The Battle of Midway: The Complete Intelligence Story


The Battle of Midway in June of 1942 was one of the most important naval battles in world history and a turning point in the Second World War. Between June 4 and 7, aircraft from aircraft carriers Enterprise, Yorktown, and Hornet of the U.S. Navy’s Task Forces 16 and 17 ambushed and sank the Imperial Japanese Navy’s carrier force that only six months before had attacked Pearl Harbor and terrorized the Pacific. The Battle of Midway is important to memorialize and remember for many reasons. Among these reasons is that it is an inexhaustible source of still-relevant lessons on how to successfully apply intelligence at all levels of war.

Intelligence Collection and Analysis

At the root of the American victory at Midway was U.S. Navy intelligence successfully breaking Japanese codes and discovering the Japanese Navy’s plans to attack Midway Atoll.

Station Hypo was the team of U.S. signals intelligence (SIGINT) analysts led by then-Commander Joseph “Joe” Rochefort. Immediately after Pearl Harbor, Station Hypo began attempting to decode messages transmitted using the JN-25 code. By late April, Rochefort’s team assessed that the Japanese were planning major operations against the central Pacific and Aleutians. In a famous trick, Pacific Fleet Commander Admiral Chester Nimitz approved a ruse proposed by Rochefort that saw the American garrison at Midway send a fake message “in the clear” (on open channels) regarding broken water evaporator units on the island. Almost immediately afterward, American listening posts intercepted Japanese transmissions mentioning the water shortage and the need to bring along extra water to support the operation. The identity of the Japanese objective was conclusively determined as Midway.

In his memoirs , Pacific Fleet Intelligence Officer Lieutenant Commander Edwin “Eddie” Layton recounted presenting the fruits of Hypo’s work on May 27th at the Pacific Fleet staff conference where the U.S. plans to ambush the Japanese force near Midway were approved, giving Nimitz a stunningly predictive assessment:

Summarizing all my data, I told Nimitz that the carriers would probably attack on the morning of 4 June, from the northwest on a nearing of 325 degrees. They could be sighted at about 175 miles from Midway at around 0700 local time.

On the morning of the battle, as the initial American reports sighting the Japanese force began to trickle in, Nimitz remarked to Layton with a smile, “well, you were only five minutes, five degrees, and five miles out.” Layton’s assessment allowed Nimitz to take a “calculated risk” by devoting three of his precious aircraft carriers (still scarce at that stage of the war) to the battle. The foreknowledge provided by this intelligence justified the presence off Midway of USS Yorktown (CV-5), damaged at the Battle of Coral Sea, but rushed back into action after a few days of frantic repairs at Pearl Harbor. This allowed the two U.S. task forces to roughly match the 229 planes onboard the Japanese carriers.

The penetrating knowledge and understanding of the Japanese demonstrated by Layton and Rochefort resulted both from technical proficiency in intelligence collection as well as an institutional and individual commitment to understanding the potential Japanese enemy. Both men were graduates of a program that detailed dozens of officers to study Japanese language and culture in Japan (with others similar studying China and Russia) during the interwar years.

Bizarrely absent from the debate in recent years over mandated STEM degrees for those seeking commissions as Navy officers has been any desire to incentivize foreign language training or skills for its intelligence personnel.  Despite the existence of the Foreign Area Officer (FAO) career field and the longstanding Olmsted Scholar program, where some officers (often on track to command) end up learning languages, it is discouraging to note a lack of interest in cultivating similar skills among Layton’s modern naval intelligence successors. If the Olmsted Foundation is the tool that the Navy is using to select and train foreign language experts for the officer corps overall, the Navy needs to look at other options because only eight naval intelligence officers have been selected for that program since 2008.

Intelligence, Surveillance, and Reconnaissance (ISR)

Intelligence also contributed to how the Battle of Midway was fought tactically. U.S. Navy tactics had evolved during the annual “Fleet Problems” conducted between 1923 and 1940. Several of the exercises involved “duels” between the carriers Lexington and Saratoga. The exercises revealed that the force that located and attacked the enemy carrier first generally won, demonstrating “the importance in carrier warfare of getting in the first blow.” Thomas Wildenberg has argued that these lessons led directly to the U.S. Navy’s development of the SBD Dauntless “scout bomber,” a carrier-borne aircraft with long range and ample payload for heavy ordnance designed to both find and drop bombs on enemy ships.

In contrast, the Japanese did not employ their carrier-borne aircraft for ISR. They instead used floatplanes based on battleships or cruisers to locate enemy ships, preferring to preserve their carrier air groups solely for strike missions. Wildenberg quotes Mitsuo Fuchida, commander of the air group embarked on the flagship Akagi, as stating that “in both training and organization our naval aviators [devoted] too much importance and effort . . . to attack.” Jonathan Parshall and Anthony Tully, the authors of Shattered Sword: The Untold Story of the Battle of Midway, attribute the Japanese preference for using aircraft in massed attacks derived from lessons learned in China.  In that theater, large numbers of aircraft were required for an attack to gain “decisive results.” Unlike airfields, however, aircraft carriers are mobile and hard to find in the middle of the ocean, and large bomber formations needed fighter escorts, thus not allowing the diversion of carrier-borne aircraft for large-scale scouting efforts.

Absent an expectation of American ships in the area and with Japanese carrier aircraft focused on the strikes against Midway in the early hours of June 4, Vice Admiral Chuichi Nagumo, commander of First Carrier Striking Force (commonly referred to as the “Mobile Force” in English) employed only a “skimpy” precautionary scouting effort to protect his task force, a move since criticized by historians and others writing about the battle.

The Japanese obsession with emphasizing airborne striking power directly at the expense of ISR can inform today’s debate over the mission of the U.S. Navy’s future carrier-borne unmanned aircraft. Critics of previous plans for the MQ-XX Stingray (once the UCLASS and CBARS) focused on its mission to provide carrier-based ISR in a “semi-permissive” environment. In the Navy’s most recent proposal, its primary missions will be to conduct airborne refueling and ISR. In particular, critics of an ISR-focused unmanned aircraft have raised concerns that:

the disproportionate emphasis in the requirements on unrefueled endurance to enable continuous intelligence, surveillance, and reconnaissance (ISR) support to the Carrier Strike Group (CSG) would result in an aircraft design that would have serious deficiencies in both survivability and internal weapons payload capacity and flexibility.

The desire of these critics for a stealthy carrier-borne unmanned strike platform is not necessarily wrong or misguided. But the success of the Dauntless scout bombers at Midway suggest that focusing solely on striking power at the expense of platforms with sensors that can locate and provide target-quality data to shooters could have the unintended consequence of creating a fleet lacking the tools to find the enemy.

Intelligence Dissemination

At Midway, the combination of an American edge in intelligence collection and analysis and Japanese ISR mistakes at the tactical level was complimented by multiple Japanese failures in disseminating intelligence and information. Tone 4, the Japanese floatplane that finally did detect the American task forces that morning, had launched late and deviated from its prescribed search path. How the report of Tone 4’s detection of the U.S. ships was transmitted is illuminating. The consensus has been that Nagumo received the message onboard Akagi indirectly via Tone around 0745. However, arguing that the composite logs compiled after the battle were inaccurate (the originals sank with the carriers), Dallas Woodbury Isom has claimed that Nagumo may not have received Tone 4’s report until after 0800. At this point, the American aircraft that would attack and sink three of the four Japanese carriers were already airborne. The plausibility of this scenario aside, it is not an optimal way to exercise command and control for vital information to travel indirectly from aircraft to cruiser and then to the flagship via the radio rooms of two ships before finally being hand-carried up to the flag bridge.

The Japanese Naval General Staff’s revised June 2 intelligence assessment also shows critical Japanese intelligence dissemination shortfalls. A few days before the battle, Japanese naval leadership ashore suspected that the Americans were aware of the Midway operation. The two versions of the story regarding how Nagumo received (or did not receive) that message both show flawed communications processes and technology.

Fuchida’s influential postwar account of the battle claimed that the revised intelligence was broadcast from Tokyo to both Nagumo and Combined Fleet commander Admiral Isoruko Yamamoto onboard the battleship Yamato, several hundred miles behind Nagumo’s task force. Yamamoto received the message aboard his flagship, but his staff convinced him to not relay it to Nagumo, assuming that the message had reached Akagi and that maintaining radio silence outweighed any additional warning. The inadequate antenna array onboard Akagi owing to the carrier’s small superstructure had not received the message, however.

Newer assessments of the battle like Parshall and Tully’s argue that this dissemination failure may not have been so egregious. They argue that the Japanese understood Akagi’s antennae inadequacies and had devised a system whereby the task forces’ surface combatants would serve as relays. Nagumo had received intelligence from Tokyo en route to Midway. His failure to anticipate the U.S. ambush resulted not from poor intelligence practices, but from inflexibility and institutional inertia. Even if this account of the battle is true, however, Japanese command and control practices were at best cumbersome and hindered the manner in which Nagumo could receive intelligence in a timely manner.

The U.S. Navy’s current aspirations toward networked warfare include “distributed lethality,” in which a “tactical cloud” of data is employed to create a “kill web,” increasing the range at which enemies can be detected and providing the afloat commander with different options to engage that adversary by linking sensors and shooters. Similarly, the Naval Integrated Fire Control-Counter Air (NIFC-CA) concept is a critical part of naval aviation’s current effort to network the entire carrier air wing (CVW) to maintain “situational awareness” and conduct “extended-range cooperative targeting.” Yet the challenges faced by the Japanese use of the 1942 version of networked communications demonstrate some of the disadvantages of spreading responsibility for collecting and transmitting data. While technically feasible, the processes the Japanese devised to pass information both from Tokyo and scouts like Tone 4 to their flagships performed poorly at Midway. The challenge for distributed lethality will be to ensure that the advantages of networked operations are not dependent on vulnerable communications paths and fragile transmissions that when broken may cripple decision-making.


The intelligence principles that demonstrated their value at Midway remain relevant in spite of the vast technological differences between today and 1942. The technical ability to collect information, the ability to contextualize, understand, and present that information as intelligence to commanders in a coherent and understandable way, the ability to employ tactical surveillance assets in order correctly detect and identify an adversary before it is able to do the same, and the ability to securely transmit that information to an afloat commander securely and swiftly will likely remain paramount in future conflict. What made such a victory possible was that the U.S. Navy outperformed its Japanese enemy in the collection, analysis, and dissemination of intelligence at the operational and tactical levels of war.


Lieutenant Commander Mark Munson is a Naval Intelligence officer currently assigned to United States Africa Command. The views expressed are solely those of the author and do not reflect the official viewpoints or policies of the Department of Defense or the U.S. government.

Image: Naval History and Heritage Command