“I consider intelligence and public information to be in the same category; both are necessary evils,” was the remark made to me in all seriousness by a senior Navy captain. Unfortunately, this viewpoint is not an isolated one. All too frequently, one encounters this same negative and belittling approach. For even one senior officer in command of our operating forces to feel that intelligence is a necessary evil implies that he will not take timely steps to have at his fingertips every available bit of information about the enemy.
Perhaps by carefully examining several major naval engagements of recent times, paying particular attention to the role played by intelligence, it can be demonstrated how dangerous this negative approach to intelligence can be. At the same time, such an examination should help to make clear the importance of taking timely steps to obtain every available bit of information about the enemy. In this age of speed, where we measure time in seconds, not days, the word timely takes on an added significance.
Pearl Harbor
The disaster for America at Pearl Harbor is perhaps the most widely known example in recent times where the intelligence available to our commanders was not well used. By trying to guess what the enemy would do rather than prepare for what he was capable of doing, we left ourselves wide open. Here is the failure of Pearl Harbor! Our Commanders did not think the enemy would attack Pearl Harbor—it was not logical for him to do so. It was not even strategically wise for him to make such an attack. Therefore, as intelligence poured in, indicating Japanese naval and troop movements into the Southeast Asia area, our actions were based more and more on what we thought the enemy might do rather than exploring and making a correct estimate of everything he could do. Intelligence reported to Admiral Kimmel on 1 December 1941 indicated that since mid- November, the whereabouts of four Japanese aircraft carriers was unknown. No plans were made to cover the remote possibility that the carriers were moving eastward.
During the first eight months of 1941, there was much concern felt in the Hawaiian area about possible enemy air attack on Pearl. A war plan, published in May 1941, envisioned the probability of such an air attack. So one can hardly say that the problem was not seriously considered. Yet, after August, this danger seems to have faded from the minds of those responsible for the defense of this area.
On 17 August 1941, Admiral Stark, then CNO, wrote Admiral Kimmel, “Personally, I do not believe the Japs are going to sail into us.”
And in early December, at a joint Army- Navy briefing, the war plans officer on CinCPac’s staff told Admiral Kimmel and General Short that there would never be an air attack on Pearl Harbor.
Neither of these cited opinions by responsible officers is supported by the intelligence then available to these Commanders.
At 0342 on 7 December, over four hours before the attack on Pearl Harbor began, a submarine periscope was sighted off the entrance to Pearl Harbor. At 0645, one hour before the attack came, the USS Ward sank a submarine off the entrance. This vital clue to something happening was promptly reported but little was done to alert anyone who could take positive action until it was too late. Again we see the importance of timeliness in intelligence.
What is the significance of all this? It signifies to me a general lack of intelligence consciousness on the part of responsible officers of our Navy of that day. The tragic result of Pearl Harbor can be credited, in part at least, to failure by those in the chain of responsibility to recognize the vital importance of good intelligence to successful naval operations.
The intelligence agencies who were responsible for keeping their commanders informed must bear a share of the blame for the failures that occurred on that infamous day. Yet, there too, this blame really lay with the commanders for not recognizing the role of intelligence in staff organization and requiring the same high level of performance that was expected for the rest of the staff. If intelligence is considered an unwanted stepchild, top performance can hardly be expected. If the intelligence efforts of the staff are pushed aside in favor of hunches or guesses by the commander, what spur is there for the intelligence officer to put forth his best effort?
If Pearl Harbor was a crushing military defeat for us, for the Japanese it was a crowning victory, one whose success exceeded their best expectations. As a naval operation it was beautifully planned and well executed. The intelligence planning began years before by gathering detailed facts about our Navy and its bases. Our well established habit of spending weekends in port was duly noted. Our practice of scheduling operations well ahead and then announcing these schedules so personal plans could be made was a big help to those who would attack us. While schedules were not exactly public knowledge, so many people knew them that it did not take long for the Japanese intelligence effort in Hawaii to acquire them.
The exact layout of Pearl Harbor, with the regularly assigned shipberths, was well known to the Japanese Navy. They also knew where our operating areas were, the radio frequencies we employed, and the training we conducted. A copy of Jane's Fighting Ships or a visit to Pearl Harbor told them all they needed to known about the armament of our ships. To gather and keep intelligence current, an extensive collection net was employed. In addition to knowing to the last detail the enemy he was to face and where he would find him, his intelligence indicated that routing the Task Force well north of shipping lanes through rough, foggy weather would insure the greatest chance of surprise.
No wonder the Japanese were successful at Pearl Harbor. Nothing was left to chance or guesswork that could possibly be supplied as facts. This careful, painstaking attention to knowing the enemy paid off handsomely for the Japanese by giving the maximum achievement at minimum cost.
Now intelligence by itself accomplishes nothing. But combined with a well planned operation, carried out by highly trained pilots flying good aircraft, the results are there for all the world to see. This chain of military success was well forged with each link strong enough to carry its share of the load.
Coral Sea
The Battle of the Coral Sea was a strategic victory for American forces for it thwarted the Japanese plans to move into Port Moresby in southeast New Guinea. Tactically, however, it was a defeat. Our losses were greater than those suffered by the enemy and had this battle not been followed by the Battle of Midway, where the Japanese losses were catastrophic, the Battle of the Coral Sea would have been but a delaying action.
Nearly three weeks prior to the commencement of the Battle of the Coral Sea, accurate information on the composition of the Japanese forces moving down into the area, together with their time of arrival, was made available to the operational Commander. He was also given a correct evaluation of the strategic significance of these moves. That the strategic intelligence was adequate is borne out by the fact that we were ready to meet the enemy with the forces available to us in the area. But what about the tactical picture? From accounts of this engagement and the maneuvers leading up to it, one gets the impression that both the U. S. and the Japanese commanders expected that at the right time, the desired necessary information would somehow appear. From whence it would come is the unanswered question.
At one point during the engagement, the two main carrier forces passed with seventy miles of each other, each side blissfully unaware of the presence of the enemy. It is hard to understand why more effort was not made by both commanders to find out what the enemy was doing.
Fortunately for us, the Japanese made the same mistakes we did, thereby tossing the battle onto the gaming table of chance. Put bluntly, our successes were those of a gambler, not a planner.
This was the first naval engagement between carriers and mistakes were bound to occur. But the mistakes that did occur involved principles, not tactics. Finding the enemy is a principle as old as war itself. It was not nullified by the advent of the carrier.
A great deal of effort was expended in the early phases of the Battle of the Coral Sea by strikes against a minelayer reported as a cruiser, minesweeps reported as transports, and transports reported as seaplane tenders. Admittedly, identification of enemy units in combat is difficult. A few aviators demonstrated, however, that they could collect accurate information and report it correctly, thereby proving that it could be done. In retrospect, it appears that this phase of aviator training was deficient, a deficiency that could be traced, perhaps, to the failure to recognize the importance of collection of the information from which intelligence is made.
Fortunately for us, the Japanese commanders were so confident of success that they considered it unnecessary to make any real effort to find the U. S. Forces. Had they conducted routine searches, it seems very likely that the U. S. carriers would have been caught with their fueling hoses out, completely unready to engage the enemy.
We might well consider the Japanese mistakes fortunate ones, for they contributed to our success in the Coral Sea. But at the same time, the mistakes made by both sides clearly show the requirement for good intelligence in the successful conduct of naval operations.
Midway
No one can say that the U. S. Navy did not profit from the lessons learned in the Battle of the Coral Sea. In fact, one is probably right in concluding that the experience of the Battle of the Coral Sea was a necessary preliminary to the success that was ours at the Battle of Midway.
Here we have an engagement that is a nearly perfect example of the proper use of intelligence in battle. Samuel Eliot Morison in Coral Sea, Midway, and Submarine Actions1 stated, “Midway was a victory of intelligence, bravely and wisely applied.”
Nearly four weeks before Midway, Admiral Nimitz was given a fairly accurate idea of the Japanese plans and preparations. This intelligence picture enabled him to make his plans for the conduct of the battle and gather forces to be used. On 15 May from Washington came an estimate that an expeditionary force to capture Midway would depart Guam on 24 May. This added to the information already possessed by Admiral Nimitz and helped clarify the time schedule on which the Japanese attack on Midway was to develop.
Two weeks before the battle, Admiral Nimitz issued an estimate of the situation based on available intelligence that was accurate as far as it went. Shortly after this estimate of the situation was completed, an accurate forecast of the enemy plan of attack on Midway was made. We see here that information on the enemy was early and abundant. And, what is far more important, prompt and correct use was made of this intelligence. Here is where staff work often breaks down. Unless operations and planning personnel carefully follow the intelligence picture and the intelligence section carefully follows the operations and planning picture, two unfortunate things will happen: the greatest value will not be derived from the available intelligence, and the best possible intelligence will not be produced.
One of the most significant factors of the Battle of Midway was the reconnaissance. Here, certainly, our commanders demonstrated that they did not intend to commit the same mistakes we saw in the Battle of the Coral Sea. Six days before the battle, a daily 700-mile range air search plan was begun from Midway. For 1942, when strike aircraft in the 200-300-mile range class were high performance, this 700-mile search gave 24 hours strike warning to our forces.
In addition, special flights were flown to cover anticipated enemy carrier dawn launch points and to provide daily cover of suspected rendezvous points in the event the enemy eluded our regular air patrol.
Twelve submarines were stationed west and north of Midway on patrol stations. While their primary role was to strike the enemy, they were also there to provide valuable intelligence on the enemy forces that might venture near.
To complete the reconnaissance picture, once the carriers were in the area where contact with the enemy was possible, maximum range search missions were flown from the carriers themselves.
Despite a weather front which concealed the approaching Japanese forces, the occupation force was picked up at a range of 700 miles from Midway on the day preceding the carrier battle. Soon after sunrise on that memorable fourth of June, a patrol PBY sent a sighting report on the Japanese carrier force together with the information that carrier- based planes were heading for Midway. Even though the position of the ships was somewhat in error and only two of the four carriers had been sighted, both these items were most important intelligence. To the patrol plane pilot, the information about the strike planes on their way was to give Midway early warning, and for that purpose, it was good. But to the carrier commanders, this was vital intelligence. It told them that the movement of the enemy carriers was committed until these planes returned. It also enabled them to calculate the strike recovery time for these planes in the event Admiral Spruance wanted to take advantage of the maximum vulnerability of the enemy carriers. And finally, and this is most important, it indicated that the Japanese were not aware of the presence of U. S. carrier strike force in the area. For had they been, strikes against the carriers, not Midway, would have been the first order of business.
These two timely pieces of information set in motion a chain of events that sent three of the participating Japanese carriers to the bottom of the sea. Like the unsung lineman whose blocking enables a teammate to score, so did the intelligence collected by this PBY pilot permit his fellow aviators on the carriers to turn the tide of the battle in the Pacific. After the morning attacks against three carriers, ten scout bombers were launched from the USS Hornet. After searching for over three hours, a pilot reported the location of a carrier, two battleships, three cruisers, and four destroyers steaming north. This report was clear, concise, and accurate and brought forth the strikes that sank the fourth Japanese carrier destroyed in the battle of Midway. Without the accurate intelligence supplied by the pilot, it is likely that the Hiryu would have lived to fight another day.
Following this battle, Admiral Nimitz stated, “Had we lacked early information of the Japanese movements and had we been caught with our carrier forces dispersed, the battle of Midway would have ended differently.”
Why did the Japanese naval forces fail so completely at Midway after having been so successful from Pearl Harbor onward? If we look at Admiral Nagumo’s estimate of the situation in planning for Midway we will see why. The following statements are extracts from this estimate:
“1. Although the U. S. Navy lacks the will to fight, it will counterattack if Midway is occupied.
“2. The enemy is not aware of our plans.
“3. He has no carrier force in the vicinity.
“4. After attacking Midway by air and destroying American shore based air strength, the striking force would still have enough planes to destroy any enemy task force that might choose to attack.”
Here we have four statements that read more like wishful thinking than supportable facts. The first clearly shows how Japanese overconfidence had been built by their early successes. Certainly after Coral Sea, their feeling that we lacked the will to fight was not a valid one.
While every commander hopes that the enemy will not be aware of his next move, he can never be sure. Therefore his planning must take this possibility into account. This Admiral Nagumo’s planners failed to do.
Closely allied to the first statement is the assumption that the American commanders would not conduct a co-ordinated defense. Through a vigorous intelligence collection effort by an almost lavish use of reconnaissance aircraft, our commanders had the necessary intelligence with which to effectively co-ordinate the American effort.
With such a defective estimate of the situation, it is small wonder that the Japanese effort at Midway failed so completely. What a contrast we see here with the painstaking and detailed intelligence effort that the Japanese commanders put into the attack on Pearl Harbor.
Philippine Sea
The Battle of the Philippine Sea, with its famed “turkey shoot,” was certainly a U. S. victory. The power of our fifteen-carrier task force was too much for the numerically weaker Japanese forces, whose carriers were manned by inadequately trained air groups. The cream of Japanese naval aviation was lost at Midway and their replacements were, by our standards, poorly trained. Therefore, it is not surprising that we won handily.
Yet, we made one mistake of such gravity that had the battle been fought on even terms, we most probably would have been defeated.
This mistake was an almost complete neglect of reconnaissance. Except for the intelligence reported by the submarines as they skillfully went about their business of sinking ships, Admiral Spruance would not even have known that a battle with the Japanese fleet was shaping up.
What a contrast in this regard with Midway. There, poor as we were for aircraft of any sort, 22 patrol planes were committed to cover the expected battle area out to 700 miles from Midway. At Saipan only five seaplanes were committed to fly from a tender with twelve more operating from the Admiralty Islands, 1,000 miles south of the Marianas. How could they expect to get adequate intelligence on the location and movement of the Japanese forces with so few search aircraft? All through this battle, the Japanese commanders knew where the main American force was located, while the U. S. commanders could only guess where the Japanese forces were.
On 18 June Admiral Spruance received three good submarine contact reports which told him that several Japanese naval forces were heading towards the Marianas. He knew then that a battle with the Japanese Navy was likely. At 0115 on 19 June, one of the five patrol planes made radar contact with the Japanese main body. Yet, eight hours before this PBM made contact with the Japanese, Admiral Ozawa’s scout planes made contact with U. S. forces while they were still over 500 miles apart. The next day the Japanese used 43 search aircraft in three separate flights to make and hold contact with our forces. While they lost several search planes to our fighters, this was the price they had to pay for intelligence on the location and movement of our ships. All through the day, the Japanese hurled strike aircraft at our task groups, but they were unable to penetrate our defenses.
Though the plan of battle issued by Admiral Spruance called for our air power to knock out the enemy carriers as the first item of business, this could not be done, for Task Force 58 did not know where the enemy carriers were. So our forces devoted their efforts to defending themselves in a most successful manner.
After the last Japanese strike against our forces had been repelled and our aircraft were recovered with but very few losses during the day, Admiral Spruance sent Admiral Mitscher the following message: “Desire attack enemy tomorrow if we know his position with sufficient accuracy. If our patrol planes give us required information tonight no searches should be necessary. If not, we must continue searches tomorrow to insure adequate protection of Saipan.”
The battle had been joined for a day and still there was nothing definite on where the enemy was.
Finally, on the afternoon of the 20th, maximum range search aircraft were sent out from the carriers with the result that before 1600, the main Japanese Force was found. The decision was made to launch strikes immediately even though the planes would have to fly to the limit of aircraft range and then be recovered after dark, something the pilots of that time were not qualified to do. This was one of the “hard decisions” of the war, a calculated risk where the anticipated results overbalanced the expected losses.
It seems likely that had more adequate provisions been made for search and reconnaissance, both Admiral Spruance and Admiral Mitscher would have had good intelligence on the enemy force and its movements at least 24 hours earlier. And earlier intelligence could have made possible even greater success than was achieved.
Perhaps this failure can best be summed up by noting that fifteen admirals held various commands within task force 58, which was only one part of Admiral Spruances’ Fifth Fleet. Yet, at the same time, reconnaissance from Saipan was the responsibility of one lieutenant commander.
Following this battle, Admiral Spruance was subjected to considerable criticism for not taking off after the Japanese carriers in a bolder fashion. In retrospect, this bold approach might have brought about the destruction of a greater number of Japanese ships. Yet it would have been wrong for Admiral Spruance to accept this proposal for he could not properly leave his primary responsibility of protecting the Saipan landings until he knew the whereabouts of the Japanese Fleet. A vigorous reconnaissance effort could have provided the intelligence necessary to solve the dilemma the Admiral faced.
Atlantic Antisubmarine Warfare
Lest one might draw the false conclusion that it is only in air operations where timely and accurate intelligence is needed, let us shift the scene from the carrier air war in the Pacific to the antisubmarine warfare in the Atlantic. What part does intelligence play in controlling the seas against enemy submarines? Is it as important in the “ping, train, and listen” navy as it is in air warfare?
The first step in antisubmarine warfare, and by far the most difficult one, is that of finding the enemy submarine. In World War II, for every minute actually spent in attacking, hundreds of hours were spent gathering intelligence on where the enemy was. First he had to be found. This was done by sonar contacts, by radio direction finder fixes on submarine radio transmissions, and by visual sightings and radar contacts obtained from ships, blimps, and aircraft. Then, once contact was made, it had to be identified as an enemy submarine and attacked.
Now go back over this preceding paragraph. You will find that all but the last word deals with intelligence. Only the last word—attacked—is operational in nature. This is a mighty important part of the problem—for submarines are not sunk without being attacked. But at the same time, the hundreds of hours of intelligence collecting and evaluating effort that makes attack possible is equally important. No aspect of naval warfare requires as much intelligence collection effort as does antisubmarine warfare.
Once the Allies built up intelligence collection and attack forces, the effectiveness of the German submarine was first reduced, then neutralized, and finally destroyed. By taking full advantage of every means of finding the enemy, the problem that had been unsolvable when the war began was controlled by 1943. The cost was high, both in lives and monetary values, but the fact that in four short years it was solved at all makes it truly a Herculean accomplishment.
While all the preceding examples were taken from World War II in order that readers might draw on personal familiarity with this era, there are many other battles throughout the history of naval warfare that could have been used equally well to illustrate how important intelligence is to the successful conduct of naval operations. It doesn’t matter whether the weapons used are 32- pounder cannon or nuclear warheads, for one must first know the enemy and where he is before he can be attacked. In fact, as the tools of warfare become more destructive and the tempo of war is on the time scale of seconds, the vital importance of intelligence increases. No longer can we afford the luxury of a second chance. With prospect of the outcome of a war hinging on winning the first battle, there is no leeway for guesswork. Our commanders must know what can be expected from the forces they control, but they must also know each potential enemy, his capabilities and limitations, his weaknesses and strengths if the full potential of our Navy is to be used to best advantage.
1. Vol. IV of History of U. S. Naval Operations in World War II (Little, Brown & Company).