The Pearl Harbor maritime base was perceived by both the Japanese and the United States Navies as a potential focus for unfriendly bearer air control. The U.S. Naval force had even investigated the issue amid a portion of its interwar "Armada Problems". Notwithstanding, its separation from Japan and shallow harbor, the assurance that Japan's naval force would have numerous other squeezing requirements for its plane carrying warships in case of war, and a conviction that insight would give cautioning convinced senior U.S. officers that the possibility of an assault on Pearl Harbor could be securely reduced.
Amid the interwar period, the Japanese had achieved comparable conclusions.

In any case, their squeezing requirement for secure flanks amid the arranged hostile into Southeast Asia and the East Indies prodded the dynamic administrator of the Japanese Combined Fleet, Admiral Isoroku Yamamoto to return to the issue. His staff found that the strike was possible, given the more noteworthy capacities of more up to date flying machine writes, changes to elevated torpedoes, an abnormal state of interchanges security and a sensible level of good fortunes. Japan's sentiments of franticness helped Yamamoto induce the Naval high order and Government to embrace the wander should war end up unavoidable, as showed up progressively likely amid October and November 1941.
Every one of the six of Japan's first-line plane carrying warships, Akagi, Kaga, Soryu, Hiryu, Shokaku, and Zuikaku, were relegated to the mission. With more than 420 left planes, these boats constituted by a wide margin the most intense transporter team at any point gathered. Bad habit Admiral Chuichi Nagumo, an accomplished, mindful officer, would order the task. His Pearl Harbor Striking Force likewise included quick war vessels, cruisers, and destroyers, with tankers to fuel the boats amid their section over the Pacific.
Under the best mystery, Nagumo took his boats to the ocean on 26 November 1941, with requests to prematurely end the mission on the off chance that he was found, or should discretion work an unexpected marvel.

Before sunrise on the seventh of December, unfamiliar and with strategic prospects solidly at an end, the Pearl Harbor Striking Force was under three-hundred miles north of Pearl Harbor. A first assault wave of more than 180 airships, including torpedo planes, abnormal state aircraft, jump planes and contenders, was propelled in the murkiness and took off toward the south.

At the point when first gathering had removed, a second assault wave of comparative size, yet with more jump aircraft and no torpedo planes, was raised from the bearers' shelter decks and sent off into the rising morning light. Close to Oahu's southern shore, the five smaller person submarines had just cast free from their "mom" subs and were endeavoring to advance into Pearl Harbor's tight passageway channel.