensive. While logistics and weight of numbers may indicate inevitable Allied victory in island battles, particularly later in the war, this does not explain why well embedded predominately high-morale troops with carefully designed defensive plans and structures almost always fared worse than invading forces.

While the Battle of Kaiapit is a great example of this, where Australia lost 14 men to over 200 Imperial: a disparity of losses is reflected in almost all areas of the Pacific theatre (except China) right through to (and including) the Battle of Okinawa.

What is the explanation for this? It was not as if the Imperial Army had not had ample training and experience, and while Japanese armour was weak and in short supply, artillery and gun emplacements are more important in defensive tactics (and these the Imperial army seemed to have plenty of).

Answer 1

Training and morale of Japanese soldiers

First of all, Japanese Forces were by no means inferior to their enemies in terms of fighting spirit or training. Beyond a doubt, No nation in WW2 had soldiers of such fanatical devotion in her service as Japan did, who actively sought out Gyokusai (Glorious death). Their mindset could be explained in Japanese martial song, Umi Yukaba:

If I go away to the sea, I shall be a corpse washed up. If I go away to the mountain, I shall be a corpse in the grass. But if I die for the Emperor, It will not be a regret.

Such was ferocity and fearlessness of the Imperial forces that it left the rivals bewildered for this was the sort of fighting they had neither experienced nor even imagined before.

This glorification of death reached such extremes that families of fallen soldiers were congratulated and normal mourning was considered shameful and inappropriate.

Among the recommended expressions to be offered to bereaved families were:

"Congratulations on his having achieved the honor of a death in battle"

"This occasion was really one of honor"

The bereaved were expected to respond with:

"Thanks to your kind concern he was able to achieve the honor of a death in battle. He certainly wanted this above all else. For us as family member it is enough that his death could repay the emperor's great beneficence."

Training of a Japanese soldier begain at school. The first text book a Japanese child was expected to study began with "Advance, Advance, Soldiers advance!".

The early victories and the spiral downwards

This sums up how early overwhelming victories of the Japanese were more relying on quality and training of Japanese soldiers, sailors and airmen rather than quality of their weapons. This is more credible as decline of Japanese might in the East can be traced back to Battle of Midway which resulted in loss of many veteran servicemen of Japanese forces, creating a shortage of similar calibered soldiers for future campaigns.

By mid-1942, the Japanese found themselves holding a vast area from the Indian Ocean to the Central Pacific, even though they lacked the resources to defend or sustain it. Rather than falling back to shorten the line of supply or consolidating the gains, the Japanese planned to expand even further which resulted in Battle of Midway. Japanese lost four carriers and one heavy cruiser, resulting in Japanese navy being on defensive stance afterwards. Loss in naval capability also meant that Japanese navy was no longer in a strong position to protect Island garrisons from Allied assaults or to completely secure routes for supply shipping to the garrisons. Which eventually resulted in the Isolation of Japanese strongholds and led to desperate actions as Allies began to by-pass unimportant island garrisons and blockaded them with submarines and air power with IJN being too weak to issue a proportionate response or to defend the isolated garrisons.

The Kill to Death ratio

The death to kill ratio in terms of infantry/other personnel was 8:5 in favor of Japanese, overall with 4,000,000 allied deaths as compared to 2,500,000 fallen Japanese. Elsewhere, the Allies fared much better than their Adversary. Following is an approximate overview:

╔══════════════════╦═══════╦════════╗
║                  ║ Japan ║ Allies ║
╠══════════════════╬═══════╬════════╣
║ Human Resources  ║ 5     ║ 8      ║
╠══════════════════╬═══════╬════════╣
║ Battleships      ║ 2.2   ║ 1      ║
╠══════════════════╬═══════╬════════╣
║ Aircraft Careers ║ 2.27  ║ 1      ║
╠══════════════════╬═══════╬════════╣
║ Cruisers         ║ 1.56  ║ 1      ║
╠══════════════════╬═══════╬════════╣
║ Destroyers       ║ 1.6   ║ 1      ║
╠══════════════════╬═══════╬════════╣
║ Submarines       ║ 2     ║ 1      ║
╠══════════════════╬═══════╬════════╣
║ Aircrafts        ║ 2     ║ 1      ║
╚══════════════════╩═══════╩════════╝

The key here is that above mentioned losses are over all Allied figures and do not reflect on the performance of the strongest Western Allies i.e US and UK. If we break down the figures by country then we get following results (KIA only, not including MIA, WIA):

Japanese Deaths:

Army

Note: Enemy here refers to the country which inflicted the stated number of losses on the IJA

╔═══════════════════════╦═════════╗
║         Enemy         ║   IJA   ║
╠═══════════════════════╬═════════╣
║ China ('37-'41)       ║ 185,647 ║
╠═══════════════════════╬═════════╣
║ China ('41-'45)       ║ 202,958 ║
╠═══════════════════════╬═════════╣
║ USA                   ║ 485,717 ║
╠═══════════════════════╬═════════╣
║ UK & Holland          ║ 208,026 ║
╠═══════════════════════╬═════════╣
║ Australia             ║ 199,511 ║
╠═══════════════════════╬═════════╣
║ French Vietnam        ║  2,803  ║
╠═══════════════════════╬═════════╣
║ USSR                  ║  7,483  ║
╠═══════════════════════╬═════════╣
║ Other KIA overseas    ║  23,388 ║
╠═══════════════════════╬═════════╣
║ POWs killed by allies ║ 380,000 ║
╚═══════════════════════╩═════════╝

Navy

╔════════════════════╦═════════╗
║                    ║   IJN   ║
╠════════════════════╬═════════╣
║ Military Personnel ║ 300,386 ║
╠════════════════════╬═════════╣
║ Civilian Personnel ║ 114,493 ║
╠════════════════════╬═════════╣
║ Overall            ║ 414,879 ║
╚════════════════════╩═════════╝

Allied Deaths

(POW Deaths Included)

╔═════════════════╦═════════════════════════════════════════════════════════════╗
║     Country     ║                            Losses                           ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ Australia       ║                            27,000                           ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ China           ║                         3.8 Million                         ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ British India   ║                            87,028                           ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ Britain         ║                            52,000                           ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ USA             ║                           111,914                           ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ Newzealand      ║                             578                             ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ the Netherlands ║                            9,400                            ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ Phillipines     ║                            27,000                           ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ France          ║                            <5000                            ║
╠═════════════════╬═════════════════════════════════════════════════════════════╣
║ USSR            ║ 12,031 (Not including Russo-Japanese border wars 1938-1939) ║
╚═════════════════╩═════════════════════════════════════════════════════════════╝

So as you can see, the bulk of Allied deaths were Chinese forces while other Allies did not lose near half as many men as China did.

Why the high causality rate?

The biggest factor in high casualty rate for Japanese was because of their Senjinkun military code based on "No-Surrender". Even when facing impossible odds, Japanese would rather kill themselves or launch suicide attacks than surrendering¹.

You might have noticed that Japanese POWs were in a very low number. They literally fought to death and then some more.

For example, in the Battle of Okinawa, the Japanese garrison of 77,000 mainland troops was virtually wiped out.

In the Battle of Saipan, only 921 surrendered out of a 31,000 strong garrison. The rest chose death.

In the Battle of Iwo Jima, out of 20,000 defending Japanese troops, 17,845-18,375 were dead or missing. Only 216 surrendered, which is both horrifying and astonishing when you see the size of opposing allied force.

In most hopeless situations where any other Army would surrender, the Japanese attacked. The results were as you can imagine, all-out slaughter.

Technical stagnation

Then we have the technical stagnation of the Japanese war machine. It is often said that a weapon is as good as the soldier wielding it but nevertheless having a good weapon is necessary. The superb soldiers of the Japanese forces were without a doubt badly equipped as compared to their adversaries.

The standard rifle of the Imperial Army was the Arisaka. After Manchuria, however, Type 38 was upgraded to Type 99 (though both rifles continued to stay in service, causing troubles in terms of ammunition supply). The integral magazine could hold five rounds. Because of the limitations of Japanese metallurgy, the barrel could not take a very high chamber pressure, but the Japanese compensated by making the barrel unusually long. However, the Arisaka proved satisfactory for jungle fighting, where its weak report and lack of flash and smoke aided concealment. On the other hand, its bullet made a distinctive cracking sound that was easily distinguished from Allied rifles during firefights, and some Japanese veterans envied the higher effective rate of fire of Allied rifles.

The Japanese were lagging far behind the West in terms of artillery, armored vehicles and cavalry. Most of their machine guns were also notoriously unreliable. Please refer to Schwern's answer to know more about small arms of IJA.

IJN vs IJA

The Imperial Navy was in better material shape than the Army when war broke out. Its sailors were well-trained and its main combat units were comparable in quality with those of Western navies. The Yamato, which was just being completed as war broke out, was the largest, most powerful battleship in the world. Japanese carriers lacked catapults and were somewhat lacking in underwater protection, but were otherwise the equal of their American counterparts. Japanese cruisers and destroyers were lacking in antiaircraft protection, but were armed with the deadly Long Lance torpedo, which was far superior to anything in the Allied arsenals.

Japanese Aviation

The Japanese Airforce & Naval Air arm shocked the West when they were first encountered. The Zero fighter was faster, more maneuverable, and had a longer range than most Western aircraft of 1941. It would be some time before its weaknesses were discovered. Japanese bombers were long-ranged, but vulnerable, and Japan never created a true strategic bomber. But Japanese light attack aircraft, such as the Kate and the Val, wrought havoc on Allied shipping. But almost all Japanese aircraft were dangerously lightly armored (And saw little progress as the war danced on), thus proving to be flying coffins by the end of the war. (Rather than despairing, Japanese made use of the flying coffins to be literally flying coffins, launching Kamikaze attacks on Allied shipping)

Role of poor Logistics

The Inadequacy of the Logistical Corps of the Imperial forces made the situation even worse as almost all of the military graduates chose other branches than logistics. At the time of the Russo-Japanese War of 1905, only 4 percent of military academy graduates were choosing to go into the logistics corps. Soldiers suffered due to this, whether due to lack of food, ammunition, equipment or medical care, thus escalating death rate. The tropical terrain of Pacific theatre was specially unforgiving. Diseases were common and in some instance due to lack of food, soldiers turned to cannibalism.

As mentioned by Tom Au, also in later stages of the war when the Japanese had lost the ability to counter-barrage, the Allies always began their attacks with heavy aerial and naval bombardment barrages which were used to kill as many defenders as possible and crack open as many defensive positions as possible. After Guadalcanal, the Japanese rarely bombarded Allied positions while an IJ soldier would have to endure hours and even days of shelling.

Sources

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_{1. Many Historians and Japanologists such as James J. Weingartner, Niall Ferguson and Ulrich Straus are of the opinion that Allied Forces deliberately acted to minimize the number of POWs and actively strived to not to take any prisoners as Japanese were viewed as subhumans and animals much like Nazis viewed Soviet Soldiers}

Answer 2

I want to supplement NSNoob's answer with some more information on Japanese small arms. They lacked the firepower which the Americans could bring down, firepower which is very important in obscured and close range jungle fighting.

Compared to the Chinese, their primary land opponent, the Japanese army fared fine. This is something very important to remember, the bulk of the Japanese army was fighting in China. The Chinese army was poorly supplied, poorly trained, and the Japanese arms and tactics did fine against them. Compared to the Americans, their primary opponent in the Pacific, Japanese equipment and tactics were obsolete.

For example, the standard Japanese rifle was the Type 38 and Type 99 "Arisaka". This was a very long bolt action rifle from the turn of the century. It was a good bolt action rifle, but it was still a bolt action rifle.

Source. That's a Japanese soldier with a Type 38, just to give you an idea of how long and unwieldy this rifle was.

On a similar vein, Japanese troops lacked a good submachine gun for mobile, short range firepower.

In contrast, US soldiers and marines could expect to be issued semi or fully automatic weapons as standard (with notable exceptions during the early war as the US was still gearing up). Primarily the excellent M1 Garand and the light and handy M1 carbine. For submachine guns the US had the heavy and expensive, but available, Thompson and later the light, cheap, and brutal M3 "Grease Gun". This allowed every US unit to pour out firepower, even rear echelon units would have carbines and submachine guns, very useful for close jungle engagements.

Japanese did have excellent machine guns. The Type 96 and Type 99 Nambu light machine guns (video on that from Forgotten Weapons) and the Type 92 heavy machine gun (and a video on that). While the US was making due with the WW1 vintage not-really-a-light-machine-gun BAR, and the heavy, but reliable Browning 30 cal for most everything else.

Source. That's a Type 99 light machine gun, and the bayonet is not a joke. It was a standard feature and says a lot about Japanese army mentality that they would put a bayonet on a crew served weapon.

The Japanese were entirely capable of producing better small arms, but nothing in the millions like they did the Arisaka, and little got to their island garrisons. They did have a submachine gun, the Type 100, but only produced about 25,000. They even copied the Garand (video about that copy) and Pedersen (video) semi-automatic rifles. By the time they realized they needed a better rifle, it was too late. Their production and transport system was a shambles.

This was due to a combination of limited production capacity, the pressures of keeping their army in China supplied, the supply problems caused by the Allied interdiction campaign, the lack of a private arms industry to supplement and innovate, and a general feeling that soldiers and spirit won battles.

Answer 3

In some ways, the Japanese casualty rate was not that much higher than that of the Americans. If you take casualties as "killed and wounded," the Japanese to American casualty rate was less than 2 to 1, and sometimes as low as 1 to 1. What is true is that the Japanese ratio of killed was much higher. The reason was that essentially all Japanese casualties were "killed" while most American casualties were wounded.

Okinawa is a case in point. Wikipedia lists American casualties (to the nearest thousand) as 20,000 dead, 55,000 wounded, 26,000 psychiatric, that is 75,000 physical casualties, 101,000 in all. Japanese casualties were estimated at 77,000-110,000 dead, 7,000 known be captured, approximating the American toll.

One disadvantage the Japanese had was that they were trapped on Pacific islands. American "wounded" were usually evacuated and nursed back to health; Japanese wounded were wounded repeatedly until dead, or they killed themselves. Few surrendered (the 7,000 at Okinawa was "high" in this regard).

Answer 4

My uncle was a Marine in these battles. His generation spoke very little about the war. He was in the Pacific. One day we were discussing wars. He turned to me and said:

"You know we did not take prisoners...".

There were many reasons for this:

1. There was no place to put or hold prisoners.
2. You had to be constantly on alert with Japanese prisoners since they were adept at unarmed combat and would prefer to die while killing an enemy
3. It was well known that the Japanese had beheaded soldiers who surrendered. They believed a soldier that surrendered had no honor

Given all those considerations, it was simpler and easier "not to take prisoners..."

Answer 5

I wanted to add a few thoughts and tie it all together.

Short Answer: After the first few months of the Pacific war the industrial differential between the two countries increasingly lead to a colossal mismatch in logistics, arms, supplies, and troops. The beginning and early conduct of the war, justified almost any barbarity in matching the enemies fanatical nationalism. In the latter period of the war the United States demonstrated it had more than a bit of fanatical nationalism of its own. No Quarter given on either side of that theatre of WWII.

Longer Answer: First off, Japan did have fine fanatical soldiers well trained and motivated; as has been previously stated. That had nothing to do with the lopsided casualty rates. If anything their fine military would have lessened the lopsided casualty rates Japan suffered after the first six months of WWII. The lopsided casualty rates came from two factors. (1) Japan picked a fight was an industrial super power which they never had a chance of winning once the war became one of attrition. (2) How Japan picked that war, and their conduct in the execution of that war when they had the upper hand was by most American accounts cruel, honor-less and pitiless and that's exactly the emotions they faced in return as millions of Americans volunteered to go to the Pacific and sort out this enemy.

(1) Japan wasn't an industrialized country. Japan at the onset of WWII could muster at best about 10% of the United States industrial output. They were a feudalistic agrarian society with an oversized miltary. The United States was already the leading industrial economy in the world, with a rather undersized military in 1941. A war of attrition, which is what WWII turned into, was not ever going to favor a Japanese victory. Japan's strategy was to hit hard and hope for a negotiated peace. When that failed so did any chance for a Japanese victory. Regardless of the quality of their soldiers they were outclassed by US production across the board. Take the battle of Iwo Jima for example..

source

183,000 U.S Army and Marine Corps troops, carried in 430 ships and craft, and over 747,000 measurement tons of cargo

That's more than 4 tons of logistical support for every sailor, soldier, and marine who participated in the Battle of Iwo Jima. Compare that with the logistical support the 20,000 Japanese defenders. Japan planned for logistics support for their soldiers measured in lbs per soldiers, not tons.

Another Example... How many Capital Ships did the United States produce between Dec 1941 and 1945? Literally thousands. How many did Japan produce. None.. They basically fought the war with what they had. They lost 4 aircraft carriers at midway, and never produced a single fleet carrier which production started after Dec 7th...

Source

At its peak, the U.S. Navy was operating 6,768 ships on V-J Day in August 1945, including 28 aircraft carriers, 23 battleships, 71 escort carriers, 72 cruisers, over 232 submarines, 377 destroyers, and thousands of amphibious, supply and auxiliary ships.

Source
Ship Class------------------US (Japan)
AirCraft Carriers-----------124 (18)
Battle Ships----------------8 (2)
Cruisers--------------------48 (9)
Destroyers------------------349 (63)

The logistical mismatch gave the United States the means to utterly destroy the Japanese wherever they found them.

(2) As for the motivation, it cannot be emphasized too heavily how angry both the sneak attack on Pearl Harbor made the United States, and the subsequent poor treatment prisoners of war endured at the hands of the Japanese. After Pearl Harbor the recruits who went to the Pacific believed they were in a fight with godless pitiless barbarians, and they were there to match that pitiless behavior. The Marines at Guadalcanal fought so fiercely that the Japanese believed the United States had paroled murderers and criminals to fight against them. The Marines loved that description so much it became part of the Corps Lore.

Here is a good article which details the wide spread mutilation of Japanese soldiers, living and dead which occurred during WWII.

Here is an image from Life Magazine published in 1944.

Photo published in the May 22, 1944 issue of LIFE magazine, with the following caption: “When he said goodby two years ago to Natalie Nickerson, 20, a war worker of Phoenix, Arizona, a big, handsome Navy lieutenant promised her a Jap. Last week, Natalie received a human skull, autographed by her lieutenant and 13 friends and inscribed: ‘This is a good Jap-a dead one picked up on the New Guinea beach.’ Natalie, surprised at the gift, named it Tojo. The armed forces disapprove strongly of this sort of thing.”

Clockwise from top left: U.S. soldier with the Japanese skull adopted as the “mascot” of Navy Motor Torpedo Boat 341 circa April 1944, U.S. soldiers boiling a Japanese skull for preservation purposes circa 1944, a Japanese soldier’s severed head hangs from a tree in Burma circa 1945, a skull adorns a sign at Peleliu in October 1944.

Here is a newspaper article from Nevada Daily Mail (see second column under "Sign of Nervousness") which talks about Roosevelt receiving a letter opener made out of the forearm bone of a Japanese soldier and he responds that "that's the kind of gift I like receiving".

So wide spread was the mutilation of Japanese soldiers that twice the Army Chief of staff had to order directives against the practice.

Throughout the United States’ campaign in the Pacific, American soldiers indeed mutilated Japanese corpses and took trophies — not just skulls, but also teeth, ears, noses, even arms — so often that the Commander-in-Chief of the Pacific Fleet himself had to issue an official directive against it in September 1942. And when that didn’t take, the Joint Chiefs of Staff were forced to issue the same order again in January 1944.

Why were the Japanese military fatality rates so high during WWII against the United States. Because from the American perspective of the period, those are the kinds of seeds the Japanese sowed and that's the resulting harvest the Japanese reaped.

Answer 6

I'm not an expert on this field, but just wanted to put out this thought, based on several historical studies.

The thought is, didn't the disparity really start to show up after the strategic naval losses? By that point, the defensive fights that the Japanese were fighting were almost exclusively scenarios where they were beseiged (aka, stuck on a island with no viable means to evacuate), critically low on food and water, and so low on ammunition that their combat response was affected.

The IJA forces stuck on the islands were basically left to die a slow death and given the coup-de-grace by an overwhelming amphibious landing force supported by naval forces as well as by air. I got the sense that many of the battles might have seen other national forces just surrender, except for Japan. IJA soldiers exhibited a fanaticism that trumped low morale time after time. I mean, look at the Italian forces who also had good soldiers but suffered from poor food, low ammunition, and essentially saw their forces suffer a catastrophic morale and organizational collapse due to these failures. It's pretty amazing that the Japanese soldiers refused to surrender and insisted on fighting even in those situations where they pretty much faced suicidal odds. And I think it's this fanaticism that led to the ratio that you're talking about. Without the fanaticism, the ratio would have been much, much lower, and the prisoner-of-war intake would have been significantly greater for the US forces.

I'm just thinking of the battles of Saipan, Okinawa, and Iwo Jima - but there were many other cases where the Japanese defenders, when faced with imminent, hopeless odds, stubbornly insisted on a bitter contest of arms, despite being unsupplied and low on ammunition.

Anyways, just my humble $0.02 worth.

Answer 7

As NSNoob has stated, the Japanese did do very individually, and in small groups when barely adequately supplied. Their land forces normally did so well that their reputation alone took Okinawa and the Philippines at the start of the war. In fact, the fighting soldier is the last link in a long supply chain (logistics), involving the entire industrial manufacturing chain. The Japanese problem began at the top of the chain, not at the bottom. They ran out of ships, pilots, and supplies. The Japanese took all those islands and China in order to secure resources for the war effort to hold said resources. They began the war with the strongest (numbers and effectiveness) Navy in the world at the time, and built only a few ships while the war was in progress. The US began the war with perhaps the weakest in numbers, effectiveness and training (take the fact that Pearl Harbor was a success at all as an example) and ended the war with a 1000 ship navy. The Japanese saw the writing on the wall long before the Allies did and built 25 aircraft carriers, but they didn't replace them as they sank (no resources or manpower) and couldn't/didn't train pilots to fly them. So the individual soldier was essentially by 1943 swinging gently, gently in the wind. The stagnation of the Japanese war machine was the result of the impairment of the entire resource manufacturing chain as NSNoob alludes. There was no absolute guarantee that the Japanese were going to come down on the Axis side until the UK saw their increasing naval strength and moved to block their access to resources. This put them firmly in the Axis camp. The UK had a several hundred year policy of maintaining the strongest single navy in the world, and moved to block any other country that attempted to contest this. Supply chain movement by weight tells the story, the US could put 10lbs per solider per day on the ground and the Japanese averaged around .1, the Germans 2lbs (before Casino). The IJF tactical manual estimate 4.2 pounds per day.