Before the battle, Japan desired to extend its Pacific defense perimeter, especially after the Doolittle air raid of Tokyo in April 1942, and to clear the seas for attacks on Midway, Fiji, Samoa, and Hawaii.

Yamamoto's plan for the operation, which depended on precise timing and coordination, was undermined by its wide dispersal of forces, which left the rest of the fleet unable to support the Kidō Butai effectively.

Unknown to Yamamoto, U.S. code breakers had determined the date and location of his planned attack, enabling the Americans to prepare their own ambush; Chester Nimitz, commander of the Pacific Fleet, had sent a large force under Frank Jack Fletcher to the Midway area before the Japanese had arrived.

This concern was acutely heightened by the Doolittle Raid on 18 April 1942, in which 16 United States Army Air Forces (USAAF) B-25 Mitchell bombers launched from USS Hornet bombed targets in Tokyo and several other Japanese cities.

It was not especially important in the larger scheme of Japan's intentions, but the Japanese felt the Americans would consider Midway a vital outpost of Pearl Harbor and would be compelled to defend it vigorously.

[19] However, following hasty repairs at Pearl Harbor, Yorktown sortied and ultimately played a critical role in the discovery and eventual destruction of the Japanese fleet carriers at Midway.

Whereas many earlier historical accounts considered the Aleutians operation as a feint to draw American forces away, according to the original Japanese battle plan, AL was intended to be launched simultaneously with the attack on Midway.

[27] Nimitz also hurriedly recalled Rear Admiral Frank Jack Fletcher's task force, including the carrier Yorktown, from the South West Pacific Area.

[28] Despite estimates that Yorktown, damaged in the Battle of the Coral Sea, would require several months of repairs at Puget Sound Naval Shipyard, her elevators were intact and her flight deck largely so.

[34] Despite efforts to get Saratoga (which had been undergoing repairs on the American West Coast) ready, the need to resupply and assemble sufficient escorts meant she was unable to reach Midway until after the battle.

Although the fleet carrier Zuikaku escaped the battle undamaged, she had lost almost half her air group and was in port at the Kure Naval District in Hiroshima, awaiting replacement planes and pilots.

[43][nb 1] In addition, Nagumo's carrier force suffered from several defensive deficiencies which gave it, in Mark Peattie's words, a "'glass jaw': it could throw a punch but couldn't take one.

[56] At about 09:00 on 3 June, Ensign Jack Reid, piloting a PBY from U.S. Navy patrol squadron VP-44,[59] spotted the Japanese Occupation Force 500 nmi (580 mi; 930 km) to the west-southwest of Midway.

Japanese reconnaissance arrangements were flimsy, with too few aircraft to adequately cover the assigned search areas, laboring under poor weather conditions to the northeast and east of the task force.

[73] This experience may well have contributed to Nagumo's determination to launch another attack on Midway in direct violation of Yamamoto's order to keep the reserve strike force armed for anti-ship operations.

[86] Furthermore, by spotting and launching immediately, Nagumo would be committing some of his reserves to battle without proper anti-ship armament, and likely without fighter escort; he had just witnessed how easily the unescorted American bombers had been shot down.

Waldron's squadron sighted the Japanese carriers and began attacking at 09:20, followed at 09:40[100] by VF-6 from Enterprise, whose Wildcat fighter escorts lost contact, ran low on fuel, and had to turn back.

A few TBDs managed to get within a few ship-lengths range of their targets before dropping their torpedoes—close enough to be able to strafe the Japanese ships and force their carriers to make sharp evasive maneuvers—but all of their torpedoes either missed or failed to explode.

"[120] Another bomb exploded underwater very close astern; the resulting geyser bent the flight deck upward "in grotesque configurations" and caused crucial rudder damage.

Damage control parties were able to temporarily patch the flight deck and restore power to several boilers within an hour, giving her a speed of 19 kn (35 km/h; 22 mph) and enabling her to resume air operations.

[141] It was fortunate for the U.S. that Spruance did not pursue: had he come in contact with Yamamoto's heavy ships, including Yamato, in the dark, considering the Japanese Navy's superiority in night-attack tactics at the time, there is a very high probability his cruisers would have been overwhelmed and his carriers sunk.

Uncertain of whether they were friendly and unwilling to approach any closer to verify their heading or type, Murphy decided to send a vague report of "four large ships" to Admiral Robert English, Commander, Submarine Force, Pacific Fleet.

In the late afternoon of 6 June the Japanese submarine I-168, which had managed to slip through the cordon of destroyers (possibly because of the large amount of debris in the water), fired a salvo of torpedoes, two of which struck Yorktown.

SBD pilot Norman "Dusty" Kleiss, who scored three hits on Japanese ships during the Battle of Midway (aircraft carriers Kaga and Hiryū and heavy cruiser Mikuma), wrote: "From the experience in the Marshalls, at Wake and at Marcus, I thought our fleet learned its lessons.

[168] Japanese replacement pilots were pushed through an abbreviated training regimen to meet the short-term needs of the fleet, leading to a sharp decline in the quality of the aviators produced.

These inexperienced pilots were fed into front-line units, while the veterans who remained after Midway and the Solomons campaign were forced to share an increased workload as conditions grew more desperate, with few being given a chance to rest in rear areas or in the home islands.

[54] Although the Japanese continued to try to secure more territory, and the U.S. did not move from a state of naval parity to one of supremacy until after several more months of hard combat,[185] Midway allowed the Allies to switch to the strategic initiative, paving the way for the landings on Guadalcanal and the prolonged attrition of the Solomon Islands campaign.

[195] By the time of the Battle of the Philippine Sea in June 1944, the Japanese had nearly rebuilt their carrier forces in terms of numbers, but their planes, many of which were obsolete, were largely flown by inexperienced and poorly trained pilots.

[198] The Battle of Midway redefined the central importance of air superiority for the remainder of the war when the Japanese suddenly lost their four main aircraft carriers and were forced to return home.

Using advanced renavigation techniques in conjunction with the ship's log of the submarine USS Nautilus, the expedition located a large piece of wreckage, subsequently identified as having come from the upper hangar deck of Kaga.