The general argument goes something like this:
- Japan was running out of trained pilots
- Japan couldn't spare the fuel to properly train more pilots
- But they had plenty of planes.
- Thus untrained kamikaze pilots are more effective than untrained conventional pilots, and they used less fuel.
It can be argued that it was the most effective tactic for the situation they found themselves in, and I'll leave that argument to Military History Visualized: Kamikaze Tactics - Insane or Rational?. Because it was a more effective tactic didn't make it an effective tactic, as we'll see below. And it doesn't make it an effective strategy, meaning a plan to achieve their goals.
What was Japan's goal? The general argument goes something like this:
- Japan couldn't/wouldn't surrender because the US demanded Unconditional Surrender and the Japanese wouldn't risk it.
- Therefore Japan had no choice but to...
- Defend the home islands to the last and/or
- Make the invasion so costly the US will negotiate.
I'm not aware of the US demanding unconditional surrender until the Potsdam Declaration in July 1945, Japan knew the war was lost a year before that. And how are they supposed to use kamikaze to force negotiations if the US won't negotiate?
However, Japan was trying to negotiate an end to the war... in a piecemeal and lackluster fashion. They were also preparing a desperate defense against invasion... while throwing away battleship Yamato to save face and continuing to fight on the mainland (note: I don't have much information about what their thinking was for their mainland army).
If that doesn't strike you has a coherent strategy, it wasn't. Japanese high command could not come to a consensus about how to end the war right up to the end. Were kamikaze pilots [part of] an effective strategy for Japan? Which strategy? Japan was fighting to the last, fighting to negotiate, fighting in China, and willing to accept unconditional surrender all at the same time.
Whichever way you slice it, the kamikaze strategy was supposed to make invasion so costly the US would blink first. From day one Japan made many bad bets on US resolve and always lost. In the end Japan blinked first under the weight of an entirely predictable worsening situation.
Kamikaze strategy only works if you have the resolve to see it through.
While they were probably doing more damage than they could with conventional attacks, they weren't doing significant damage to an increasingly overwhelming Allied fleet. With conventional attacks the Japanese sank roughly 2 battleships, 4 fleet carriers, 1 light carrier, 3 escort carriers, and 7 heavy cruisers without even getting into the lighter ships. In comparison, kamikazes sank 3 escort carriers, 14 destroyers, and a few dozen transports and auxiliaries. Additional heavy vessels were damaged, but the US was very good at repairing ships and their experienced crews would fight on.
The impact of kamikazes gets worse once you look at them in context. After Hornet was lost at Santa Cruz in Oct 1942, the damaged USS Enterprise was the only operational US fleet carrier. The naval battles of Guadalcanal were chewing up US cruisers and battleships such that they were running out. Each US vessel damaged or lost during this period could have a large impact on the war.
Fast forward to the Battle of Okinawa, April 1945, and the Allies arrive with...
- 17 fleet carriers
- 6 light carriers
- 22 escort carriers
- 20 battleships
- 14 heavy cruisers
- 20 light cruisers
Much is made of USS Bunker Hill, but damaging even several fleet carriers is not going to stop this fleet. Their crew will survive. Their air groups will survive and can be reassigned. The ships will be repaired and return for the 1946 invasion. A dozen more were being built or working up.
Tactically it was ineffective. Strategically it was hopeless. The Japanese were throwing away aircraft, fuel, and pilots they could have been husbanding for the invasion of the home islands and not even gaining a local tactical advantage for it. It only made the situation worse.
"Resorting to an extraordinary measure"
Conventional vs kamikaze presents a false dichotomy between very hopeless and hopeless. There was one sane option on the table:
surrender effect a settlement of the present situation by resorting to an extraordinary measure as the Emperor put it.
Japan made a number of bad bets about attacking the United States. All of Prime Minister Tojo's offensives in 1944 failed and he was forced to resign. Prior to the Potsdam Declaration of July 1945 Japan could have negotiated while they had something to negotiate with. Starting in spring 1945 the Japanese began pressing the "neutral" Soviets to mediate peace talks with the US. The Soviets strung the Japanese along while they planned to invade Manchuria. At best the Japanese could hope the Soviets waited until their neutrality treaty expired in April 1946. They didn't.
After Potsdam the Japanese could have simply accepted the terms, or just tried to negotiate anyway. They did both. Right up until the Emperor made his decision the Supreme War Council was split between accepting unconditional surrender and trying to hold out for some guarantees and concessions.
Kamikaze tactics were not going to win the war; they were never going to get better at it, and the Allies were only going to get better at defending against it. While Japan had large reserves of aircraft, they did not have the industry to replace them. Their kamikaze attacks would only get weaker using fewer and increasingly obsolescent aircraft and pilots with less and less training. The Allied fleet was only going to get stronger with more and increasingly superior aircraft and training.
Even if kamikaze convinced the Allies that invasion was too costly, the Japanese knew the Allies were not going to fight their way across the Pacific and then just walk away. The best outcome they could hope for was blockade, bombardment, bombings, starvation, revolt, and Soviet invasion.
The issue of Japanese surrender is a very large topic: the fear of unconditional surrender, the sanctity of the Emperor, military leadership sacrificing their people to stay in power... I have my own answer. I just want to remind everyone that when discussing last-ditch WW2 tactics, even if they didn't like the terms, surrender was always an option. And that's the option Japan took after a year of bloodletting.
Why no trained pilots?
Kamikaze tactics were the result of multiple failed strategies. Why did Japan have a shortage of trained pilots? Why did they have a shortage of fuel? These problems could have been solved, or mitigated, well before the situation became desperate. Even before the war started.
Japanese aviation was set up for a short, sharp war. They had their existing squadrons of highly trained pilots, but limited means of replacing and replenishing them. Unlike the US, they did not set up a continuous training regimen to make good their losses. While in the early war they might have outfought the Americans, every lost pilot was irreplaceable. Japanese aviation got weaker and less experienced while the US got stronger and more experienced.
The Japanese started the war with a superior but "unbalanced" aircraft, the A6M Zero. It required an experienced pilot to exploit its strengths and protect its weak points. Increasingly experienced US pilots learned to overcome their aircraft's disadvantages and exploit the Zero's weaknesses with tactics such as the Thach Weave. Superior Allied aircraft arrived, such as the F6F Hellcat and F4U Corsair. The Japanese continued to fly the Zero with less and less experienced pilots culminating in the Battle of the Philippine Sea aka the Great Marianas Turkey Shoot losing 600 aircraft and their irreplaceable pilots.
It didn't have to go this way. The Japanese had been at war for years prior to attacking the US. They had ample time to establish a proper pilot training and air group rotation system to make up for wartime loses.
Increasing loses of existing airframes due to loss of experienced pilots diverted resources away from developing superior aircraft such as the N1K and Ki-84 delaying their introduction until it was too late; there wasn't the fuel to use them, nor the experienced pilots to exploit them.
Why no fuel?
Why did the Japanese have a shortage of fuel? They succeeded in March 1942 conquering the oil fields of the Dutch East Indies (Indonesia). They had plenty of capacity in Japan to refine fuel. But they were losing it in transit to an increasingly effective American anti-shipping effort. Despite being an island nation and able to watch and learn from British experience in WW1 and WW2, their anti-submarine equipment and tactics were very poor. They never employed a convoy system. The situation became so desperate they resorted to using small cargo ships and tankers hugging coastlines in the hopes of avoiding Allied submarines and aircraft.
This entirely predictable situation could have been mitigated before WW2 even began. Prior to the war, the US oil embargo was a major threat. Capturing the Dutch East Indies was a vital strategic necessity. Even as the Japanese were planning to launch the Pacific War to get oil, they were watching Germany attempting to strangle Britain with submarines and commerce raiders as they had done before during WW1. To kick off a war to get oil without a plan to protect it while it gets to where its needed was negligent.
In conclusion, kamikaze tactics only make sense when compared to conventional tactics in an already hopeless situation with surrender taken off the table. But surrender was always an option, negotiated or unconditional. That Japan found itself lacking experienced pilots and fuel was in part of its own strategic negligence. Kamikaze drew irreplaceable resources away from the final defense of Japan to inflict replaceable and inconsequential losses on a growing Allied fleet. The Allies repeatedly demonstrated they would not shrink away from taking casualties to end the war. Even if they decided not to invade, what then? The Japanese people suffer bombardment, starvation, and eventually revolt. In the end, it was the Japanese high command who did not see their own strategy through.
Kamikaze could not win the war, nor even win a battle. It could only get more people killed.