When the first week of June as it relates to World War II is mentioned, most of the time the reference is to the D-Day Invasion of Normandy on June 6, 1944. This event was arguably the most significant event in the European Theater of the war. But an equally important event took place June 4-7, 1942, two years earlier in the Pacific when the U.S. Navy defeated the Imperial Japanese Navy in the Battle of Midway.
Background: Midway is a tiny island in the middle of the Pacific Ocean about 1,200 miles northwest of Oahu. It’s significance if captured by the Japanese would enable them to control the area west of Hawaii, and bring the Hawaiian bases into range of Japanese long-range bombers. This factor resulted in U.S. Admiral Chester Nimitz being given the standing order by the U.S. Navy’s top command to defend the line of longitude that ran through Midway Island, as well as keeping the sea lanes open to Australia. The job became tougher after the Battle of Coral Sea—the first naval engagement in history to take place without the ships of either opposing navy coming into contact with each other at sea. During this battle, the already wounded U.S. Navy lost the U.S.S. Lexington, one of its largest and best aircraft carriers. Further the U.S.S. Yorktown, accompanying the Lexington, was severely damaged. To top it off, the U.S. Naval Combat Intelligence at Pearl Harbor was reporting signs that the Japanese were planning another attack in the near future. This began with a message intercepted in March by a Japanese pilot in the central Pacific who indicated he was passing over “AF,” that might be the code name of the Japanese’s next objective.
The Role of Code Breakers: Code breaking during World War II was not a perfect science. Messages that were intercepted had to be decoded to be understood, and the code needed to be broken for the message to be decoded. Without a codebook the codebreaking process moved along inch by inch. Nonetheless, working diligently for long hours at Naval Intelligence in Hawaii, Lt. Commander Joseph Rochefort and his code breakers gradually got to understand about twenty to twenty-five per cent of an intercepted message. From this piecemeal information and the body of previously decoded messages, they could reasonably discern what the messages were saying taken together. Rochefort and the code breakers believed that “AF” had to be Midway, as that was the only useful military target that the pilot could possibly have seen.
Washington Unconvinced: The U.S. Navy’s high command in Washington was unconvinced, and didn’t want Nimitz to commit his dwindling naval resources to an unconfirmed, risky purpose. To remedy this, Rochefort sent a message to Midway via submarine that said that Midway’s fresh water condenser was broken, with instructions to send it back through the airways via the open emergency channel. Because of the importance of the fresh water condenser to the base, the uncoded message via the emergency channel could be viewed by the Japanese as not fake and important enough to relay to their central command. The trick worked. Two days later the Japanese relayed the message saying that “AF” had a problem with its fresh water supply. This confirmed that all the activity connected with code name “AF” pertained to Midway. The Japanese inadvertently helped the process by not changing their code until June 1. By that time Rochefort and his department were interpreting up to ninety percent of some of the coded messages confirming Japanese strengths, ships involved, the timing of the upcoming operation, and more. The message became loud and clear that the Japanese were sending a fleet of four fully armed aircraft carriers to Midway.
Land Based Attacks: This information was all that Nimitz needed to send the remainder of the serviceable Pacific Fleet to Midway. He had three carriers at his disposal—the U.S.S. Hornet, U.S.S. Enterprise, and U.S.S. Yorktown. The Naval Shipyard at Pearl Harbor worked furiously to repair as much damage as they could to the Yorktown within a forty-eight-hour time limitation to get the ship back to sea and out to Midway to join the other two carriers. When scout planes from Midway spotted the Japanese fleet, a consortium of U.S. Army/Air Force, U.S. Marine Corps, and U.S. Navy planes based on Midway were dispatched to attack the Japanese fleet. This air armada scored only one inconsequential hit, and returned to Midway after suffering some losses. Shortly thereafter the Japanese launched a major attack on the bases at Midway destroying much of the land-based air forces in the process. However, the air attacks coming from the land-based force on Midway continued and may have forced Japanese Admiral Chuichi Nagumo to order another strike on Midway to prevent any more attacks.
Changing Armaments: To attempt a second attack on Midway, the Japanese would be forced to change armaments on their warplanes from torpedoes, meant for the U.S. ships, to bombs. This caused a tremendous amount of confusion and stress on the ships’ crews, and resulted in the torpedoes remaining in the ships’ hangars rather than being returned to the magazine. Further, the planes that returned from the first attack needed to be refueled as well as rearmed. When the U.S. Fleet was reported to be nearby, Nagumo changed his orders to prepare for an attack on that target, causing the rearming process to be reversed. This soon left the Japanese fleet highly vulnerable in the middle of the battle for a precarious amount of time. Further, it was against the orders of Admiral Isoroku Yamamoto, the Commander in Chief of the Imperial Japanese Navy, who ordered Nagumo to keep two carriers ready for an attack on the U.S. fleet whenever it arrived.
The Submarine: While the air attacks on Midway were going back and forth, the U.S.S. Nautilus, a submarine, ventured near the middle of the Japanese fleet formation while submerged. Although being badgered by escort vessels, the Nautilus managed to fire a series of torpedoes at ships in the fleet’s nucleus. No hits were made, and the Nautilus had to dive out of the way as it was being pursued by the Japanese destroyer Arashi. It took considerable time for the Arashi to press attacks on the Nautilus leaving them behind the fleet that was sailing away toward the U.S. Fleet sighting. At the same time, the U.S. carriers launched an air attack on the Japanese fleet. Owing to certain mechanical difficulties, this attack could not be coordinated with fighter planes accompanying the torpedo planes and dive bombers. The torpedo planes were launched first, but they were all shot down and failed to score a single hit. One squadron of dive bombers flew around the area where the Japanese fleet was at the time of the Midway land base strike. But the fleet had moved, and they were unable to detect in which direction. Then Commander Wade McClusky and his dive bombers spotted the Arashi apparently returning toward the fleet. They followed the ship in and discovered the fleet, signaling the fleet’s position to the other U.S. ships and planes. The Japanese fleet had no air cover available at that exact moment. McClusky’s planes attacked and scored several hits on the unprotected aircraft carriers. Further, several of the bombs penetrated the flight decks causing massive fiery explosions from the haphazardly stored torpedoes.
More Action: Just when Commander McClusky’s squadron attacked, two more squadrons of U.S. dive bombers arrived and also attacked causing an exploding, fiery mayhem for three of the Japanese carriers. This surely provided an awful moment for Nagumo whose forces were unable to defend themselves. The decisive edge turned to the U.S. Navy in a matter of about twenty minutes. However, the fourth carrier was off to the side out of the formation owing to the submarine’s failed torpedo attacks. Two days later the fourth carrier was spotted and sunk. The Japanese were only able to find and attack the U.S.S. Yorktown which was behind the Enterprise and Hornet owing to its delayed start from Pearl Harbor. After two attacks, the Yorktown was abandoned, and a ship was hooked up to tow the remainder back to Pearl Harbor. A day later, the stricken carrier was spotted by a Japanese submarine and sunk. All things considered the underdog U.S. Navy had won an amazing victory.
Conclusion: Two seemingly innocuous events had a colossal impact on the outcome of the battle. The first one was the Japanese pilot flying over the central Pacific and calling out the code name for a potential target objective. The second one was the Japanese destroyer Arashi trying aggressively to sink a submarine that had penetrated the Japanese fleet’s nucleus. The sighting of “AF” by the pilot was confirmed by Naval Intelligence giving Admiral Nimitz the knowledge he needed to commit the remaining fleet to the battle. The Arashi left a trail back to the Japanese fleet for some lost U.S. bomber pilots to follow. The Battle of Midway was not decisive—the Imperial Japanese Navy still remained a powerful force. Historians argue that it was not even the turning point in the Pacific War as the ensuing fighting in the Solomon Islands had more of a hand in turning the war’s direction. But without the victory at Midway, the turning point may have been much further away. Japan’s defeat forced it to end its expansion and begin its retreat. Three years and three months later it all ended for them on board the U.S.S. Missouri in Tokyo Bay.
Sources: How Codebreakers Helped Secure U.S. victory in the Battle of Midway, Sarah Pruitt, History.com, June 7, 2023.
Joe Rochefort’s War, Elliot Carlson.
Wikipedia, Battle of Midway.
Eagle Against the Sun, Ronald H. Spector.