The most amazing thing about the Japanese during the Second World War was not the legendary drive, dedication, obstinacy and unwillingness to give up, of the general soldier, sailor or airman; it was the dismal failure of their leaders to use that resource to good effect.
Many people will point to the stunning Japanese run of victories in the first few months of the war to scoff at this statement, but they are wrong. It is not surprising that skilled and dedicated troops can surprise and overwhelm unskilled and unprepared ones (particularly those who lacked much vital equipment). It is however, very surprising that those troops could not be put in a better long-term position by their leaders.
In fairness, it must be stated that Japan could never win in the long term: as long as the Allies held it together enough to rebuild and return to the conflict. Even the conquest of India, Australia, and Hawaii, and the complete laying waste of all Californian factories, and the Panama Canal by the Japanese, would only have held of the inevitable for a while… If the Japanese ever had the ability to try these. They did not. With most of their troops tied down in China: only a dozen mobile divisions available to fight the whole perimeter; and never enough shipping to supply them all even before impossible plans like invasions of vast new countries were even considered; that is all a pipe dream. (I suppose carrier raids on the US coast or Panama were not impossible, but the Japanese had an appalling record of damaging anything not considered a proper military target. It is what the American’s call an ‘aggression’ thing – too macho to shoot at unprotected targets. See the complete failure of Japanese submarines.)
In practical terms the only thing the Japanese had going for them was surprise; an initial ability to concentrate forces and equipment before their opposition could react; and the skill and dedication of the troops fighting beyond the supposed limitations of their equipment and supply lines. Once those assets were gone, so was any chance of victory. After that the bad leaders tried to hold on to whatever chances the self-sacrifice of their troops could deliver. In the end that came down to ‘can we sacrifice enough lives to make the Allies believe that they will loose too many men to get unconditional surrender’. A strategy of desperation.
Japanese generals did fairly well at he start. By moving faster than expected; by outflanking all opposition through greater manoeuvrability; and by taking whatever casualties were necessary to maintain momentum; they swept aside an ill prepared opposition as easily as the Germans did in Poland, Norway, France, the Balkans or Russia; or as the British did in North and East Africa, and later in France; or as Americans did in French North Africa or France; or as the Russians later did in Russia and Poland and the Balkans; etc. Actually, come to think of it, they had exactly the same effectiveness of any concentrated and prepared force against a dispersed and weak or unprepared one, as has any similar situation in history. Only when conflict got down to something closer to even odds in New Guinea or Burma did the Japanese generals start to look incapable of puling any rabbit out of their hat, other than the gritty endurance of the common soldier.
The Japanese Admirals were far worse. They failed consistently and spectacularly, right from the start. They won victory after victory from their initial position of concentration and surprise, but they never followed up! They failed to convert any tactical victory into a strategic one… with the possible exception of the Battle of the Java Sea.
At Pearl Harbour they slaughtered major ships, and then wandered off leaving the oil tanks, supply depots, repair shops, and harbour facilities almost untouched.
Off Malaya they sunk the two nearest British battleships (their was another battleship and an aircraft carrier in the Indian Ocean and more on the way, but they are rarely mentioned), and achieved theoretical superiority at sea and in the air. But the British ran dozens of convoys into Singapore and Jave without a single loss until the final evacuation!
Off Java they defeated and dispersed the Allied cruiser force, and successfully invaded Java. This would be the best example of a tactical victory followed by a strategic gain at sea.
At Darwin they slaughtered allied shipping, but wandered off and left the port operational!
At Ceylon they sunk some ships, but left the British fleet in being, and the RAF in control of the air after their carriers withdrew. The total effects of the raid were about the same as a successful cruise by a couple of the better German U-boats.
At Savo Straights The Japanese slaughtered the guarding cruisers, and then wandered off without attacking the vulnerable and vital invasion transports.
At the Phillipines they actually achieved what they had sought all along, with a strong battleship force breaking through after horrendous casualties to face a practically unprotected invasion fleet. But once again they then wandered aimlessly for a while before leaving without sinking anything of note.
The repeated element here is an admiral achieving the initial tactical objective, and then apparently not having a clue how to convert that to anything resembling a strategic success!
Let us start with Nagumo, who has gone down in history as one of the most successful admirals ever, but who turned everything he touched to pathetic disaster.
At Pearl Harbour your average gibbon could have succeeded in suprising the Americans and clearing the skies for strikes on the fleet. However it is likely that the average gibbon would have followed up with the third strike his staff was begging for, rather than turning for home. With six carriers available, he could have easily held a strike bigger than any launched at Midway in reserve, while continuing to pound the base. It was morale weakness and strategic stupidity that led him to withdraw instead of follow up. Yamamato was horrified at the result.
At Ceylon we see the same. His strikes were successful, but his follow ups were indecisive. Two cruisers heading south were sunk, and a scouting carrier borne plane from the fast approaching British fleet intercepted; so he turned away and failed to search in that direction the next day.
At Midway he changed his mind at the wrong time, and suffered the consequences. Then his follow-ups were incompetent guesses. Nonetheless it is undoubtedly fair to say that he fought harder and more sensibly at Midway than in any other engagement of his career. Failure was more due to bad luck there than success was to good luck anywhere else he fought.
The overall assessment of Nagumo is pretty unimpressive. He was a battleship general put in charge of the carrier strike force for no other reason than the fact that he was next in seniority. He did not appear to understand his weapon well, and he certainly did not use it to its potential. The fact that his initial strikes against unprepared and often weak targets were usually successful accords him no greater place in history than the American admiral who commanded the successful fleet at what is now called ‘the great Marianna’s turkey shoot’ (go on name him): in fact, probably less. He partly succeeded on a couple of walkovers, and partly or completely failed on a couple of fleet engagements. He never turned tactical victory into strategic success, and managed to turn even successful operations into strategic failure before sacrificing his nations last chance of victory (to an admittedly clever trap.)
So what about Yamamato. He is generally regarded as the strategic genius who, in his own words, would run riot for a year. In fact he ran riot for about three months, jostled somewhat ineffectively for position for another three months, and was then decisively defeated in the major fleet engagement he had been seeking.
The period of success was an almost inevitable effect of surprise and concentration. Nothing his opponents could have done at the time would have changed that. (Though given another few months, the British Eastern Fleet would have been too big to allow him to send his entire strike force to Hawaii at the start of the campaign.) Nonetheless he failed to exploit any local superiority beyond purely local effects. No strategic victory, only tactical. Verdict… He moved his pieces well when there was little opposition, but only short term.
The period of jockeying for position was less impressive. The fleet he sent to Ceylon should probably have been capable of taking on the BEF successfully, if they manoeuvred well to stay clear at night and strike at day. Possibly he cannot be found wanting in that they failed. Nagumo was not his choice, and Somerville was too experienced to do anything stupid. But why no follow through? The BEF should have been pushed harder to try and get results while the Americans were still playing dead. Yamamato could not have known how many reinforcements the BEF had due within two months (The battleships Nelson and Rodney to add to the five already there, and the aircraft carrier Illustrious and possibly another to add to the three present, and more cruisers and destroyers, etc), but he must have known the margin of superiority could only decline. Yet another strategic error. Verdict… lack of decisiveness.
At Midway he committed an unforgivable sin. Dispersion of resources over vast areas. Even after the four carriers of the strike force had been sunk, he had more carriers with more planes available for the operation than the Americans had had at the start. Unfortunately they were spread to hell and gone all over the place. Some with the main body, far too behind to support the strike force; and some way up in the Aleutians running a pointless diversion. (Recent research seems to indicate that the Aleutians diversion was a brainwave of the Naval Staff, which Yamamoto had to accept as he haggled for thee rest of his plan - a comment on institutional incompetence in its own right). Had two or three of those carriers been supporting the strike force, or had the main body been close enough to follow up the battle immediately, there is little doubt the Japanese could have won. Verdict… Idiot.
Possibly it is a good thing for his memory that he died before the final disasters. One can hope that if he had been the one to break through at the Phillipine Sea, he might have at least pushed the damage bill before retreating. But the dispersal and lack of follow through was so familiar from the operations he had planned, that it is likely the faults were institutional rather than merely personal. Certainly his successors had very similar preferences for over-complicated plans with pointless dispersal of effort.
In fact the Imperial Japanese Navy approached the Second World War with all the impulsive aggression and enthusiasm, and all the lack of coherent strategic planning, of such well known military experts as Lord Cadogan and General Custer. It was not that they lacked the ability to win, it was more that their institutional mindsets were incapable of envisioning a coherent method to achieve victory.