Editing Attack on Pearl Harbor (section)

===Military planning===
[[File:Japanese attack plan at Pearl Harbor, Japan, 1941.jpg|thumb|The [[Empire of Japan]]'s 1941 attack plan on [[Pearl Harbor]]]]
Preliminary planning for an attack on Pearl Harbor to protect the move into the "Southern Resource Area", the Japanese term for the Dutch East Indies and Southeast Asia generally, began early in 1941 under the auspices of Admiral [[Isoroku Yamamoto]], then commanding Japan's [[Combined Fleet]].<ref name=Gailey1997p68>{{Harvnb|Gailey|1997|p=68}}</ref><ref>[https://www.gilderlehrman.org/history-resources/spotlight-primary-source/japanese-announcement-attack-pearl-harbor-1941 ''Japanese announcement of the attack at Pearl Harbor, 1941.''], "History Resources", The Gilder Lehrman Institute of American History, New York (USA), retrieved 18. Dezember 2023.</ref> He won assent to formal planning and training for an attack from the [[Imperial Japanese Navy General Staff]] only after much contention with Naval Headquarters, including a threat to resign his command.<ref name=Gailey1997p70>{{Harvnb|Gailey|1997|p=70}}</ref> Full-scale planning was underway by early spring 1941, primarily by Rear Admiral [[Ryūnosuke Kusaka]], with assistance from Commander [[Minoru Genda]] and Yamamoto's Deputy Chief of Staff, Captain Kameto Kuroshima.<ref>{{Harvnb|Lord|1957|pp=12–14}}</ref> The planners studied the [[Battle of Taranto|1940 British air attack on the Italian fleet]] at [[Taranto]] intensively.{{refn|"The Dorn report did not state with certainty that Kimmel and Short knew about Taranto. There is, however, no doubt that they did know, as did the Japanese. Lieutenant Commander Takeshi Naito, the assistant [[Military attaché|naval attaché]] to Berlin, flew to Taranto to investigate the attack first hand, and Naito subsequently had a lengthy conversation with Commander [[Mitsuo Fuchida]] about his observations. Fuchida led the Japanese attack on December 7, 1941."<ref>{{Harvnb|Borch|Martinez|2005|pp=53–54}}.</ref>|group=nb}}{{refn|"A [[torpedo bomber]] needed a long, level flight, and when released, its conventional torpedo would plunge nearly a hundred feet deep before swerving upward to strike a hull. Pearl Harbor deep averages 42 feet. But the Japanese borrowed an idea from the British carrier-based torpedo raid on the Italian naval base of Taranto. They fashioned auxiliary wooden tail fins to keep the torpedoes horizontal, so they would dive to only 35 feet, and they added a breakaway "nosecone" of soft wood to cushion the impact with the surface of the water."<ref>{{Harvnb|Gannon|1996|p=49}}</ref>|group=nb}}

Over the next several months, pilots were trained, equipment was adapted, and intelligence was collected. Despite these preparations, Emperor [[Hirohito]] did not approve the attack plan until November 5, after the third of four [[Gozen Kaigi|Imperial Conferences]] called to consider the matter.<ref>{{Harvnb|Wetzler|1998|p=39}}.</ref> At first, he hesitated to engage in war but eventually authorized the Pearl Harbor strike despite dissent from certain advisors.<ref name = "nuclearm">{{cite web | url=https://ahf.nuclearmuseum.org/ahf/profile/emperor-hirohito/#:~:text=The%20emperor%27s%20office%20signed%20off,his%20ability%20to%20do%20so | title=Emperor Hirohito - Nuclear Museum }}</ref> Final authorization was not given by the emperor until December 1, after a majority of Japanese leaders advised him the Hull note would "destroy the fruits of the China incident, endanger Manchukuo and undermine Japanese control of Korea".<ref>{{Harvnb|Bix|2000|p=417}}, citing the Sugiyama memo</ref> Before the attack, he became more involved in military matters, even joining the Conference of Military Councillors, which was considered unusual for him.<ref name="nuclearm"/> Additionally, he actively sought more information about the war plans.<ref name="nuclearm"/> According to an aide, he openly displayed happiness upon hearing about the success of the surprise attacks.<ref name="nuclearm"/> 

By late 1941, many observers believed that hostilities between the United States and Japan were imminent. A [[Gallup poll]] just before the attack on Pearl Harbor found that 52% of Americans expected war with Japan, 27% did not, and 21% had no opinion.<ref name="cipo19411208">{{cite news |url=https://news.google.com/newspapers?id=RPcuAAAAIBAJ&pg=5721%2C1471377 |title=Gallup Poll Found 52 p.c. of Americans Expected War |work=Ottawa Citizen |date=December 8, 1941 |access-date=November 28, 2011 |author=The Canadian Institute of Public Opinion |page=1 |url-status=live |archive-date=August 12, 2021 |archive-url=https://web.archive.org/web/20210812143117/https://news.google.com/newspapers?id=RPcuAAAAIBAJ&pg=5721%2C1471377}}</ref> While American Pacific bases and facilities had been placed on alert on many occasions, officials doubted Pearl Harbor would be the first target; instead, they expected the Philippines to be attacked first. This presumption was due to the threat that the air bases throughout the country and the naval base at Manila posed to sea lanes, as well as to the shipment of supplies to Japan from territory to the south.{{refn|Noted by [[Arthur MacArthur Jr.|Arthur MacArthur]] in the 1890s.{{sfn|Manchester|1978|p={{page needed|date=December 2021}}}}|group=nb}} They also incorrectly believed that Japan was not capable of mounting more than one major naval operation at a time.{{sfn|Evans|Peattie|1997}}{{page needed|date=December 2021}}