Was Radio Silence a key factor at Midway?

[oldpop2000]

The Battle of Midway is one of the most written about, discussed and investigated battles of WWII, at least by the US. We've discussed many aspects of this battle on this forum; the planning, preparation, execution et al. We've assigned blame for the disaster which caused the loss of four fleet carriers and one heavy cruiser.

We know that it was a gamble, but Yamamoto was a gambler. He knew that if Japan could not destroy our Pacific fleet in six months, that he could not guarantee the outcome of the war. This was the reason for Operation MI, as it was designated. In warfare, if you want the opponent to come to battle, you must attack something he has to defend. Midway was the thing we had to defend. It was the key to the Hawaiian Islands and possibly the West Coast. If Yamamoto could attack and occupy Midway, our carriers would have to give battle and he could destroy them. The occupation of Midway would give the Japanese a platform for bombers and fighters to attack and possibly force the US Navy to abandon Pearl Harbor as a main fleet base and move back to the coast; 2200 miles further to the east. 

Yamamoto met much resistance from the Naval General Staff until the Doolittle Raid, after which he received full support but one further operation was added; the attack on Dutch Harbor in the Aleutian's and the occupation of Kiska and Attu Islands. The NGS felt that this operation could eliminate any possibility of the US using this region as a staging area for an attack on Japan. It would also serve as bait for carriers. If they attacked the Aleutians first, our carriers would leave Pearl Harbor and race north. This would make them vulnerable to interception by submarines and Nagumo's carriers coming in the 320 degrees.

Nagumo's carriers were to arrive about 175 miles from Midway on the 4th of June( our time, Japan would use Tokyo time, 5 June), launch an early morning attack to soften up the islands defenses, then await news of our carriers. Yamamoto would be 300 miles behind him with the rest of the fleet which included eight battleships. His job was to finish off the US fleet including any battleships that were found.

The invasion force moving west from Saipan would then arrive, launch the land attack and occupy the island, after Nagumo had softened up the defenses. This was the essence of the plan. It was complex and required 256 ships to coordinate over about 7000 miles. A daunting task, if you will.

With the benefit of hindsight, we know that the operation was far too complex to be coordinated accurately. We know that the Japanese had assumed that Yorktown had been sunk at Coral Sea and that their four carriers would be sufficient to handle our two carriers. The whole success of the plan was predicated on surprise, an important aspect of any operation. Surprise as to initial objectives, intermediate objectives and final objectives; force structure and deployment; timing and direction of attack. All of these aspects are vital to the success of any operation; be it naval, air or land.

I will address surprise and security in the next installment.

Thanks

[oldpop2000]

Secrecy is vital for any operation. Your objectives, force structure, movements to contact must be kept secret. Secrecy entails coding vital messages and information transfer between forces and headquarters. If the enemy can read your mail, your operation is immediately compromised and in jeopardy.

The other procedure if you wish to call it that, is radio silence. Once the operation has commenced, forces should be silent except between units. This will prevent the enemy from detecting transmissions and identifying the direction of travel and possible objectives. However, radio silence can be a hindrance to the flow of vital intelligence to the forward elements. These forward elements are acting according to a plan and that plan was based on an intelligence assessment. This may have been the problem at Midway. Here are my thoughts.

Admiral Nagumo stated in his Task Force Operational orders that " the enemy has no knowledge of this plan". This governed how he would conduct the battle. He would launch an air strike on Midway, and wait for the invasion force, support it but be prepared to attack the US carriers when they were within range. This was the plan.

One of the most important aspects of any plan, is to continually update the intelligence assessments after the operation has begun. Your advanced forces are planning their portion of the operation based on the initial assessments of the enemy strength and deployments and if that changes, it might be necessary to inform those advanced forces to be able to adapt to the new information. For Midway, Operation K was the part of the plan that would confirm the location of our carriers at Pearl Harbor, which was what the original assessment had made. In other words, this is what Nagumo was acting under, the idea that our carriers were no where near Midway and he was free to conduct his land attacks until our ships were discovered by a line of submarines from Midway to Pearl Harbor. He would then ambush those carriers on their trip north, after the initial landings in the Aleutian Island. Any change in that assessment, might be vital to him in order to reorganize his attack plan.

So, what happened. Well, submarines were assigned to go to French Frigate Shoals, and refuel the flying boats from Kwajalein Island then overfly Pearl Harbor and radio whether the carriers were in fact in the harbor. Unfortunately, they found two US Seaplane tenders in the harbor with PBY's. Eventually, the operation was suspended. This action was never conveyed to Nagumo because of radio silence. It was felt that radio silence was more important than the possible knowledge that there was no confirmation that the carriers were in the harbor. So, the First Striking Fleet continued on to Midway, if they heard no results from Operation K, they would assume nothing was worth reporting.

The next vital part of the plan that was designed to provide update intel on the location of our carriers was the line of submarines deployed to provide a cordon from Midway south to Oahu. Those submarines, at least part of them, were the ones designated to provide the fuel for Operation k. They were late to their assigned areas plus the other seven were also late. They would not arrive until June 3, one day before the attack. Admiral Yamamoto was apprised of this development, but Captain Kuroshima, the designer of the plan, was strongly opposed. He and others felt that Akagi, the flag ship of the first Striking Fleet must have surely picked up that signal. They had not, Nagumo again was in the dark and assumed that the operation had gone forward as planned.

Finally, Tokyo's radio intelligence had now suspected a US carrier force somewhere off Midway. Again, Yamamoto was inclined to relay that word, a very vital piece of information, to Nagumo, but was deferred by Kuroshima.

All in all, there was information that might have affected how Nagumo conducted the June 4th attacks and might have made a difference. He might not have made the mistakes he made, had that information been available but it wasn't. In Shattered Sword, Parshall makes the statement: "Indeed, the overall problem with Japanese communications had less to do with their inability to receive information than it did with Japanese emphasis on radio silence.....without a willingness to evaluate and act on information, all the radio equipment in the world wasn't going to help Nagumo. " There is more to this idea of radio silence. The prudent thing for Nagumo to do would have been to plan for the worst case; that the US carriers had sailed and were nearby Midway but he had no information to lead him to that conclusion, so he simply followed the plan. Maybe that was the big failure, not looking outside the box.

Almost all historians agree that the information should have been forwarded to Nagumo. They should not have relied on whether one of the ships in the fleet, possibly the battleships would detect the radio messages and pass them to Nagumo in Akagi. It is possible  Akagi with its low island and antenna heights was not the best choice for a flagship, one of the battleships with its higher antenna's might have been better.

This failure to pass vital information forward, might have been a key factor and the mistakes made on the day of the attack might have been avoided.

[steel selachian]

How strong were the Japanese signals intelligence indications that the US had a carrier force near Midway? Radio silence or not, that should have tripped someone's alarm bells. They had just gotten surprised by Lexington and Yorktown at Coral Sea and now they had indications that American carriers were again right where the Japanese were planning to go. To quote from a game, "One's an anomaly, two's a trend."

What I do wonder is how much overconfidence played into it. From some discussions we've had, it sounds like the Japanese assumed they sank two or possibly even three (depending on if they continued with the errant identification of Neosho as an aircraft carrier) carriers in return for the loss of Shoho and Shokaku getting pounded. If so, I wouldn't be surprised if Kuroshima was under the belief that Nagumo would do just fine even if he he got blindsided. A couple months later on Guadalcanal the Japanese army had the same issue when Colonel Ichiki thought he could just march his 900-man detachment right into what he thought were 2000 Marines (in actuality, over 11,000) and wipe the floor with them in a day.

[oldpop2000]

Jun 6, 2016 20:09:25 GMT -6 steel selachian said:

How strong were the Japanese signals intelligence indications that the US had a carrier force near Midway? Radio silence or not, that should have tripped someone's alarm bells. They had just gotten surprised by Lexington and Yorktown at Coral Sea and now they had indications that American carriers were again right where the Japanese were planning to go. To quote from a game, "One's an anomaly, two's a trend."

What I do wonder is how much overconfidence played into it. From some discussions we've had, it sounds like the Japanese assumed they sank two or possibly even three (depending on if they continued with the errant identification of Neosho as an aircraft carrier) carriers in return for the loss of Shoho and Shokaku getting pounded. If so, I wouldn't be surprised if Kuroshima was under the belief that Nagumo would do just fine even if he he got blindsided. A couple months later on Guadalcanal the Japanese army had the same issue when Colonel Ichiki thought he could just march his 900-man detachment right into what he thought were 2000 Marines (in actuality, over 11,000) and wipe the floor with them in a day.

You ask a good question, about how strong the signals intelligence indications were about a US carrier force near Midway. According Jon Parshall, each ship's wireless receivers were to be continuously manned and tuned to the broadcast of the First Communications Unit in Tokyo. This unit was responsible for relaying all messages received from the nits of the Combined Fleet back out to the forces at sea. All large ships carried a radio direction finding unit. The Akagi's post battle report noted increased patrolling by American aircraft operating out of Midway around May 29th.


NGS radio intelligence of May 31st, noted a number of enemy vessels participating in the Pacific Air Base Communications System and the General Ships Communications system in Honolulu had increased.

Radio traffic analysis show 72 of 180 intercepts were urgent with the heavy increase in US message traffic in the Hawaiian and Aleutian areas. This was unusually high. Apparently the Japanese were doing the same thing we were doing, except we had broken their codes. All they could do is infer from traffic analysis and sightings of US aircraft leaving and returning to Midway. Was this very strong? Probably not as strong as our information prior to the beginning of the operation, but strong enough to warrant a reevaluation of their plan.
 However, they apparently did not think it was that important. At least Captain Kuroshima the plans designer felt that it wasn't. Again, we don't really know, absolutely, that the information wasn't transmitted to Nagumo or that he got the information from one of his ships. Fuchida says that they were in the dark.


Did overconfidence play a part? Most historians say that it did, you know "victory disease". Yamamoto believed that with four fleet carriers against our two carriers, plus his experienced crews, Nagumo should have no problem. He was also counting on the cordon of submarines to possibly nail one or more carriers as they left and traveled north to the Aleutians.


Now, one interesting bit information is that Admiral Kusaka, the First Striking Fleet Chief of Staff to Nagumo, stated after the war that the First Air Fleet staff and himself were against the operation. They felt that the ships needed repairs, the pilots needed to be transferred to shore duty to train new pilots and the air groups rebuilt. This has much to say about it. However, as we know, Yamamoto was in a hurry. He knew his six months were almost up. So, what does it say about the First Striking Fleet?  Admiral  Kusaka said. "“We Japanese slighted the strength of the Americans and got self-conceited because of easy successes in the first stage of operations,” he wrote bluntly. “In other words, we thought that the enemy could be easily destroyed even if it did come out to meet our force.” Certainly Nagumo, although he shared Kusaka’s views about the condition of his force, had no doubt that his fleet could carry out successfully any task Yamamoto gave them." Yup, sounds like victory disease to me. Possibly that cinches it, they might have gotten the information and decided that it made no difference. So, despite their reservation about the crews, aircraft and ships, they had unflinching confidence no matter the odds against them, to be able to beat us anytime.

Here is another comment...by Admiral Yamamoto himself. "At 1800 on April 29 Yamamoto, somewhat irritated by the general atmosphere of self-congratulation, ended the review session with a short speech of warning: “Unless more efforts based upon long-range planning are put into military preparations and operations, it will be very hard to win the final victory,” he stated emphatically. “It is like a disease to think that an invincible status has been achieved after being satisfied with the past successful operations.” Seems Admiral Yamamoto detected this victory disease and realized what it might do to the upcoming operation. He was right I believe.

Prange, Gordon W.; Goldstein, Donald M.; Dillon, Katherine V.. Miracle at Midway (Kindle Location 806). Open Road Media. Kindle Edition.

[oldpop2000]

I have many books on the Midway battle and PDF documents many of them translations of IJN documents. I've noticed, especially in "Miracle at Midway" by Gordon Prange a consistent attitude of both the Japanese press and government officials that the " enemy was virtually kaput!". Here is one example from the Japan Times and Advertiser dated May 13, 1942:

“These [U.S.] naval defeats suffered since the beginning of the War of Greater East Asia practically eliminates [sic] all possibility of a major future naval engagement in the Pacific between Japan and the United States. The main fleet of the American Navy is resting at the bottom of the Pacific and it is doubtful whether the United States can send another fleet over to the Pacific.”

Here is the comment by Prange, which I totally agree with; "Such cool assumption of superiority is not the healthiest attitude to encourage in a navy preparing for “a major future naval engagement.” A little less of it, and the Japanese might have rushed the repairs and replenishing of Shokaku and Zuikaku to the point of participation at Midway. And even considering their low opinion of American efficiency and fighting spirit, the Japanese should have remembered an old Chinese proverb: “A lion uses all its might in attacking a rabbit.”

Another comment that adds emphasis to this idea of the assumption of superiority is this one:

"Only with the background of this atmosphere of exultant drive for conquest, of pride and arrogance, can one understand the Midway story. Only in this context of euphoric self-confidence can one appreciate how the meticulous planning, training and security of the Pearl Harbor attack went by the board in less than six months. The thick shower of journalistic roses buried the unhappy fact that the Nagumo task force was going forth to war “with meager training and without knowing the enemy.” Certainly the Japanese planning for Midway shows no evidence of such first-hand, evidential intelligence as had accompanied every step of the planning for the Pearl Harbor attack.......Yamamoto and his staff had no way of looking into the minds of Nimitz and his planners. It was a disadvantage which Nagumo underscored heavily: “… we had practically no intelligence concerning the enemy. We never knew to the end where and how many enemy carriers there were.”

It is my opinion, that the assumption of superiority which was pervasive in the press and hence in the navy along with the poor training and intelligence that lead up to the initiation of the operation doomed this operation from the beginning. I believe that radio silence was a vital factor, because even Nagumo commented that their intelligence was poor, so I believe that if Yamamoto had sent to Nagumo the vital information that A. Operation K, the intelligence operation was cancelled B. The cordon of submarines, also vital for intelligence had not been coordinated in time C. That Naval Intelligence in Tokyo due to traffic analysis had suspected that our carriers were operating near Midway. He might have reviewed that information with his staff, and they might have changed their scouting plan and their attack plan on Midway. I believe strongly that even with the attitude of "Victory Disease", a good staff would have viewed this new intelligence update as important and the plan could have been modified and should have.

[oldpop2000]

Here is another issue that I hadn't considered and that might have had an effect on the speed of decision made at the highest levels. Radio Silence would have played a part in this particular issue.
Nimitz was always a step ahead of Yamamoto, not because of his intelligence team and information derived from their work, but because he, unlike Yamamoto, was on the land, in his headquarters at the center of the fleet activity. Yamamoto was 300 miles behind Nagumo, on board Yamato. As Prange comments; " The day of the sea-going commander in chief was as passé as the battleship itself, a fact which Yamamoto did not realize. The problems of communications alone forbade such gallant but futile gestures as he was making. How to get in touch with his ships without betraying his whereabouts plagued Yamamoto all through the cruise and during the sea fight that followed. " I haven't seen this comment anywhere else, but I believe it has merit and could be a sleeper as to how the battle unfolded and why they lost. With the CinC of the Combined Fleet is about 2500 miles out to see in a ship with atmospherics affect low to medium wave radio communications, 25 US submarines lurking between him and Midway, a few others stationed outside the Bungo Straits waiting for ships to exit Hashirajima, you might want to be careful of your radio communications. It can give you away and put you at risk, this was a factor with the Main Fleet following behind Nagumo. It plagued Yamamoto throughout the voyage and battle. It also delays any changes that might be necessary based on new intelligence information. With Nimitz, he was next to his sources, could review them with his staff and send updates to his forward commanders, this kept the US Fleet ahead of the Japanese fleet throughout the battle. For Yamamoto, it was complete opposite, the information had to be send to him and hopefully he got it, but who knows how long this would take. He and his staff had to review the information, make changes and send them to the units scattered all over the Pacific from the Aleutians to Saipan to Midway. No wonder he was always behind Nimitz.

Radio Silence then had two basic reasons for affecting operations: Protection of Yamamoto and his staff in their floating headquarters; Japanese pervasive view that more intelligence did not matter because the US fleet was at the bottom of the Pacific and no matter what we did, the IJN would win. So why jeopardize the plan with more intelligence updates. The US was going to conduct the battle just as the staff had gamed it back at Hashirajima, and there was no reason to worry. Again victory disease and a Japanese propensity to plan for what we would do, instead of what we could do. This type of planning got the IJN into trouble on more than one occasion throughout the war.

Prange, Gordon W.; Goldstein, Donald M.; Dillon, Katherine V.. Miracle at Midway (Kindle Locations 2659-2661). Open Road Media. Kindle Edition.

[steel selachian]

The other effect of that was to more or less take one of the most powerful IJN assets - the 1st Battleship Division with Yamato, Nagato, and Mutsu - completely out of the equation. Granted they would have slowed Nagumo down and their AA was nowhere near as effective as the later US BBs, but a) it would have been some help and b) having those ships up at the front would have given the Japanese a better opportunity to close in and conduct a surface night attack. Instead they had an overly expensive mobile command post too far away from the action to do any good.

Additionally, given the fate of Yamamoto and his immediate successor Koga, putting the C-in-C of the Combined Fleet on the front lines was not the wisest policy.

[oldpop2000]

There have been comments that possibly that 1st Battleship division, even with its four knots deficit in speed might have been handy sailing close to the carriers. Their added AAA fire might have been able to protect the carriers better although separating the four carriers into two task forces probably would have been better. However, with the euphoric Japanese attitude about this time, I don't think they even considered the possibility that they would be ambushed and four carriers sunk. We know that Nagumo, Kusaka and many on the staff including Genda had reservations about the lack of intelligence compared to the Pearl Harbor Operation; couple this with the decidedly weaker air groups and training and it had to have occurred to many that conditions were not favorable but they felt that our fleet was sunk, so why worry. I don't understand why Coral Sea and Operation MO didn't give them even a whit of interest in how we were at the right place at the right time.

I believe that failing to pass newly gathered intelligence, so vital to the progress and execution of a plan, was the primary failure in the operation. The mistakes made on 4/5 June 1942 can be explained by the lack of updated intelligence. But as we have seen many times throughout the war, the Japanese executed a plan based on what we would do, not on what we could do. This type of planning and execution is a primary reason for their losses in many campaigns.

I do agree that Yamamoto, sailing in those battleships behind Nagumo was a wasted effort using fuel the Japanese Navy just did not have in storage. They only had about 2-2.5 years available of regular sailing stored and this operation used most of that. On the other hand, if you are planning to only have to fight for about six months, and we would give up, then it makes sense. But putting your most revered commander in jeopardy, doesn't make sense. With hindsight, I am certain that the many Japanese officers felt that the operation was planned and executed far too quickly and that more planning and training should have been completed. Again, Yamamoto's belief that he had to win within six months might have been a deciding factor in the speed with which the operation was begun.