Oh boy oh boy oh boy~

So in a nutshell, Japan's military as a whole was an utter organizational disaster. The usual interservice rivalries-for instance, the constant ribbing between US Army and Navy-had escalated out of control to the point of near hostility, the military itself had effective control of the civilian government without any civilian oversight on its own activities, and the military itself also had several internal factions that disputed strategy (the Hokushin-ron and Nanshin-ron, or Go-North and Go-South factions, respectively).

So this was bad enough. But the Imperial Japanese Navy was on itself another total disaster zone.

The first thing about the Japanese military as a whole was that it was extremely hierarchical, and physical violence was seen as an effective method of discipline. Tameichi Hara recalls walking into his dorm as a cadet for the first time and getting punched in the face by one of his seniors for failing to salute him. While there were certainly many members of the Navy who tried to change this-in fact, Hara noted that Admiral Yonai ordered a halt to physical discipline shortly after-but it was difficult to change something so thoroughly ingrained in the institution, as Hara found on several of the vessels he captained.

This created an extremely toxic culture where men and officers would often be inhibited from criticizing the decisions of a superior. This isn't to say it didn't happen-for instance, nearly every captain who went on the final suicidal sortie with the Yamato in Operation Ten-Go said it was a stupid idea and a waste of lives and ships-but in cases where the leader was especially charismatic or powerful-like with Admiral Yamamoto-dissent was highly discouraged. Parshall and Tully, in Shattered Sword, wrote about the planning and wargaming for the Midway Operation, where first, when the "enemy" team conducted a maneuver that ended up being very similar to what the US Navy actually did, Yamamoto's chief of staff Ugaki ruled that it was "unrealistic" and undid that team's actions. Then when the carriers took simulated damage, he also considered the damage "extreme" and reversed it. One can easily imagine such criticisms as being points that could have been corrected in the Japanese battle plan that ended up being crushed underfoot by this sort of conformist mindset.

Another overfocus by the Japanese was their attitude towards attack. For instance, damage control was relegated to a small group of specialists aboard each vessel. The idea was that everybody had their own role, and that everybody should get very, very good at what they did. However, this contrasted to the Allied training regimes, which mandated that all crew needed to be able to perform damage control routines. In the end, this made a difference at both Coral Sea and Midway, where the US Carrier Yorktown was able to be saved by her damage control parties, and where the Japanese Carrier Akagi had her fires burn out of control when she may have had a fairly good chance of survival.

This also applied to Japan's armament of her ships. The Americans used torpedoes propelled with carbon dioxide, which was more obvious (the air bubbles being visible) and also resulted in less range in the torpedo. The Japanese used oxygen torpedoes, which were harder to spot (due to emitting smaller air bubbles) and had much longer range: however, this was offset by the massive risk of having highly volatile and flammable oxygen being stored in a relatively unprotected spot on a ship. In the case of the IJN cruiser Suzuya, a near miss caused her torpedoes to blow up and ended up sinking the ship.

This also applied to the general construction of Japanese ships. There was an idea that the Japanese ships needed to be able to outfight the Allied ships. As a result, this meant that many of the Japanese ships were designed to contain more firepower than other ships of their size. However, this resulted in several disadvantages-for instance, the Takao-class cruisers were notoriously top-heavy (making them less stable), and the Mogami-class was designed in such a crappy way that shooting a broadside would loosen rivets and weldings in the ship.

And I'm not done-this was also a factor in the construction of their planes. Japanese naval aircraft were relatively unarmored to their Allied counterparts. This was because they wanted to maximize the speed and range of their aircraft, which was an advantage when they initially engaged Allied aircraft as they were able to outfly and outmaneuver their opponents. However, more advanced Allied aircraft-like the Hellcat, the Lightnings, and the Thunderbolts (also known as "Juggs" for their durability) were able to maneuver with the Zeroes as well as be much much harder to bring down. This resulted in rather lopsided kill ratios as the war went on.

Anddddd this also applied to the pilots as well! The Japanese pilot training regime intentionally failed most of the candidates so as to cultivate an elite force. However, this had the notable disadvantage of making it extremely expensive to replace elite pilots, which meant that by the end of the war Japanese trainees were getting cut up by constantly improving Allied veterans.

The last thing to talk about is the doctrinal differences. The Japanese operated under the assumption that the Allies were going to mass a counterattacking fleet at some point to retake the territories the Japanese took. As a result, the Japanese intended to capture a large defensive perimeter, using island airbases to supplant the aircraft carriers in defeating the Allied counterattack. The idea was to use the aircraft to contest air superiority, followed by a massive night engagement where cruisers and torpedoes would fire torpedoes, and the Japanese fleet with their superior night-fighting skill would annihilate the counterattack, causing such losses that it would drive the Allies to negotiate. This is what is called the "Mahanian Decisive Battle," named after Alfred Mahan, who was a naval theorist that believed naval warfare would culminate in a mega battle between the massed fleets of both parties, ala Jutland.

The problem with this strategy was that it depended on the Allies to do exactly what the Japanese wanted them to do, which is a poor operating premise. As it was, the Americans did indeed have a war plan to do just that, called War Plan Orange. However, War Plan Orange was already being redesigned to call for a more-carrier focused doctrine that was later implemented during the war. Speaking of which, both Japan and the US, prior to the war, believed in the primacy of battleships over aircraft carriers. However, the US had shifted in its priority of weapon systems, such that in the 1940 budget they commissioned 10 Essex-class carriers as opposed to 4-6 battleships (the exact number eludes me at the moment). Thus even with the Pearl Harbor strike disabling the US battleship line, it did not significantly affect American war plans. On the other hand, the Japanese were battleship focused to the end, and thus they developed the Yamato-class battleships, which ultimately were... underwhelming in their combat performance, although that had more to do with Allied air superiority than anything else.

I've got to run, but I can go on about how Japanese operational security was absolutely TERRIBLE compared to Allied ones (and I"m not even talking about the codebreaking!), how Japanese logistics were pisspoor, the terrible state of Japanese anti-submarine warfare, and so on...

Sources:

Evans, Kaigun

Parshall and Tully, Shattered Sword, et. al

Hara, Japanese Destroyer Captain

Asada, From Mahan to Pearl Harbor