Editing Battle of Midway (section)

==Prelude==
===American reinforcements===
[[File:G13065 USS Yorktown Pearl Harbor May 1942.jpg|thumb|{{USS|Yorktown|CV-5|6}} at [[Pearl Harbor]] days before the battle.]]

To do battle with the IJN, expected to muster four or five carriers, Admiral [[Chester W. Nimitz]], Commander in Chief, [[Pacific Ocean Areas]], needed every available flight deck. He already had Vice Admiral [[William Halsey]]'s two-carrier (''Enterprise'' and ''Hornet'') [[task force]] at hand, though Halsey was stricken with [[shingles]] and had to be replaced by Rear Admiral [[Raymond A. Spruance]], Halsey's escort commander.<ref>{{Harvnb|Prange|Goldstein|Dillon|1982|pp=80–81}}; {{Harvnb|Cressman|1990|p=37}}</ref> Nimitz also hurriedly recalled Rear Admiral [[Frank Jack Fletcher]]'s task force, including the carrier ''Yorktown'', from the [[South West Pacific Area]].<ref>{{Harvnb|Lord|1967|pp=23–26}}</ref>

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.<ref>{{Harvnb|Willmott|1983|p=337}}</ref> The [[Pearl Harbor Naval Shipyard]] worked around the clock, and in 72 hours she was restored to a battle-ready state,<ref>{{Harvnb|Cressman|1990|pp=37–45}}; {{Harvnb|Lord|1967|pp=37–39}}</ref> judged good enough for two or three weeks of operations, as Nimitz required.<ref>{{Harvnb|Willmott|1983|p=338}}</ref><ref>{{cite web |url=http://www.defensemedianetwork.com/stories/youve-got-three-days-repairing-the-yorktown-after-coral-sea/ |title=Battle of Midway: Repairing the Yorktown After the Battle of the Coral Sea |last=Zimmerman |first=Dwight |date=26 May 2012 |website=Defense Media Network |publisher=Faircount Media Group |access-date=21 January 2015 |archive-date=29 January 2016 |archive-url=https://web.archive.org/web/20160129123445/http://www.defensemedianetwork.com/stories/youve-got-three-days-repairing-the-yorktown-after-coral-sea/ |url-status=live}}</ref> Her flight deck was patched, and whole sections of internal frames were cut out and replaced. Repairs continued even as she sortied, with work crews from the repair ship {{USS|Vestal|AR-4|6}}, herself damaged in the attack on Pearl Harbor six months earlier, still aboard.<ref>{{Harvnb|Lord|1967|p=39}}; {{Harvnb|Willmott|1983|p=340}}</ref>

''Yorktown''{{'}}s partially depleted air group was rebuilt using whatever planes and pilots could be found. Scouting Five (VS-5) was replaced with Bombing Three (VB-3) from {{USS|Saratoga|CV-3|6}}. Torpedo Five (VT-5) was replaced by [[VA-35 (U.S. Navy)|Torpedo Three (VT-3)]]. Fighting Three (VF-3) was reconstituted to replace VF-42 with sixteen pilots from VF-42 and eleven pilots from VF-3, with [[Lieutenant commander (United States)|Lieutenant Commander]] [[John Thach]] in command. Some of the aircrew were inexperienced, which may have contributed to an accident in which Thach's executive officer Lieutenant Commander Donald Lovelace was killed.<ref>{{Harvnb|Willmott|1983|pp=340–341}}</ref> 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.<ref>{{Harvnb|Parshall|Tully|2005|pp=93–94}}</ref>

On Midway, the U.S. Navy had by 4 June stationed four squadrons of [[Consolidated PBY Catalina|PBYs]]—31 aircraft in total—for long-range reconnaissance duties, and six brand-new [[Grumman TBF Avenger]]s from ''Hornet''{{'}}s [[VT-8]].<ref>{{Harvnb|Scrivner|1987|p=8}}</ref> The Marine Corps stationed 19 [[Douglas SBD Dauntless]], seven [[Grumman F4F Wildcat|F4F-3 Wildcats]], 17 [[Vought SB2U Vindicator]]s, and 21 [[Brewster F2A Buffalo]]s. The USAAF contributed a squadron of 17 [[Boeing B-17 Flying Fortress|B-17 Flying Fortresses]] and four [[Martin B-26 Marauder]]s equipped with torpedoes: in total 122 aircraft. Although the F2As and SB2Us were already obsolete, they were the only aircraft available to the Marine Corps at the time.<ref>{{Harvnb|Parshall|Tully|2005|p=96}}</ref>

===Japanese shortcomings===
[[File:AkagiDeckApril42.jpg|thumb|{{Ship|Japanese aircraft carrier|Akagi||2}} (April 1942)]]

During the Battle of the Coral Sea one month earlier, the Japanese [[light carrier]] {{ship|Japanese aircraft carrier|Shōhō||2}} had been sunk, while the fleet carrier {{Ship|Japanese aircraft carrier|Shōkaku||2}} had been severely damaged and was in [[drydock]] for months of repair. Although the fleet carrier {{Ship|Japanese aircraft carrier|Zuikaku||2}} 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. That there were none immediately available can be attributed to the growing inability of the IJN to properly train pilots faster than they were killed in action. In desperation, instructors from the [[Yokosuka Air Corps]] were relieved of their duties to plug the gap.<ref name=Willmott101>{{Harvnb|Willmott|1983|p=101}}</ref>

Historians Jonathan Parshall and Anthony Tully believe that by combining the surviving aircraft and pilots from ''Shōkaku'' and ''Zuikaku'', ''Zuikaku'' likely could have been equipped with almost a full composite air group. They note, however, that doing so would have violated Japanese carrier doctrine, which stressed that carriers and their air groups must train as a single unit. (In contrast, American air squadrons were considered interchangeable between carriers allowing for more flexibility.) The Japanese apparently made no serious attempt to get ''Zuikaku'' ready for the forthcoming battle.<ref>{{Harvnb|Parshall|Tully|2005|pp=65–67}}</ref>

Thus, [[Fifth Carrier Division|Carrier Division 5]], consisting of the two most advanced aircraft carriers of the ''Kido Butai'', was not available which meant that Vice-Admiral Nagumo had only two-thirds of the fleet carriers at his disposal: {{Ship|Japanese aircraft carrier|Kaga||2}} and {{Ship|Japanese aircraft carrier|Akagi||2}} forming [[First Carrier Division|Carrier Division 1]] and {{Ship|Japanese aircraft carrier|Hiryū||2}} and {{Ship|Japanese aircraft carrier|Sōryū||2}} making up [[Second Carrier Division|Carrier Division 2]]. This was partly due to fatigue; Japanese carriers had been constantly on operations since 7 December 1941 including raids on [[Bombing of Darwin|Darwin]] and [[Indian Ocean raid|Colombo]].<ref>{{Harvnb|Parshall|Tully|2005|pp=63–64, 91}}</ref> Nonetheless, the First Carrier Strike Force sailed with 248 available aircraft on the four carriers (60 on ''Akagi'', 74 on ''Kaga'' (B5N2 squadron oversized), 57 on ''Hiryū'' and 57 on ''Sōryū'').<ref>{{Harvnb|Parshall|Tully|2005|pp=450–451}}</ref>

The main Japanese carrier-borne strike aircraft were the [[Aichi D3A]]1 "Val" [[dive bomber]] and the [[Nakajima B5N]]2 "Kate", which was used either as a [[torpedo bomber]] or as a level bomber. The main carrier fighter was the fast and highly maneuverable [[Mitsubishi A6M Zero]]. For a variety of reasons, production of the "Val" had been drastically reduced, while that of the "Kate" had been stopped completely and, as a consequence, there were none available to replace losses.<ref>{{Harvnb|Parshall|Tully|2005|p=89}}</ref> In addition, many of the aircraft being used during the June 1942 operations had been operational since late November 1941 and, although they were well-maintained, many were almost worn out and had become increasingly unreliable. These factors meant all carriers of the ''Kidō Butai'' had fewer aircraft than their normal complement, with few spare aircraft or parts in the carriers' hangars.<ref>{{Harvnb|Parshall|Tully|2005|pp=89–91}}</ref>{{refn|The code names "Val", "Kate" and "Zeke", which are often applied to these aircraft, were not introduced until late 1943 by the Allied forces. The D3A was normally referred to by the Japanese as ''Type 99 Navy dive bomber'', the B5N as the ''Type 97 Navy torpedo bomber'' and the A6M as the ''Type 0 Navy fighter''; the latter was colloquially known as the "Zero".<ref>{{Harvnb|Parshall|Tully|2005|pp=78–80}}</ref>|group=nb}}

In addition, Nagumo's carrier force suffered from several defensive deficiencies which gave it, in [[Mark Peattie]]'s words, a {{" '}}[[wikt:glass jaw|glass jaw]]': it could throw a punch but couldn't take one."{{sfn|Peattie|2007|p=159}} Japanese carrier anti-aircraft guns and associated fire control systems had several design and configuration change deficiencies{{clarify|date=May 2023|reason=What does "changes deficiences" mean?}} which limited their effectiveness. The IJN's fleet [[combat air patrol]] (CAP) had too few fighter aircraft and was hampered by an inadequate early warning system, including a lack of [[radar]]. Poor radio communications with the fighter aircraft inhibited effective command and control. The carriers' escorting warships were deployed as visual scouts in a ring at long range, not as close anti-aircraft escorts, as they lacked training, doctrine, and sufficient anti-aircraft guns.<ref>{{Harvnb|Parshall|Tully|2005|pp=85, 136–145}}; {{Harvnb|Peattie|2007|pp=155–159}}; {{Harvnb|Stille|2007|pp=14–15, 50–51}}</ref>

Japanese strategic scouting arrangements prior to the battle were also in disarray. A [[Picket (military)|picket]] line of Japanese submarines was late getting into position (partly because of Yamamoto's haste), which let the American carriers reach their assembly point northeast of Midway (known as "Point Luck") without being detected.<ref>{{Harvnb|Willmott|1983|p=351}}; {{Harvnb|Parshall|Tully|2005|pp=98–99}}</ref> A second attempt at reconnaissance, using four-engine [[Kawanishi H8K|H8K]] "Emily" [[flying boat]]s to scout Pearl Harbor prior to the battle and detect whether the American carriers were present, part of [[Operation K]], was thwarted when Japanese submarines assigned to refuel the search aircraft discovered that the intended refueling point—a hitherto deserted bay off [[French Frigate Shoals]]—was occupied by American warships because the Japanese had carried out an identical mission in March. Thus, Japan was deprived of any knowledge concerning the movements of the American carriers immediately before the battle.<ref>{{Harvnb|Lord|1967|pp=37–39}}; {{Harvnb|Parshall|Tully|2005|p=99}}</ref>

Japanese radio intercepts did notice an increase in American submarine activity and message traffic. This information was in Yamamoto's hands prior to the battle. Japanese plans were not changed; Yamamoto, at sea in {{Ship|Japanese battleship|Yamato||2}}, assumed Nagumo had received the same signal from Tokyo and did not communicate with him by radio, so as not to reveal his position.<ref>{{Harvnb|Parshall|Tully|2005|pp=102–104}}; {{Harvnb|Willmott|1983|pp=349–351}}</ref> These messages were, contrary to earlier historical accounts, also received by Nagumo before the battle began. For reasons that remain unclear, Nagumo did not alter his plans or take additional precautions.<ref>{{Harvnb|Parshall|Tully|2005|pp=101–102}}</ref>

===U.S. code-breaking===
Nimitz had one critical advantage: U.S. cryptanalysts had partially broken the Japanese Navy's [[JN-25b]] code.<ref name="MS-134">{{Harvnb|Smith|2000|p=134}}</ref> Since early 1942, the U.S. had been decoding messages stating that there would soon be an operation at objective "AF." It was initially not known where "AF" was, but [[Commander (United States)|Commander]] [[Joseph Rochefort]] and his team at [[Station HYPO]] were able to confirm that it was Midway: [[Captain (United States O-6)|Captain]] [[Wilfred Holmes]] devised a ruse of telling the base at Midway (by secure [[undersea communications cable]]) to broadcast an [[Plaintext|uncoded]] radio message stating that Midway's water purification system had broken down.<ref>{{cite web |url=http://www.nps.gov/nr/twhp/wwwlps/lessons/90midway/90facts1.htm |title=U.S. National Park Service: The Battle of Midway: Turning the Tide in the Pacific 1. Out of Obscurity |archive-url=https://web.archive.org/web/20150308182159/https://www.nps.gov/nr/twhp/wwwlps/lessons/90midway/90facts1.htm |archive-date=8 March 2015}}</ref> Within 24 hours, the code breakers picked up a Japanese message that "AF was short on water."<ref name="National Security Agency and the Central Security Service">{{cite web |title=The Battle of Midway: How Cryptology enabled the United States to turn the tide in the Pacific War |first=Patrick D. |last=Weadon |date=3 May 2016 |url=https://www.nsa.gov/about/cryptologic-heritage/historical-figures-publications/publications/wwii/battle-midway.shtml |website=NSA.gov |access-date=13 August 2024 |archive-date=18 September 2016 |archive-url=https://web.archive.org/web/20160918013823/https://www.nsa.gov/about/cryptologic-heritage/historical-figures-publications/publications/wwii/battle-midway.shtml}}</ref> No Japanese radio operators who intercepted the message seemed concerned that the Americans were broadcasting uncoded that a major naval installation close to the Japanese was having a water shortage, which Japanese intelligence might have suspected as deception.{{r|baker20160108}} HYPO was also able to determine the date of the attack as either 4 or 5 June, and to provide Nimitz with a complete IJN [[order of battle]].<ref name="MS-138-141">{{Harvnb|Smith|2000|pp=138–141}}</ref>

Japan had a new codebook, but its introduction had been delayed, enabling HYPO to read messages for several crucial days; the new code, which took several days to be cracked, came into use on 24 May, but the important breaks had already been made.<ref name="Willmott 1983 304">{{Harvnb|Willmott|1983|p=304}}</ref> As a result, the Americans entered the battle with a good picture of where, when, and in what strength the Japanese would appear. Nimitz knew that the Japanese had negated their numerical advantage by dividing their ships into four separate task groups, so widely separated that they were essentially unable to support each other.<ref>{{Harvnb|Parshall|Tully|2005|p=409}}</ref> This dispersal resulted in few fast ships being available to escort the Carrier Striking Force, thus reducing the number of [[Anti-aircraft warfare|anti-aircraft guns]] protecting the carriers. Nimitz calculated that the aircraft on his three carriers, plus those on Midway Island, gave the U.S. rough parity with Yamamoto's four carriers, mainly because American carrier air groups were larger than Japanese ones. The Japanese, by contrast, remained largely unaware of their opponent's true strength and dispositions even after the battle began.<ref name="Willmott 1983 304" />